# Physics

posted by
**Tammy**
.

A roller coaster car of mass 1000kg is riding along a track from point A to point C. (point A is 75m high, B is 50m high and C is 100m high, so that there are a total of three hills.) the final velocity at point C is 10m/s

a) Assume no friction what is the speed of the car at the top of hill A?

intial = final

1/2mv_a^2 +mgh_a = 1/2mv_c^2 + mgh_c

1/2V_a^2 + 735 = 1048.02

V_a = 25 m/s

b) what is the max speed the car can achieve along the track? If the speed at point B is 33.2m/s.

What would be the equation for this part of the problem?

c) assume the car starts with the same speed as a) and there is friction present. The car does 50000J of work while the car moves from A to C, will the car still be able to ascend to the top of hill C? At what speed is the car at the top of C?

W= change in KE

and I got V_c = 26.5m/s