1
Q
What is a gravitational field?
A
- A region where a mass experiences a force
2
Q
Define gravitational field strength?
A
- g = F / m
3
Q
What is newtons law of gravitation?
A
- F = Gm1m2 / r2
4
Q
Derive the equation g = Gm / r2 for a point mass
A
- F = Gm1m2 / r2 and g = F/m
- mg = Gm1m2 / r2
- g = Gm / r2
5
Q
What is the equation for gravitational potential?
A
- Vgrav = -GM / r
6
Q
State the similarities between G fields and E fields
A
- Both obey the inverse square law F ∝ 1 / r2
- Both act over an infinite range
- Both fields are radial for point objects
7
Q
State the differences between G fields and E fields
A
- G fields are always attractive whilst E fields can be attractive or repulsive
- E fields are stronger than G fields
- E fields only act on charged particles whilst G fields act on all particles with mass
- E fields can be shielded (with a Faraday cage) whilst G fields cannot
8
Q
What might you need to combined with Newtons universal law of gravitation?
A
- Centripetal force equations such as F = mrω2 or F = mv2 / r
9
Q
Where is r measured from?
A
- THE CENTRE
