A particle C can move along a slide placed in a vertical plane. Points A and B are at the same horizontal level. Determine with respect to B the point where the velocity of C is zero for the first time in the three following cases:
a) C is released from A without initial velocity (Neglect friction).
b) C is launched downward from A along the slide (Neglect Friction).
c) C is released from A without initial velocity but is subjected to a frictional force.