A motor is used to raise a lift of mass 200 and 4 passengers each of whom has an average mass of 65 kg. They wish to go to the third floor, which is 12 m above them, If the motor is 45% efficient, what input of electrical energy is required? Give your answer in kJ (Show Work)

In a game of pool, ball a is moving with a velocity v0 of magnitude v0 = 15 ft/s when it strikes balls b and c, which are at rest and aligned as shown. knowing that after the collision the three balls move in the directions indicated and assuming frictionless surfaces and perfectly elastic impact (that is, conservation of energy), determine the magnitudes of the velocities va, vb, and vc.