A mass m is dropped from rest at a height h above the ground. It experiences both a gravity force of magnitude mg and a drag force with magnitude cln(V2), where V is the speed of the mass and c is a constant. What is the terminal velocity of the falling mass ('terminal velocity' is the velocity that the particle will approach if it continues to fall for an infinitely long time)

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.