On the open seas, a cannonball is shot from a cannon at 12 m/s at an angle of 35° above horizontal. It leaves the cannon on the ships deck 4 m above the ocean
and lands on another ship's deck 2 m above the ocean.

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.