A+ Answers

An unknown planet has a mass of 7 x 10^31 kg and a diameter of 5 x 10 ^10m. Mark has a mass of 70kg and is on the surface of the planet.

1.Prove that the magnitude of the gravitational acceleration on the planet is 7.5ms^-2

 2. Mark throws a ball vertically
upwards at 2.6ms^-1 from a height 80 cm. Choose upwards as positive. Ignore air resistance and calculate the maximum height that the ball reaches.

3. The ball falls back to the ground and bounces once before Mark catches it at the original height of 80 cm. Draw a neat position-time graph for the motion of the ball. Only fill in the values of position on the graph.