Question

A 650 kg roller coaster car has two points of reference given to an observer. Point A, at a height of 120 m, the cart is moving at 3.40 m/s. Later on in the ride, at point B, the cart is moving at 28.2 m/s. Determine the height at point B.

None of the formulas on my formula sheet are helping me with this one.

Answer 1

I think all I need to do is do

B Height = A Height x A Speed over B Speed

But that seems too simple.

Answer 2

Energy relations:
initial total energy=final total energy
This assume zero friction on the roller coaster, a very silly assumption.

1/2*m*3.4^2+m*9.8*120=1/2 m*28.2^2 + mg*final height
find final height.

Answer 3

Your simple solution is way off target in our real world.

Answer 4

Thank you. By the way, there is question is assuming there is no friction, so this helps a lot.

Thank you so much.