A ball is thrown horizontally from the top of a building 120 m high. The ball strikes the ground 69 m horizontally from the
point of release. What is the speed of the ball just before it
strikes the ground?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.