5.2 Gravitational Fields

Question 1

State

Newtons Law of Universal Gravitation

Answer 1

There is a force of attraction between every 2 point masses which is directly proportional to the product of their masses and inversely proportional to the square of their separation.

Question 2

Equation

Newtons Law of Universal Gravitation

Answer 2

F = G x ^{M₁ x M₂⁄_r2}

Question 3

Define

Gravitational field strength

Answer 3

This is defined as the force acting on unit mass (1kg) at a point in the field.

Question 4

Equation

Gravitational field strength

Answer 4

g = ^GM⁄_r²

Question 5

State

Kepler’s 3rd law

Answer 5

The square of the period of revolution of the planets about the sun is directly proportional to the cube of their mean distances from it.