Two technicians are discussing valve body checks. Technician A says a test for a sticky valve is to make sure that the all valves will free fall out of its bore. Technician B says that an aluminum valve can be checked by seeing how much side clearance it has by trying to wiggle it in its bore. Which technician is correct?a. Tech A
b. Tech B
c. Both A and B
d. Neither A nor B

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.