Question

A car with a hanging mass attached to the ceiling starts from rest up a hill and the driver never presses on the gas or the brakes. Once reaching the bottom of the hill the road levels out horizontally for a short distance then curves around a flat 30-m-radius circular path. While the car is rounding the curve the hanging mass makes an angle of 30˚ with respect to the vertical. Assume no energy is lost to friction.

(a) What height must the car have started from?

(b) Use one of the sense-making techniques to analyze your solution to part (a). Clearly state which technique you’re using and why it is relevant.

Answer 1