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Can you explain and tell me what the theory is called when a ball apears to be rolling up hill
Question Date: 2005-01-09
Answer 1:

Are you asking about how a ball would actually rolls uphill? Or are you asking about some optical illusion, where it's not really rolling uphill? I'm not sure what you mean, but I'll explain how a ball could actually roll uphill.

If my answer is not what you're looking for, please write me back and explain more what you're looking for.

A ball could have two different types of energy: kinetic energy or potential energy. Kinetic energy is the energy of motion. If the ball is moving, it has kinetic energy. Potential energy is stored energy, waiting to be used. If a ball is really high, it will have a lot of potential energy.

Picture two hills side by side, with a valley in the middle ,making a "U" shape. If you place a ball on the top of the left hill, it is high up, so it has potential energy. Now, if you allow it to roll down the hill, it changes that potential energy into kinetic energy (it gets less high and starts to roll faster). At the bottom of the "U", all of the potential energy has been converted to kinetic energy. As the ball continues to roll, and roll uphill on the right hill, it is converting that kinetic energy back into potential energy again.

So a ball must have kinetic energy to roll uphill. A ball that's not moving won't just start rolling uphill on its own. It doesn't have the energy. But a moving ball has kinetic energy, and can roll uphill for a while.

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