H207 Gravitational Force

Question 1

Define gravitational field.

Answer 1

Gravitational field is a region where a mass experiences a gravitational force.

Question 2

Define a line of force.

Answer 2

A line of force in a gravitational field is the direction of the gravitational force acting on a small test mass.

Question 3

What does Newton’s Law of Gravitation state?

Answer 3

Newton’s Law of Gravitation states that the gravitational force of attraction between two point masses is directly proportional to the product of the masses and inversely proportional to the square of separation between the masses.

Question 4

What are the requirements for a satellite to be geostationary?

Answer 4

1. Have a period of 24h
2. ORbit directly above the equator
3. Move from west to east
4. Must be in a circular orbit a particular radius.

Question 5

Define gravitational field strength.

Answer 5

Gravitational field strength at a point in the gravitational field is the gravitational force of attraction per unit mass acting on a small test mass placed at that point in the field.

Question 6

What is the formula for gravitational field strength?

Answer 6

g = GM/r^2

Question 7

Define gravitational poential.

Answer 7

Gravitational potential at a point in the gravitational field is the work done per unit mass in bringing a small test mass from infinity to that point in the field.

Question 8

What is the formula for gravitational potential?

Answer 8

Gravitational potential = -GM/r

Question 9

What if the formula for gravitational potential energy?

Answer 9

E = m(gravitational potential)

Question 10

What is the formula of the escape velocity?

Answer 10

V = square root (2GM/R)