21.1 - Gravitational field strength

What happens when a test mass is put in a gravitational field of a massive object?

Both objects experience and equal and opposite force due to gravity, however the larger object is too massive to experience any noticeable change. If the small test mass is free to move then it will be attracted towards the larger object.

If the object is not acted upon by any external force, the acceleration of the object will be...

...force/mass = mg/m = g (therefore the acceleration is equal and due to gravity)

If an object of mass, m is in a gravitational field, the gravitational force acting on the object is given by...

...mg.

What is a radial field?

A field where by the field lines all converge on one point. The magnitude of 'g' in a radial field decreases with distance

What is a linear field?

A field whereby the gravitational field strength is uniform. I.e. the same magnitude and direction throughout the field.

What is a gravitational field?

A region where a massive object experiences a force.

How can the strength of a gravitational field be increased?

Increase the mass of a massive object or decrease the distance from the massive object.

Is earth's gravitational field radial or linear, why?

Radial, since 'g' decreases the further from earth you go.

What is the weight of an object?

The force of gravity acting on the object.

Define gravitational field strength.

The force per unit mass, acting on a small test mass placed in a field.

What is the equation to show gravitational field strength?

g=F/m