DUE TONIGHT 50 POINTS An applied force of 13 N east acts on a 6.5-kg block that is moving east at 2.5 m/s on a level, frictionless surface. What is the final speed
of the block if the force is applied for 2.1 s?
A. 1.7 m/s
B. 4.2 m/s
C. 6.7 m/s
D. 7.2 m/s

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.