Gravitational Fields

Question 1

What is Newtons Third Law?

Answer 1

If Object A exerts a force on Object B, Object B exerts an equal and opposite force on Object A.

Question 2

What does a field line/line of force show?

Answer 2

The path which the smaller mass would move in due to a force.

Question 3

What is the gravitational field strength?

Answer 3

Force per unit mass on a small test mass paced at that point

Question 4

What do equipotential lines show?

Answer 4

Points of equal field strength

Question 5

What do radial field lines look like and why?

Answer 5

Like the spokes of a wheel coming out of the centre of an object. The magnitude of the force decreases as the distance from the object increases.

Question 6

What do uniform field lines look like and why?

Answer 6

Parallel and equally spaced. They have the same magnitude and direction at all points in the field.

Question 7

What is gravitational potentials definition? (V)

Answer 7

The gravitational potential v at a point is the work done per unit mass to move a small object from infinity to that point.

Question 8

Definition for Potential Gradient

Answer 8

Change of potential per meter at that point

Question 9

The three rules for Newtons law of gravitation

Answer 9

1. Force is always attractive
2. Force is proportional to mass of each object
3. Force is proportional to 1/r^2./ Follows inverse square relationship