WILL GIVE A toy rocket of mass 12kg is launched upwards with an initial velocity of 3m/s. Use conservation of energy to determine how high it flies.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.