A Level Physics Session

Gravitation Waves and Interference Magnetic Force Photoelectric Effect


Hi Everyone,

Welcome to this session on gravitation. The following are two videos on this topic.

090 Newton's law of gravitation

091 Gravitational field strength


Please try these questions.

  1. Suppose that a satellite always stays directly above the same spot on Earth’s equator. Find the period of revolution of the satellite in SI units.

  2. Find its angular velocity.

  3. Using GMm/r² and mω²r, write down an equation relating the gravitational and centripetal forces on the satellite. Explain.

  4. Rearrange this equation to make r the subject.

  5. Find r. Find the height of the satellite above the equation. Mass of Earth is 5.97x1024 kg.

  6. How many times is this distance bigger than the 6380 km radius of the Earth.

  7. What is the name of this type of satellite?

Past Exam Questions

In this video, I shall go through some questions from a past exam paper.

2012 H2 Physics P1 13

2012 H2 Physics P1 14

Thanks for attending this session.

Dr Hock
4 May 2014