Rod OA rotates about O in a horizontal plane. The motion of the 300g collar B is defined by the relations r = 300+100 cos(0.5) and 0 = (12-31), where r is Ꮎ expressed in millimeters, t in seconds, and in radians. Determine the radial and transverse components of the force exerted on the collar when (a) t=0, (b) t=0.5s.