21.2 Gravtiational Potential

Question 1

Define gravitational potential

Answer 1

At a point in a gravitational field it is the work done per unit mass to move a small object from infinity to that point

Question 2

What is gravitational potential energy?

Answer 2

It is the energy of an object due to its position in a gravitational field

Question 3

Where is the gravitational potential energy (gpe) equal to zero?

Answer 3

At infinity, up to that point, the gpe would be negative

Question 4

What is an equipotential?

Answer 4

A surface of constant potential

(think of contour lines on a map)`

Question 5

How much work is done moving along an equipotential surface?

Answer 5

None, 0, nuffin, zero,

Question 6

Define potential gradient

Answer 6

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

-Gravitational field strenght is the negative of the potential gradient

Again these can be linked to contour lines, as the closer together contour lines are, the steeper the hills are. Here, the closer the equipotentials are, the higher the potential gradient.

Question 7

The field is uniform so the potential gradient is …

Answer 7

constant, therefore the equipotentials are equally spaced and so the gravitational field strength is constant.