Side B1: Gravitational Fields | Year 13

Topic Overview

What students will cover

This topic develops gravitational field models from definitions through orbital applications. Keep the build-up from field strength to potentials and orbits clear as you work through the topic.

You begin by defining gravitational field strength and representing fields with field lines. The next lessons use Newton’s law of gravitation to model forces and field strength around point masses, then develop gravitational potential and potential energy. The topic closes by applying the same ideas to circular and geostationary orbits before you consolidate the topic through revision and review.

Revision

Topic revision route

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Targeted lessons

Revision

Recall vocabulary

Gravitational field
a region where a mass experiences a force; gravitational field strength is force per unit mass.
field strength
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
field lines
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point mass
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
inverse square law
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centripetal acceleration
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
geostationary orbit
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
Gravitational potential
the work done per unit mass in bringing a small test mass from infinity to the point.
gravitational potential energy
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
force per unit mass
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Newton's law of gravitation
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gravitational constant
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potential energy
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
work done
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infinity
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
circular orbit
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
orbital period
A definition has not been added for this term yet. Use the lesson sequence below to review where it appears.
satellite
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Resource bank

Lesson resources: 5
Topic resources: 0

Open the relevant lesson first, then use its linked slides, worksheets, simulations, or practice tasks.

Syllabus

CIE 9702 coverage in this topic

12 points across 7 lessons

Show details

13.1.1

understand that a gravitational field is an example of a field of force and define gravitational field as force per unit mass

L01 Fields and Field Strength L05 Revision L06 Test L07 Review

13.1.2

represent a gravitational field by means of field lines

L01 Fields and Field Strength L05 Revision L06 Test L07 Review

13.2.1

understand that, for a point outside a uniform sphere, the mass of the sphere may be considered to be a point mass at its centre

L02 Newton's Law of Gravitation L05 Revision L06 Test L07 Review

13.2.2

recall and use Newton’s law of gravitation F = Gm1m2 / r2 for the force between two point masses

L02 Newton's Law of Gravitation L05 Revision L06 Test L07 Review

13.2.3

analyse circular orbits in gravitational fields by relating the gravitational force to the centripetal acceleration it causes

L04 Orbits L05 Revision L06 Test L07 Review

13.2.4

understand that a satellite in a geostationary orbit remains at the same point above the Earth’s surface, with an orbital period of 24 hours, orbiting from west to east, directly above the Equator

L04 Orbits L05 Revision L06 Test L07 Review

13.3.1

derive, from Newton’s law of gravitation and the definition of gravitational field, the equation g = GM / r 2 for the gravitational field strength due to a point mass

L02 Newton's Law of Gravitation L05 Revision L06 Test L07 Review

13.3.2

recall and use g = GM / r 2

L02 Newton's Law of Gravitation L05 Revision L06 Test L07 Review

13.3.3

understand why g is approximately constant for small changes in height near the Earth’s surface

L02 Newton's Law of Gravitation L05 Revision L06 Test L07 Review

13.4.1

define gravitational potential at a point as the work done per unit mass in bringing a small test mass from infinity to the point

L03 Potential Energy and Potentials L05 Revision L06 Test L07 Review

13.4.2

use ϕ = –GM / r for the gravitational potential in the field due to a point mass