With what minimum speed must you toss a 200 g ball straight up to just touch the 15-m-high roof of the gymnasium if you release the ball 1.6 m above the ground? solve this problem using energy.

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.