Question

rite the formula for Newton’s universal law of gravity, explaining all terms used. [2 marks] (b) Explain what is meant by centripetal force. [2 marks] (c) Derive a formula for the relationship between the period of a satellite and the radius of its orbit. [4 marks] (d) The moon Triton orbits the planet Neptune every 5.88 days with an orbital radius of 3.55×105 km. Although Neptune is a gas giant we can still identify a “surface” at a distance of 2.48×104 km from the centre. (i) Calculate the mass of Neptune. [4 marks] (ii) Calculate the average density of Neptune. [3 marks] (iii) The tiny inner moon Naiad orbits Neptune in just 423 minutes. Determine how close this is to the planet’s surface.

Answer 1