A roller coaster starts from rest at point a and continues to point b on a frictionless track. what best describes the changes in kinetic and potential energy as the car travels from point a to point b?

Verified Answer :

At first when the car is at the datum
point where is no elevation, the kinetic energy increases while the potential
energy is zero. As it travel the path and goes upward the kinetic enrgy
decreases while the potential energy increases. When it goes down again the
kinetic enrgy increases again while the potential energy decreases 

Took a wild guess and got it correct. The answer is B Kinetic Energy increases and potential energy decreases.