Consider a rigid 3-mass system (with origin at the leftmost mass 3 M) which can rotate about an axis perpendicular to the system. The masses are separated by massless rods of length L so that the entire length is 2 L. 3 M 1 M 5 M L L x Find the x-coordinate of the center of mass for the three-mass system with respect to the origin. Treat the masses as particles.

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.