Halliday, Resnick & Walker — Potential Energy and Conservation of Energy: Problem 9

9 In Problem 2, 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, which is too high for it to cross? (e) If we substituted a second car with twice the mass, what then are the answers to parts (a) through (d)? Context from Problem 2: In Fig. 8-18, a single frictionless roller-coaster car of mass \( m = 825 \text{ kg} \) tops the first hill with speed \( v_0 = 20.0 \text{ m/s} \) at height \( h = 50.0 \text{ m} \). Point A is at height \( h \), point B is at height \( h/2 \), and point C is at height \( 0 \). The gravitational potential energy is zero at C.