As ocean waves get closer to the shore they slow down. this slowing causes them to bend and come in close to parallel with the shore. this is because shallow water and deep water can be thought of as two different media. this bending of a wave is the wave interaction known as

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.