A solid sphere starts from rest at the top of an incline of height h and length l, and moves down. The force of friction between the sphere and the incline is F. This is insufficient to prevent slipping. The kinetic energy of the sphere at the bottom of the incline is W.
(a) The work done against the force of friction is Fl.
(b) The heat produced is Fl.
(c) W = mgh - Fl
(d) W > (mgh - Fl)
