Gravitational fields and Newton's law of gravitationEdexcel A-Level Physics: Mind map

Exam questions on Gravitational fields and Newton's law of gravitation

1. A mission planner is comparing the gravitational field of Mars with that of the Earth before designing a rover. Mars may be treated as a uniform sphere of mass 6.42×10²³ kg and radius 3.39×10⁶ m. The gravitational constant is G = 6.67×10⁻¹¹ N m² kg⁻².
   A rover of mass 185 kg is on the surface of Mars. Calculate the gravitational force on the rover.2 marks
2. A communications satellite of mass 850 kg moves in a circular path at a distance of 4.22×10⁷ m from the centre of the Earth. The Earth may be treated as a point mass of 5.97×10²⁴ kg at its centre.
   Calculate the gravitational field strength of the Earth at the position of the satellite.2 marks
3. A lunar lander is travelling along the straight line joining the centres of the Earth and the Moon. The mass of the Earth is 5.97×10²⁴ kg, the mass of the Moon is 7.35×10²² kg, the radius of the Moon is 1.74×10⁶ m and the distance between their centres is 3.84×10⁸ m. Take G = 6.67×10⁻¹¹ N m² kg⁻².
   Show that the gravitational field strength at the surface of the Moon is about 1.6 N kg⁻¹.3 marks