This diagram shows the variation of the Earth's gravitational field strength with distance from its centre. Determine the gravitational field strength at a height equal to 2 R above the Earth's surface, where R is the radius of the Earth.

According to graph gravitational field strength g is maximum on the surface of earth. ∵ Earth gravitational field g = G M R 2 ∴ g at height equal to 2 R = G M 3 R 2 = G M 9 R 2 = g 9 .

This diagram shows the variation of the Earth's gravitational field strength with distance from its centre. A satellite is put into an orbit at this height. State the centripetal acceleration of the satellite.

According to graph gravitational field strength g is maximum on the surface of earth. ∵ Earth gravitational field g = G M R 2 ∴ g at height equal to 2 R = G M 3 R 2 = G M 9 R 2 = g 9 . For centripetal acceleration of satellite on height 2 R from the surface of earth is equal to gravitational acceleration. ∴ a = g 9 .

MEDIUM

AS and A Level

IMPORTANT

Earn 100

This diagram shows the gravitational potential near a planet of mass M and radius R.

On a copy of the diagram, draw similar curves. For a planet of the same radius but of radius $2 R -$ label this ii.

Important Questions on Gravitational Fields

MEDIUM

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 17 - Gravitational Fields>EXAM-STYLE QUESTIONS>Q 11

Use the graphs to explain from which of these three planets it would require the least energy to escape.

HARD

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 17 - Gravitational Fields>EXAM-STYLE QUESTIONS>Q 11

Venus has a diameter of

12 100 km

and a mass of

4.87 \times 10^{24} kg

. Calculate the energy needed to lift one kilogram from the surface of Venus to a space station in orbit

900 km

from the surface.

MEDIUM

AS and A Level

IMPORTANT

Physics for Cambridge International AS & A Level Coursebook 3rd Edition Digital Access>Chapter 17 - Gravitational Fields>EXAM-STYLE QUESTIONS>Q 12

Explain what is meant by the gravitational field strength at a point.This diagram shows the dwarf planet, Pluto, and its moon, Charon.These can be considered to be a double planetary system orbiting each other about their joint centre of mass.

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