so, good luck to you all. or, congrats on surviving AP physics. depending on when you're reading this.
doc! and to all readers, there's been good times and bad times. thanks for a great year!
in favor of studying, my last "required" blog will be cut short, i think. i got a few tips on how to do this quickly and effectively.
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So. I was at my desk. Wondering what to write about. And then I remembered something. It was a time when I went through a revolving door. There's me going in like a boss. Force perpendicular to the radius to maximize torque. Like a boss. since torque = r F sin theta, i remembered that sin theta is 1 at 90 degrees.
Then there's Matt Lum. Show him how its done Grozen.
I do so bad on tests man, I remember this time I got like a 70 or something and posted about it on my blog. I might get a C this quarter. I saw kelly and jrad today. they were like, within 800 meters of each other. yup, thats scandalous
Monday, May 10, 2010
Monday, May 3, 2010
things that shine with the colors of a rainbow
Today, I noticed in the shower at some point, that a good number of the bubbles I made were clear and transparent but still shined with colors of a rainbow. It occurred to me that I had no idea why bubbles shine with the colors of a rainbow.
I found out the reason why bubbles shine with colors of the rainbow: the variety of colors was the result of thin-film interference.
When white light hits an object, some of it is reflected back. Thus causing the object to shine with the colors of a rainbow. Consider the following scenario for a bubble which shines with the colors of a rainbow:
When light bounces off the bubble, it undergoes a 180 degree phase change as it moves to a media with a higher index of refraction, a crucial first step in making it shine with the colors of a rainbow.
The rest of the light passes through the bubble and consequently reflects back without phase change at the second interface between air and bubble. This causes the white light waves to travel different lengths toward the same point.
Different things will happen when the light waves coincide. If the waves differ by 180 degrees, they will both shine with the colors of the rainbow. No, not really--no light will appear. If the waves coincide, light appears. Different colors within the visible light spectrum have different wavelengths and are affected differently while passing through a bubble. Wavelength and index of refraction are directly related; hence, when passing through the bubble, only certain colors will appear, thus making the bubble shine with colors of a rainbow.
PS: while looking at bubbles which shine like colors of a rainbow, i did not really fancy the idea of getting my camera wet. so i used someone else's which had a similar effect.
PPS:
@ david: if you don't look at it that way, it's not obscene. jesus.
I found out the reason why bubbles shine with colors of the rainbow: the variety of colors was the result of thin-film interference.
When white light hits an object, some of it is reflected back. Thus causing the object to shine with the colors of a rainbow. Consider the following scenario for a bubble which shines with the colors of a rainbow:
When light bounces off the bubble, it undergoes a 180 degree phase change as it moves to a media with a higher index of refraction, a crucial first step in making it shine with the colors of a rainbow.
The rest of the light passes through the bubble and consequently reflects back without phase change at the second interface between air and bubble. This causes the white light waves to travel different lengths toward the same point.
Different things will happen when the light waves coincide. If the waves differ by 180 degrees, they will both shine with the colors of the rainbow. No, not really--no light will appear. If the waves coincide, light appears. Different colors within the visible light spectrum have different wavelengths and are affected differently while passing through a bubble. Wavelength and index of refraction are directly related; hence, when passing through the bubble, only certain colors will appear, thus making the bubble shine with colors of a rainbow.
PS: while looking at bubbles which shine like colors of a rainbow, i did not really fancy the idea of getting my camera wet. so i used someone else's which had a similar effect.
PPS:
@ david: if you don't look at it that way, it's not obscene. jesus.
Sunday, April 25, 2010
Life Lessons #2: How to Escape from Quicksand
recently, my brother (and some friends) went on a camping trip in the high wilderness of Jersey. among the many pictures he showed me, I noticed a few shots of quicksand.
aside from seeing quicksand in video games and movies, I knew very little about how it worked. thankfully, I was enlighted by bill nye, the science guy.
interestingly enough, Bill asserts that quicksand will not "suck you down and make you disappear," but that drowning is an impossibility "ya wouldn't drown!" his explanation is that quicksand is simply a heavily concentrated mixture of sand and water--sinking in quicksand is as natural as sinking is water. all one needs to do is lie on his/her back, and wait minutes, days, or years for the next guy to come and save you.
just to check up on Bill Nye's claims, I found a source which stated something similar. pretty interesting!
"One of the most common reactions once a person finds his or her foot stuck is to shift weight to the other foot. At this point, a sort of seesaw motion happens -- with the person alternating their weight back and forth, trying to get a foot out of the quicksand. This movement actually worsens the predicament. What you should do instead is fall forward and try to spread the weight of your body over a large area of ground. Continue to work at freeing your foot, using slow motions so that you don't work your foot in deeper. Once you've pulled your foot out, roll away from the area, jump up very quickly and sprint to solid ground.
There have been many cases where people have gotten their legs trapped in quicksand and haven't been able to escape on their own. The sand has to be at just the right moisture for this to happen and the person has to be at least thigh-deep with both legs. Extricating a person from this takes at least two passersby, if not a full-fledged rescue team."
wow. lots of physics here. first, by shifting weight from a foot already locked into the ground to a different foot, the only thing one accomplishes is pushing the "other" foot harder into the ground. clearly, that will not work!
next, the source suggests spreading the weight of your body over as much area as possible. This is good advice to not only individuals stuck in quicksand, but people learning how to swim. spreading one's body over the water increases the amount of the body which is submerged, resulting in a greater force downward into the water. however, according to archimedes's principle, an equal and opposite force in magnitude (buoyant force) will keep you afloat. thus, spreading out your body, not struggling with your feet, will help you survive a quicksand attack.
finally, your success in the encounter with quicksand depends largely on how "concentrated" the quicksand is--the ratio of sand:water. While quicksand is normally much more dense than water, some breeds of quicksand probably contain high concentrations of water. Meaning, it would be a lot harder to float, and a lot easier to drown. The same effect can be observed when swimming: extremely salty water is much easier to float in, as highly concentrated salt water is much denser than fresh water.
so, if you ever encounter quicksand on your date with life, think:
1st) fluid mechanics--first, archimedes' principle, second, density.
2nd) get your phone and all electronics out, NOW.
3rd) if all else fails, you need to wait for some random dude to come help you. don't worry, if I ever see you stuck in a puddle of quicksand, i'll call 911 for sure.
source: http://science.howstuffworks.com/quicksand-sinking1.htm
aside from seeing quicksand in video games and movies, I knew very little about how it worked. thankfully, I was enlighted by bill nye, the science guy.
interestingly enough, Bill asserts that quicksand will not "suck you down and make you disappear," but that drowning is an impossibility "ya wouldn't drown!" his explanation is that quicksand is simply a heavily concentrated mixture of sand and water--sinking in quicksand is as natural as sinking is water. all one needs to do is lie on his/her back, and wait minutes, days, or years for the next guy to come and save you.
just to check up on Bill Nye's claims, I found a source which stated something similar. pretty interesting!
"One of the most common reactions once a person finds his or her foot stuck is to shift weight to the other foot. At this point, a sort of seesaw motion happens -- with the person alternating their weight back and forth, trying to get a foot out of the quicksand. This movement actually worsens the predicament. What you should do instead is fall forward and try to spread the weight of your body over a large area of ground. Continue to work at freeing your foot, using slow motions so that you don't work your foot in deeper. Once you've pulled your foot out, roll away from the area, jump up very quickly and sprint to solid ground.
There have been many cases where people have gotten their legs trapped in quicksand and haven't been able to escape on their own. The sand has to be at just the right moisture for this to happen and the person has to be at least thigh-deep with both legs. Extricating a person from this takes at least two passersby, if not a full-fledged rescue team."
wow. lots of physics here. first, by shifting weight from a foot already locked into the ground to a different foot, the only thing one accomplishes is pushing the "other" foot harder into the ground. clearly, that will not work!
next, the source suggests spreading the weight of your body over as much area as possible. This is good advice to not only individuals stuck in quicksand, but people learning how to swim. spreading one's body over the water increases the amount of the body which is submerged, resulting in a greater force downward into the water. however, according to archimedes's principle, an equal and opposite force in magnitude (buoyant force) will keep you afloat. thus, spreading out your body, not struggling with your feet, will help you survive a quicksand attack.
finally, your success in the encounter with quicksand depends largely on how "concentrated" the quicksand is--the ratio of sand:water. While quicksand is normally much more dense than water, some breeds of quicksand probably contain high concentrations of water. Meaning, it would be a lot harder to float, and a lot easier to drown. The same effect can be observed when swimming: extremely salty water is much easier to float in, as highly concentrated salt water is much denser than fresh water.
so, if you ever encounter quicksand on your date with life, think:
1st) fluid mechanics--first, archimedes' principle, second, density.
2nd) get your phone and all electronics out, NOW.
3rd) if all else fails, you need to wait for some random dude to come help you. don't worry, if I ever see you stuck in a puddle of quicksand, i'll call 911 for sure.
source: http://science.howstuffworks.com/quicksand-sinking1.htm
Monday, April 19, 2010
The Greenest Technology Company on the Planet
September 24, 2008
“Our customers have made it clear that they want the greenest technology possible,” Jeff Clarke, senior vice president, Dell Product Group said during the company’s mobility summit in Monte Carlo today. “As an industry, we can shape the future of green innovation and significantly reduce the carbon footprint associated with mobile computing. Dell is committed to leading the transition to energy-efficient LED technology.”
The "LED technology" which Clarke speaks of is none other than a light-emitting diode.
A light emitting diode is essentially a two-layered semiconductor—-it has both a p-type and a n-type semiconductor in a circuit. While current flows through the semiconductors, electrons from the conduction band of the n-type move towards the holes present in the p-type. As a result, the energy of the electron drops, and a photon is released with energy equivalent to the energy difference between the conduction to valence bands.
Fast forward to today, where owning a LED laptop is no longer an uncommon feat. This is great news for the environmentalists, as the benefits of LED technology seem endless:
"In addition to being mercury-free and highly recyclable, LED displays deliver significant energy savings compared to cold cathode fluorescent lamp (CCFL) technology. For example, Dell’s 15-inch LED displays consume an average of 43 percent less power at maximum brightness, resulting in extraordinary cost and carbon savings. The company estimates customer savings of approximately $20 million and 220 million kilowatt-hours in 2010 and 2011 combined, the equivalent of annual CO2 emissions resulting from energy use of more than 10,000 homes1."
I applaud Dell and its management in attempting to become the "Greenest Technology Company on the Planet."
source: http://www.dell.com/content/topics/global.aspx/corp/pressoffice/en/2008/2008_09_24_rr_000?c=us&l=en
“Our customers have made it clear that they want the greenest technology possible,” Jeff Clarke, senior vice president, Dell Product Group said during the company’s mobility summit in Monte Carlo today. “As an industry, we can shape the future of green innovation and significantly reduce the carbon footprint associated with mobile computing. Dell is committed to leading the transition to energy-efficient LED technology.”
The "LED technology" which Clarke speaks of is none other than a light-emitting diode.
A light emitting diode is essentially a two-layered semiconductor—-it has both a p-type and a n-type semiconductor in a circuit. While current flows through the semiconductors, electrons from the conduction band of the n-type move towards the holes present in the p-type. As a result, the energy of the electron drops, and a photon is released with energy equivalent to the energy difference between the conduction to valence bands.
Fast forward to today, where owning a LED laptop is no longer an uncommon feat. This is great news for the environmentalists, as the benefits of LED technology seem endless:
"In addition to being mercury-free and highly recyclable, LED displays deliver significant energy savings compared to cold cathode fluorescent lamp (CCFL) technology. For example, Dell’s 15-inch LED displays consume an average of 43 percent less power at maximum brightness, resulting in extraordinary cost and carbon savings. The company estimates customer savings of approximately $20 million and 220 million kilowatt-hours in 2010 and 2011 combined, the equivalent of annual CO2 emissions resulting from energy use of more than 10,000 homes1."
I applaud Dell and its management in attempting to become the "Greenest Technology Company on the Planet."
source: http://www.dell.com/content/topics/global.aspx/corp/pressoffice/en/2008/2008_09_24_rr_000?c=us&l=en
Monday, April 12, 2010
Dynamic Systems
for those of you reading this at school (and can only read this at school; owned!), I'm not sure if flash games are surf controlled, so I apologize in advance.
I struggled for awhile to find something in my house related to nuclear physics, so I decided that really, it wasn't worth the effort. I'd have to find something else. While procrastinating, I stumbled upon this nifty game thing called 'dynamic systems.'
The game is extremely simple at first, but gets exponentially harder within the first five levels. The idea is simple: initially, a silver ball is present on the board, somewhere far, far, away from the bucket. Using the random assortment of tools provided and properties of physics, one must place various objects which, when the ball is set into motion, will successfully make the ball fall into the bucket.
There is, of course, a "reset" option if your setup does not work. There is also a 'solution' button which obviously gives you the answer if you truly are stumped.
After playing with the game a bit, I'll be the first to admit that it gets extremely frustrating rather quickly. By the ninth level or so, I had no idea what the tools given to me or assorted machinery on the map would even do. Nevertheless, I saw gears, levers, even a windmill type thing which seemed to undergo uniform circular motion.
However, no matter how complicated the levels get, the key to beating each individual level is correctly visualizing what will happen to the ball as it passes each obstacle. Some tools they give you slow the ball down, probably displaying some effect of high friction. Others such as a ramp (which you can put at any angle) allow the control of how quickly the ball falls, and where it lands. On the fourth level, there are even domino blocks which cause a chain reaction through conservation of momentum.
For those of you who want to see what the game looks like but are too lazy to click the link of the actual game, I'll throw you a bone. Here's one of the first levels, where the setup is relatively easy. Notice how you can also rotate the various objects provided.
and for the rest of you, here's the game itself, along with a bunch of other "physics" related games.
I struggled for awhile to find something in my house related to nuclear physics, so I decided that really, it wasn't worth the effort. I'd have to find something else. While procrastinating, I stumbled upon this nifty game thing called 'dynamic systems.'
The game is extremely simple at first, but gets exponentially harder within the first five levels. The idea is simple: initially, a silver ball is present on the board, somewhere far, far, away from the bucket. Using the random assortment of tools provided and properties of physics, one must place various objects which, when the ball is set into motion, will successfully make the ball fall into the bucket.
There is, of course, a "reset" option if your setup does not work. There is also a 'solution' button which obviously gives you the answer if you truly are stumped.
After playing with the game a bit, I'll be the first to admit that it gets extremely frustrating rather quickly. By the ninth level or so, I had no idea what the tools given to me or assorted machinery on the map would even do. Nevertheless, I saw gears, levers, even a windmill type thing which seemed to undergo uniform circular motion.
However, no matter how complicated the levels get, the key to beating each individual level is correctly visualizing what will happen to the ball as it passes each obstacle. Some tools they give you slow the ball down, probably displaying some effect of high friction. Others such as a ramp (which you can put at any angle) allow the control of how quickly the ball falls, and where it lands. On the fourth level, there are even domino blocks which cause a chain reaction through conservation of momentum.
For those of you who want to see what the game looks like but are too lazy to click the link of the actual game, I'll throw you a bone. Here's one of the first levels, where the setup is relatively easy. Notice how you can also rotate the various objects provided.
and for the rest of you, here's the game itself, along with a bunch of other "physics" related games.
Saturday, April 3, 2010
Playing around with some purple light thing
saturday night, nothing much to do, and it was time for the physics blog. of course, the camera was in video mode by chance, but before I switched it to picture mode, my good friend Richard asked, "what's that?" Sure enough, there was a random purple line thing in the middle of the screen. And it just wouldn't go away.
Confused, I sent the following message to doc!, in hopes of enlightenment:
-----------------------------
So, I was about to use my camera to take a picture at Richard's house, but the camera was in video mode. When I hit the "record" button, I noticed a distinct purple line which cross-sectioned the view of the room, and it seemed to originate from a lamp. I moved around the camera a bit, and saw that if I rotated it enough, the purple line disappeared.
Could you point me in the right direction so I could blog about it?
thanks,
andrew
-----------------------------
and here was the response:
Interesting. It appears to be some kind of internal reflection in the lens of the camera caused by the high intensity of the light. I would guess that it as you move the camera up and down, the purple line will stay directly on the lamp. Does the line rotate as you rotate the camera? This is something like the star effects that cameras as sometimes designed to produce ... those are diffraction effects.
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as the video verifies, doc!'s hypothesis that the purple line would only disappear if the camera were moved side to side is correct. unfortunately, I failed to grasp very much understanding here. I googled 'star effect' and every single result seemed to be selling something.
For now, the phenomena is unresolved, both because I am stuck and because I have a lot to do tonight. I am annoyingly very confused, just like how I will be on tomorrow's physics test.
Monday, March 15, 2010
Contacts
Busy weekend, busy day, busy sunday night.. not much else needs to be said!
so here's a quickie:
From my time here at Iolani, I'd say that I've seen more people wearing glasses than anywhere else in my life. I can't really tell you why we all have bad eyesight, but I do too. But me, I wear contacts. Contact lenses. Something we've been studying about in physics.
Since you unsophisticated people wear glasses, today's lesson is about how to properly put on a contact. While each pair of contact lenses is lightweight, transparent, and looks the same oriented forward or backward, believe it or not there's a very specific way to put them on. First, hands gotta be clean and dry, but moist. Contacts must be inserted, concave side up. Otherwise, as us sophisticated guys know, very painful irritation occurs and vision is severely impaired.
The issue is, the irritation only kicks in moments after you put in the contacts. And your vision is always impaired when you put in the lens, but if done correctly, should cease after a minute. If the lens are inserted convex side up, vision is strangely enough, impaired forever. To the point where one can see better without having them on. But I digress....
So to give you an idea of what life was like, when I confused convex side with concave side:
I woke up, but didn't really wake up, and could barely pry my eyes open to get the contacts in..
I was late, and noticed that my eyes, still tired and closed felt like they were swelling on the way to school. I opened my eyes and realized I couldn't see a thing. Class was pretty fun, having to tap the person next to me to figure out what my teachers were writing on the board. And then Mr. Park put me on the spot, and I didn't even know what the question was...
If you mix up the sign, it's almost as fatal as forgetting a negative sign on object or image distance on a quiz. Almost.
so here's a quickie:
From my time here at Iolani, I'd say that I've seen more people wearing glasses than anywhere else in my life. I can't really tell you why we all have bad eyesight, but I do too. But me, I wear contacts. Contact lenses. Something we've been studying about in physics.
Since you unsophisticated people wear glasses, today's lesson is about how to properly put on a contact. While each pair of contact lenses is lightweight, transparent, and looks the same oriented forward or backward, believe it or not there's a very specific way to put them on. First, hands gotta be clean and dry, but moist. Contacts must be inserted, concave side up. Otherwise, as us sophisticated guys know, very painful irritation occurs and vision is severely impaired.
The issue is, the irritation only kicks in moments after you put in the contacts. And your vision is always impaired when you put in the lens, but if done correctly, should cease after a minute. If the lens are inserted convex side up, vision is strangely enough, impaired forever. To the point where one can see better without having them on. But I digress....
So to give you an idea of what life was like, when I confused convex side with concave side:
I woke up, but didn't really wake up, and could barely pry my eyes open to get the contacts in..
I was late, and noticed that my eyes, still tired and closed felt like they were swelling on the way to school. I opened my eyes and realized I couldn't see a thing. Class was pretty fun, having to tap the person next to me to figure out what my teachers were writing on the board. And then Mr. Park put me on the spot, and I didn't even know what the question was...
If you mix up the sign, it's almost as fatal as forgetting a negative sign on object or image distance on a quiz. Almost.
Monday, March 8, 2010
Is it good to be organized?; Seeing is not Believing!
To skip my midlife crisis, go past the dotted line!
Life has honestly become more and more of a mechanical grind. More than it ever has been, I think.
I wake up at a pre-determined time in the mornings, calculated precisely the night (or morning, hehe) before to account for leftover homework, head to school and finish it, and follow my generic schedule. After-school is pretty mechanical too. I have my schedules all planned out, for each day of the week. Mondays are scholarship, then doc!'s room. Tuesdays are cram for violin lesson. Wednesdays are violin lesson, and Thursdays are quartet. Well, you get the idea.
Even the stuff we learn is pretty mechanical. English will always be vocabulary, and analytical essays. Math will be.... math... and physics will be real world applications of math with lots of equations (kind of?)
So, I don't really know anymore. My friends, teachers, and family all seem to believe that being organized is a good thing. Especially after today, when I had a long talk with my dad about "having a sense of direction, of where I'm headed." I don't know though, if it's good to know everything about where I'm headed. Kind of takes the fun and thrill out of things, especially considering that I only get three more years to be a teenager.
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While pondering above thoughts, I had a water glass on my desk...
I quickly noticed an everyday example of refraction--the tendency of light to travel at different speeds through different mediums.
Light travels more quickly through air than it does through water. As a result, it creates a distorted image of a straw:
And here's some guy who saw the same thing I did, but with a straw, because that's normally what people have in water glasses. Comes with some analysis; which is cool, so I don't have to do any~.
So, although the straw appears to be bent from an overhead observer, the picture indicates that the 'real straw' is a continuation of the straw above the surface of the water, just like our brains would like to believe.
Life has honestly become more and more of a mechanical grind. More than it ever has been, I think.
I wake up at a pre-determined time in the mornings, calculated precisely the night (or morning, hehe) before to account for leftover homework, head to school and finish it, and follow my generic schedule. After-school is pretty mechanical too. I have my schedules all planned out, for each day of the week. Mondays are scholarship, then doc!'s room. Tuesdays are cram for violin lesson. Wednesdays are violin lesson, and Thursdays are quartet. Well, you get the idea.
Even the stuff we learn is pretty mechanical. English will always be vocabulary, and analytical essays. Math will be.... math... and physics will be real world applications of math with lots of equations (kind of?)
So, I don't really know anymore. My friends, teachers, and family all seem to believe that being organized is a good thing. Especially after today, when I had a long talk with my dad about "having a sense of direction, of where I'm headed." I don't know though, if it's good to know everything about where I'm headed. Kind of takes the fun and thrill out of things, especially considering that I only get three more years to be a teenager.
---------------------------------------------------------------------------------------------
While pondering above thoughts, I had a water glass on my desk...
I quickly noticed an everyday example of refraction--the tendency of light to travel at different speeds through different mediums.
Light travels more quickly through air than it does through water. As a result, it creates a distorted image of a straw:
And here's some guy who saw the same thing I did, but with a straw, because that's normally what people have in water glasses. Comes with some analysis; which is cool, so I don't have to do any~.
So, although the straw appears to be bent from an overhead observer, the picture indicates that the 'real straw' is a continuation of the straw above the surface of the water, just like our brains would like to believe.
Saturday, February 27, 2010
WANTED: Jason Preble, Destroyer of Magnets
I guess I've been aware of it all my life, but physics isn't always.. amazing. :[
Sometime during Saturday's performance, my precious magnet (see last week) was destroyed by a tumultuous force of nature. Our bassoonist, Jason Preble, haphazardly crushed my red, star-shaped clip.
Jason's force exerted by gravity (weight) is much greater than the magnet is able to handle. Assuming Jason's mass is about 60 kg, his weight would be about 600 Newtons. 600 Newtons divided by 4.184 Newtons per pound results in a weight about 143 pounds. Of course, it's no surprise then, that my magnet which weighs about six pounds, was brutally crushed.
Additionally, we can't forget about impulse: the product of force and time. Since we have already established that assuming Jason's foot came from straight above the magnet, impulse would simply be that number times the amount of time Jason took before realizing that he smashed my magnet and taking his foot off. I'd assume that this time is no more than maybe, half a second?
And then, there's the transfer of momentum from Jason's foot to my magnet. Since the magnet simply got crushed, without really moving much, the collision was clearly inelastic (kinetic energy is not conserved)
The mistake was of course understandable; after all, the pit area is always dark, and navigating through a sea of stands and instruments is difficult.
Sometime during Saturday's performance, my precious magnet (see last week) was destroyed by a tumultuous force of nature. Our bassoonist, Jason Preble, haphazardly crushed my red, star-shaped clip.
Jason's force exerted by gravity (weight) is much greater than the magnet is able to handle. Assuming Jason's mass is about 60 kg, his weight would be about 600 Newtons. 600 Newtons divided by 4.184 Newtons per pound results in a weight about 143 pounds. Of course, it's no surprise then, that my magnet which weighs about six pounds, was brutally crushed.
Additionally, we can't forget about impulse: the product of force and time. Since we have already established that assuming Jason's foot came from straight above the magnet, impulse would simply be that number times the amount of time Jason took before realizing that he smashed my magnet and taking his foot off. I'd assume that this time is no more than maybe, half a second?
And then, there's the transfer of momentum from Jason's foot to my magnet. Since the magnet simply got crushed, without really moving much, the collision was clearly inelastic (kinetic energy is not conserved)
The mistake was of course understandable; after all, the pit area is always dark, and navigating through a sea of stands and instruments is difficult.
Monday, February 22, 2010
Don't leave home without your magnet; Kiss me Kate to open in Five Days!
As far as things that needed to be done and time available for me to do said things goes, this was probably the worst week of the year. Frequent readers of this blog have informed me that I begin every single blog this way, but it's so true. You have to put up with me, readers, because this is always the first thing that comes to mind when I start writing on Sunday night.
On Saturday, the pit orchestra had a Sitzprobe five hour rehearsal, in which we played the same stupid music millions of times, for five hours. And the music is in itself, impossibly hard (or maybe just for us violins). And we played this impossibly hard music for, you guessed it, five hours. Probably one of the most memorable (worst) experiences of my life, actually...
also, why the hell is Hawaii Theatre in the middle of Chinatown? cmon, seriously?
After the rehearsal ended around five, I decided to relieve some stress (read:procrastinate) by heading over to Ka'kaako park with a friend. The area itself is always hilly, almost always windy, and almost always a place with noone around. Of course, my friend had to lose her stupid keys at some point, with hills everywhere and nobody else around. So we spent a fair amount of time looking for a tiny gold thing in a probable three acre area, like a needle in a haystack [cliche, i know, sue me!]
so we searched for a while, of course with me chastising about not putting a string thing around the keyring like i do with mine.
I of course, came up with the brilliant idea of using the clip I used to hold my kiss me kate music together to find the keys. The catch is, that it doubles up as a magnet! Because keys are a metal, and magnets immediately feel an attractive force towards metals (which contain 'a sea of electrons' throughout), I was able to search much more efficiently by just running my magnet around the long grass (as opposed to moving it around with my hands). Soon the keys turned up!
I, of course, have no idea why I have a Hawaii State Teacher's Association magnet-clip, but it sure was awesome at the time.
had i left my house without this ridiculous clip, or had i forgotten about the awesome power of magnets, i may have been looking and annoyed for a very long time.
don't leave home without a magnet, kids!
On Saturday, the pit orchestra had a Sitzprobe five hour rehearsal, in which we played the same stupid music millions of times, for five hours. And the music is in itself, impossibly hard (or maybe just for us violins). And we played this impossibly hard music for, you guessed it, five hours. Probably one of the most memorable (worst) experiences of my life, actually...
also, why the hell is Hawaii Theatre in the middle of Chinatown? cmon, seriously?
After the rehearsal ended around five, I decided to relieve some stress (read:procrastinate) by heading over to Ka'kaako park with a friend. The area itself is always hilly, almost always windy, and almost always a place with noone around. Of course, my friend had to lose her stupid keys at some point, with hills everywhere and nobody else around. So we spent a fair amount of time looking for a tiny gold thing in a probable three acre area, like a needle in a haystack [cliche, i know, sue me!]
so we searched for a while, of course with me chastising about not putting a string thing around the keyring like i do with mine.
I of course, came up with the brilliant idea of using the clip I used to hold my kiss me kate music together to find the keys. The catch is, that it doubles up as a magnet! Because keys are a metal, and magnets immediately feel an attractive force towards metals (which contain 'a sea of electrons' throughout), I was able to search much more efficiently by just running my magnet around the long grass (as opposed to moving it around with my hands). Soon the keys turned up!
I, of course, have no idea why I have a Hawaii State Teacher's Association magnet-clip, but it sure was awesome at the time.
had i left my house without this ridiculous clip, or had i forgotten about the awesome power of magnets, i may have been looking and annoyed for a very long time.
don't leave home without a magnet, kids!
Monday, February 8, 2010
Gravitational Potential Energy: An Episode from the Past!
Today, I made some new friends at Richard's house. And I just love introducing new friends to people! But I don't have names for them (yet).
For the last couple of weeks during our study of electrostatics, a key to many problems is calculating electric potential and electric potential energy (there IS a distinction between the two!). Conceptually, doc! used the model of gravitational potential energy to help explain electric potential, as the two are actually quite similar.
While finding homes for my new friends, I discovered that some habitats were at greater heights than others. Since gravitational potential energy equals mass times acceleration due to gravity times height, the habitats located higher on the storage bin should have a greater potential energy, right?
To take a page from the writers of the AP Physics B book, this blog will have a "Gotchas" section (which doc! never makes us read, but it's fun to, anyway). Because I forgot to mass each of my friends and measure the actual heights of each level of the storage bin, calculating gravitational potential energy is impossible. Ranking the gravitational potential energies is hence, also impossible.
While usually a higher elevation results in a greater potential energy, we cannot assume that the highest potential energy habitat is at the very top without making our own hypotheses about the masses and heights of Hamtaro, Dog, and Bear. For example, Hamtaro is the highest, but probably has the lowest mass. M will be a smaller value than for the other friends, but H will be a larger value. The same dilemma holds for dog and bear; we can only generalize about whether M and H are greater or lesser in correlation with the other friends.
The only thing we can say for sure, is that the potential energy of Mr. Killer Whale is zero, because he is at a height of zero: mass times acceleration of gravity times zero equals zero, regardless of what the other numbers are.
Sunday, January 31, 2010
Insulators
Electricity, indeed, is an abstract topic; to read about, understand, and especially blog about. Physics has definitely gotten more challenging, "kicked up a notch," and the added time pressure on tests isn't too helpful, either. But I can't help but feel exicted, too. One more semester from junior year, and i'm done forever. wheeeeee!
Recall from last week that an insulator resists the flow of energy, most commonly either heat or electrical. However, the American Heritage Dictionary also defines an 'insulator' as more generally, something that segregates from and/or prevents from happening. Am I allowed to say that this blog is 'insulating' me from doing my APUSH research proposal? Someone tell me!
In general, insulators and conductors are dichotomous--any object is either one or the other. Just like conductors, an average household is filled with insulators! Here's some that I believe every household should have:
wood (paper is made from wood, sort of)
glass
rubber (so then, what happens when you flip an electric switch with wet, rubber gloves on? someone try and let me know the results)*
now, onto the six pages of my research proposal, which is going to be twice as long as the actual paper itself. see you next week, yo!
* (asterisk denotes that author reserves the right to clarify and will not be subject to any incidents of pain and suffering and/or will not be liable for any accidents that may occur)
Recall from last week that an insulator resists the flow of energy, most commonly either heat or electrical. However, the American Heritage Dictionary also defines an 'insulator' as more generally, something that segregates from and/or prevents from happening. Am I allowed to say that this blog is 'insulating' me from doing my APUSH research proposal? Someone tell me!
In general, insulators and conductors are dichotomous--any object is either one or the other. Just like conductors, an average household is filled with insulators! Here's some that I believe every household should have:
wood (paper is made from wood, sort of)
glass
rubber (so then, what happens when you flip an electric switch with wet, rubber gloves on? someone try and let me know the results)*
now, onto the six pages of my research proposal, which is going to be twice as long as the actual paper itself. see you next week, yo!
* (asterisk denotes that author reserves the right to clarify and will not be subject to any incidents of pain and suffering and/or will not be liable for any accidents that may occur)
Sunday, January 24, 2010
Conductors
It's really kind of annoying when the physics test that everyone thought was easy, in (including yourself), in fact, so easy that doc decides to pull off the curve, turns out to be your worst test in second quarter, actually perhaps in the whole year. /sigh; oh well!
In class, we've moved from thermodynamics to electricity, which means a bunch of new stuff, and hopefully (for me) a better test. I did notice that just like how there are thermal conductors, there are electrical conductors. The same, of course, goes for insulators.
In both cases, an insulator resists the flow of energy, either heat or electrical energy. A conductor, then, allows the transfer of energy. This week's focus is on a couple things I could find in my house that are appropriate conductors of heat and electricity (there are a lot more than I thought!).
the wiring system which hooks up my router/road runner
alt=""id="BLOGGER_PHOTO_ID_5430483590652937122" />
no idea why that bandaid was there..
so why are cooking things made out of metal? you tell me!
Some observations:
-any kind of metal is a good conductor.
-any kind of wiring is extremely good, too.
-water is a great electrical conductor but a terrible heat conductor. hmmmm....
With this, we know why parents always nag about drying your hands before turning off the light switch in the bathroom. See you next week for insulators.
In class, we've moved from thermodynamics to electricity, which means a bunch of new stuff, and hopefully (for me) a better test. I did notice that just like how there are thermal conductors, there are electrical conductors. The same, of course, goes for insulators.
In both cases, an insulator resists the flow of energy, either heat or electrical energy. A conductor, then, allows the transfer of energy. This week's focus is on a couple things I could find in my house that are appropriate conductors of heat and electricity (there are a lot more than I thought!).
the wiring system which hooks up my router/road runner
alt=""id="BLOGGER_PHOTO_ID_5430483590652937122" />no idea why that bandaid was there..
so why are cooking things made out of metal? you tell me!
Some observations:
-any kind of metal is a good conductor.
-any kind of wiring is extremely good, too.
-water is a great electrical conductor but a terrible heat conductor. hmmmm....
With this, we know why parents always nag about drying your hands before turning off the light switch in the bathroom. See you next week for insulators.
Monday, January 18, 2010
Thoughts on Finals, Does anyone use CDs anymore? The Future of Google in China?
January 17, 2010
A few blogs into the New Year. Feeling pretty good. Finals are over. APUSH is over, which effectively doubles my free time.
Hell yeah!
We should all take some time to thank Doc, the heavens, and whoever else lent a hand in eliminating the semester AP Physics B exam. I literally got under two hours of sleep on some nights, which is just not fun. An additional exam, especially physics, might just have made me want to kill myself just the same, but a lot more.
I always try my best to give credit where it is due. This week, that means putting my trusty Sansa MP3 in the spotlight, for being my best friend in these times of crises, and getting me through it all. This being, of course, the same one I got for Christmas and generally carry EVERYWHERE:
Of course, I need to keep my 'best friend' updated with the latest music and sound clips. Most of the time, I get the music burned on a CD and download it to my computer, from which I can transfer directly to the Sansa. Takes less than 30 seconds to upload the entire CD!
But I guess the irony of it all, in this day and age, is that CDs have gone through Napoleon status: from towering heights of popularity to completely obsolete. The CDs I use were all ones that I had from before, but never listened to, because, well, they were CDs. Last Thursday, my friend sent me a playlist from a Rise Against album which I just couldn't resist picking up. I decided, then, to take a blast into the past (cliche much!) and burn it on a CD, and listen to it that way, for nostalgia's sake. I had to borrow my dad's coworker's CD player to use it, though, since really, who the hell uses CDs anymore? (did I say this already?) I forgot to grab an actual picture, but it looks something like this:
I noticed that after the initial time it took for the CD to get going, it spun around on the player in uniform circular motion, just like we studied in November. The radius of a standard CD is 6.05 cm, or 0.0605m, and the mass of a standard CD is 14.4g or 0.0144 kg. Knowing these two meaningless facts, we can find a lot more meaningless things!
A Review on Rotation formulae:
Radial/Centripetal acceleration is equal to velocity squared divided by radius. Since Newton discovered that Force equals mass times acceleration, Centripetal force equals mass times velocity squared, all divided by the radius.
Furthermore, if I calculated the period of one rotation, I could calculate tangential and angular acceleration, too. This can be done with the formula, Tangential Velocity equals (2pi)(radius)/(period). Angular acceleration equals simply (2pi)/(period).
We also did a chapter on rotational kinematics/dynamics and studied about angular velocity, angular acceleration, and angular displacement. Given angular velocity, we can figure out so many more meaningless things about my CD on a CD player.
Now, I'm not going to calculate all of those things, because it is 12:31 A.M., but feel free to do it if you want to! I'm off to do my problem set, which looks inherently difficult. . .
In other news, Google has gone down the tubes in China, I guess. Baidu stock at an all time high, as of 8 hours ago!
A few blogs into the New Year. Feeling pretty good. Finals are over. APUSH is over, which effectively doubles my free time.
Hell yeah!
We should all take some time to thank Doc, the heavens, and whoever else lent a hand in eliminating the semester AP Physics B exam. I literally got under two hours of sleep on some nights, which is just not fun. An additional exam, especially physics, might just have made me want to kill myself just the same, but a lot more.
I always try my best to give credit where it is due. This week, that means putting my trusty Sansa MP3 in the spotlight, for being my best friend in these times of crises, and getting me through it all. This being, of course, the same one I got for Christmas and generally carry EVERYWHERE:
Of course, I need to keep my 'best friend' updated with the latest music and sound clips. Most of the time, I get the music burned on a CD and download it to my computer, from which I can transfer directly to the Sansa. Takes less than 30 seconds to upload the entire CD!
But I guess the irony of it all, in this day and age, is that CDs have gone through Napoleon status: from towering heights of popularity to completely obsolete. The CDs I use were all ones that I had from before, but never listened to, because, well, they were CDs. Last Thursday, my friend sent me a playlist from a Rise Against album which I just couldn't resist picking up. I decided, then, to take a blast into the past (cliche much!) and burn it on a CD, and listen to it that way, for nostalgia's sake. I had to borrow my dad's coworker's CD player to use it, though, since really, who the hell uses CDs anymore? (did I say this already?) I forgot to grab an actual picture, but it looks something like this:
I noticed that after the initial time it took for the CD to get going, it spun around on the player in uniform circular motion, just like we studied in November. The radius of a standard CD is 6.05 cm, or 0.0605m, and the mass of a standard CD is 14.4g or 0.0144 kg. Knowing these two meaningless facts, we can find a lot more meaningless things!
A Review on Rotation formulae:
Radial/Centripetal acceleration is equal to velocity squared divided by radius. Since Newton discovered that Force equals mass times acceleration, Centripetal force equals mass times velocity squared, all divided by the radius.
Furthermore, if I calculated the period of one rotation, I could calculate tangential and angular acceleration, too. This can be done with the formula, Tangential Velocity equals (2pi)(radius)/(period). Angular acceleration equals simply (2pi)/(period).
We also did a chapter on rotational kinematics/dynamics and studied about angular velocity, angular acceleration, and angular displacement. Given angular velocity, we can figure out so many more meaningless things about my CD on a CD player.
Now, I'm not going to calculate all of those things, because it is 12:31 A.M., but feel free to do it if you want to! I'm off to do my problem set, which looks inherently difficult. . .
In other news, Google has gone down the tubes in China, I guess. Baidu stock at an all time high, as of 8 hours ago!
Sunday, January 10, 2010
Who Really Cares about Sleep, The Internal Energy of Compressed Air
This Thursday and Friday are finals. Tonight's the last weekend night I'll have to study for them. Oh my god!
Sleep has been really tough on me, I guess. But more or less, I've gotten used to it. I no longer need to panic when I still have a million things to do, and it's ten or eleven P.M. And my parents, my loving parents, do tend to understand. They don't really bother me anymore, understanding that Iolani is really unforgiving as far as homework goes. And me, sinister ol' me, still spends substantial amounts of time while 'doing homework' talking to friends and not being productive. Food for next year's New Year's Resolutions, I guess.
------------------------------------------------------------------------------
Today is Sunday, and I decided to crack open my desktop PC (literally) to clean the inside. I went to Walmart and bought a can of compressed air to remove damage-causing dusts and lints in inaccessible areas. The last time I did this was years ago, so the dust buildup was tremendous. I had to use the entire can! With 20% more! (thanks, Walmart)
Towards the end of the can's life, I noticed that it got extremely cold to the touch. I thought about it, and initially assumed that it was an application of the Ideal Gas Law. Since pressing the valve and releasing air reduced overall pressure in the can of compressed air, temperature should consequently decrease, because pressure and temperature are proportional:
PV = nRT (can)
R and n remain constant. Hence, PV = T; Pressure and Volume are directly proportional to Temperature.
Fair enough. But then, I read the fine print on my CleanSafe can, which indicated that less than 5% of the product was actually gas; the name "compressed air" is misleading in that most of the product (the other 95%) is actually stored as a liquid at an extremely low temperature. What we need is an equation that applies to both gases and liquids.
Upon doing some further research, the answer appears to be the Joule-Thomson effect, something we haven't learned yet. But here's the Wikipedia definition:
"In thermodynamics, the Joule–Thomson effect or Joule–Kelvin effect or Kelvin–Joule effect describes the temperature change of a gas or liquid when it is forced through a valve or porous plug while kept insulated so that no heat is exchanged with the environment.[1][2][3] This procedure is called a throttling process or Joule–Thomson process.[4] At room temperature, all gases except hydrogen, helium and neon cool upon expansion by the Joule–Thomson process.[5][6]"
I'm not going to publish this as some sort of discovery, because I don't expect to be right on the money. In fact, I may be completely off the mark. But here's my interpretation of it (in English!)
Fluid exits the valves and is accelerated. Since energy is conserved, the additional KE must come from somewhere. "Somewhere" is the internal energy of the gas. Internal energy is directly related to temperature, as we've learned in class.
Hence, the accelerated gas will have a lower internal energy than the canister gas and will therefore have a lower temperature. That's why upon usage of the can, compressed air eventually feels extremely cold.
I feel like a SCIENTIST! (Someone tell me, please, if I'm completely wrong, so I can change this blog)
plus, I look kind of creepy. especially if you enlarge the photo :[
Sleep has been really tough on me, I guess. But more or less, I've gotten used to it. I no longer need to panic when I still have a million things to do, and it's ten or eleven P.M. And my parents, my loving parents, do tend to understand. They don't really bother me anymore, understanding that Iolani is really unforgiving as far as homework goes. And me, sinister ol' me, still spends substantial amounts of time while 'doing homework' talking to friends and not being productive. Food for next year's New Year's Resolutions, I guess.
------------------------------------------------------------------------------
Today is Sunday, and I decided to crack open my desktop PC (literally) to clean the inside. I went to Walmart and bought a can of compressed air to remove damage-causing dusts and lints in inaccessible areas. The last time I did this was years ago, so the dust buildup was tremendous. I had to use the entire can! With 20% more! (thanks, Walmart)
Towards the end of the can's life, I noticed that it got extremely cold to the touch. I thought about it, and initially assumed that it was an application of the Ideal Gas Law. Since pressing the valve and releasing air reduced overall pressure in the can of compressed air, temperature should consequently decrease, because pressure and temperature are proportional:
PV = nRT (can)
R and n remain constant. Hence, PV = T; Pressure and Volume are directly proportional to Temperature.
Fair enough. But then, I read the fine print on my CleanSafe can, which indicated that less than 5% of the product was actually gas; the name "compressed air" is misleading in that most of the product (the other 95%) is actually stored as a liquid at an extremely low temperature. What we need is an equation that applies to both gases and liquids.
Upon doing some further research, the answer appears to be the Joule-Thomson effect, something we haven't learned yet. But here's the Wikipedia definition:
"In thermodynamics, the Joule–Thomson effect or Joule–Kelvin effect or Kelvin–Joule effect describes the temperature change of a gas or liquid when it is forced through a valve or porous plug while kept insulated so that no heat is exchanged with the environment.[1][2][3] This procedure is called a throttling process or Joule–Thomson process.[4] At room temperature, all gases except hydrogen, helium and neon cool upon expansion by the Joule–Thomson process.[5][6]"
I'm not going to publish this as some sort of discovery, because I don't expect to be right on the money. In fact, I may be completely off the mark. But here's my interpretation of it (in English!)
Fluid exits the valves and is accelerated. Since energy is conserved, the additional KE must come from somewhere. "Somewhere" is the internal energy of the gas. Internal energy is directly related to temperature, as we've learned in class.
Hence, the accelerated gas will have a lower internal energy than the canister gas and will therefore have a lower temperature. That's why upon usage of the can, compressed air eventually feels extremely cold.
I feel like a SCIENTIST! (Someone tell me, please, if I'm completely wrong, so I can change this blog)
plus, I look kind of creepy. especially if you enlarge the photo :[
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