A43-n crate is suspended from the left end of a plank. the plank weighs 21 n, but it is not uniform, so its center of gravity does not lie halfway between the two ends. the system is balanced by a support that is 0.30 m from the left end of the plank. how far to the right of the support is the plank

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.