A medical imaging device shoots 8 million electrons per second through an Ohmic gas. The electrons are motivated by a 3000 V potential difference. What is the effective resistance of the gas?

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.