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.