# In the figure, a frictionless roller coaster car of mass m = 805 kg tops the first hill with speed vi = 18 m/s at height h = 41 m. What is the speed of the car at (a) point A, (b) point B, and (c) point C? (d) How high will the car go on the last hill ?

##### 1 Answer

(a) At point A

(b) At point B

(c) At Point C

(d)

#### Explanation:

The problem is about Conservation of Energy, between Potential Energy and Kinetic energy changes.

Given is friction-less roller coaster. it is also assumed that there is no loss of energy due to air friction.

Given also is that initial velocity is towards the

Therefore, at any location

Inspection reveals that

Initial

Considering only the

(a) At point A. The situation is same as at

(b) At point B. Height is

*y* direction only

(c) At Point C. Here all the initial

Following similar steps as in for point B. above,

(d) At the last hill. Car can go only up to initial height