3. A cart at rest at the top of a roller coaster has 1000 J of
potential energy. The roller coaster goes down one hill and up
another smaller hill. If it has 400 J of potential energy at the
top of the second hill, how much kinetic energy does it have?
A)OJ B) 250 J
C) 600J
D) 1400 J E) 400000 J

600J

Explanation:

Assuming no energy is lost and perfect transfers.

On the top of the first hill, - however there is no Kinetic Energy so -

On the second hill, the total amount of energy is still the same (1000) - this time we have a smaller amount of potential energy. We can rearrange to get

the part of the wave he is travelling on is the crest