4. Gravitational Fields

Question 1

Gravitational Field Strength

Answer 1

The force per unit mass on a small test mass placed in the field

Question 2

Field Line

Answer 2

The path a small test mass placed in a field follows

Question 3

Gravitational Potential Energy

Answer 3

The work done to move a small object from infinity to that point (always negative)

Question 4

Gravitational Potential, V

Answer 4

The work done per unit mass to move a small object from infinity to this point (equal to the gravitational potential energy per unit mass of a small test mass)

Question 5

Equipotentials

Answer 5

Lines of constant potential

Question 6

Potential Gradient at a point

Answer 6

The change of gravitational potential per metre at that point in the gravitational field

Question 7

Kepler’s Third Law

Answer 7

r^3/T^2 = constant

Question 8

r^3/T^2 is equal to…

Answer 8

GM/4π^2

Question 9

Field

Answer 9

A region of space where forces act at all points

Question 10

Newton’s Theorem

Answer 10

Uniform spherical masses act as if all their mass is concentrated in a point at its centre

Question 11

Gravitational Potential Difference

Answer 11

∆V - a change in gravitational potential