A roller-coaster car with a mass of 1700 kg starts at rest from point A, 25.0 m above the ground. At point B, it is 7.00 m above the ground. If the work done against friction between point A and B is 21000 J (21.0 kJ), what is the kinetic energy of the car at point B in kJ? (Use g = 10 for the acceleration due to gravity). (note that 1 kilojoule or kJ = 1,000 J) K = KJ What is the magnitude of the velocity of the roller-coaster at point B? v = m/s