posted by robbie .
at the top of a hill a rollercoaster has 67,500j of kinectic energy and 290,000j of potential energy. gradually the rollercoaster comes to a stop due to friction. If the rollercoaster has 30,000j of potential energy when it stops, how much heat energy is generated by friction from the top of the hill until it stops?
Please put the correct school subject for the correct volunteer teacher! It is NOT 9th grade.