Gravitational fields

Question 1

Gravitational Potential Energy

Answer 1

The amount of energy required to move a mass from infinity to a given point in a gravitational field.

Question 2

Escape Velocity

Answer 2

The velocity a mass needs in order to move away from a source mass to a distance where the gravitational field is negligible.

Question 3

Gravitational Field

Answer 3

A region in which a mass experiences a non-contact force.

Question 4

Gravitational Field Strength, g

Answer 4

Gravitational force per unit mass that a mass would experience in a gravitational field.

Question 5

Gravitational Potential

Answer 5

Gravitational potential energy per unit mass.

V = Ep/m = -GM/r

Question 6

Gravitational Potential Difference

Answer 6

Energy required per unit mass to move a mass from one point in a gravitational field to another.
The work done to move a unit mass from one point in a gravitational field to another.

ΔV = ΔEp/m

Work Done to move a mass between two points = gravitational potential difference between the points × mass

Question 7

Potential Gradient

Answer 7

The change in potential per meter at a point.

g = -ΔV/Δr

ΔV = area under a field strength graph between two points

Question 8

Keplers third law

Answer 8

T^2 is proportional to r^3