A particle of mass m is projected from point A with an initial velocity V0 perpendicular to line OA and moves under a central force F along a semicircular path of diameter OA. Observing that r0cos ?=r and using mr^2d?/dt=angular momentum, show that the speed of the particle is v=v0/cos^2(?). Given this find the tangential components of the central force along the tangent to the path of the particle at (a) theta=0 and (b) theta=45degrees.