OP 2a za Four identical masses (each size m) are attached to the corners of a square frame of dimensions 2a x 2a. The frame is of negligible mass. Initially the system rotates in its plane with = w, with the CM at rest. We briefly fire a rocket thrusters in to the page at corner B, endowing the system with momentum -P2. As it happens, P = 2mwa. (a) Find the new angular momentum L (relative to an origin at the CM) and spin , expressed in the , , 2 basis. (b) Find the velocities of each of the four masses just after the thrust, and verify that the total momentum is -P2. (c) Find the kinetic energy of the system. (d) How long will it take before the square again lies in an &- plane (granted, at a new z).