You work hard to pedal your bicycle up a steep hill. You rest when you get to the top, then you let your bicycle roll quickly down the other side of the hill. You converted energy into energy, then you converted it back into energy.

Question

You work hard to pedal your bicycle up a steep hill. You rest when you get to the top, then you let your bicycle roll quickly down the other side of the hill. You converted ________ energy into ________ energy, then you converted it back into ________ energy.