Which of these describes the use of hieroglyphics and pictographs in ancient times? Select all correct answers. a. They were often drawn on walls
b. They were made using modern art tools
c. They record events and cultural histories
d. They are a form of signal that can be heard.
Explain your answer.

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.