A 50 kg man stands on the surface of a frozen pond. In order to get to the side of the pond he throws his 1 kg shoes at a speed of 10 m/s. After that what’s the speed of the man? ( neglect all frictions)

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.