A ball is released onto a horizontal surface and rebounds straight upwards. While the ball is touching the ground, the following forces are acting: • the weight $W$ of the ball • the contact force $P$ applied to the ground by the ball • the contact force $N$ applied to the ball by the ground. At the moment the ball is in contact with the ground, it is instantaneously at rest. At this instant, which relationship is correct?
- A$N = P + W$
- B$N > P + W$
- C$N = W$
- D$N > W$