cant really answer here with text but at the top of the slide it should br positives and towards the bottom its negative.
This is because you go faster at the top of the slide than the bottom and when your at the bottom you slow down
This depends on it's current position. If the ball is at rest on the surface of Earth, then there will be just the force of both Gravity and the contact force preventing it from crushing through the ground. However. If the ball is in motion then other forces maybe present such as Air Resistance and Friction.
1. C- 446
2. A- 778
3. B- 400
4. A- 11