5.2 Gravitational Fields

Question 1

Define gravitational field strength

Answer 1

The grav. field strength at a point is equal to the force which would be produced on a test mass of 1kg at that point

Question 2

What is Newton’s Law of Universal Gravitation?

Answer 2

Between every two point masses there exists an attractive gravitational force which is directly proportional to the product of the masses and inversely proportional to the square of their separation

Question 3

What three conditions make a satellite a geostationary satellite?

Answer 3

• orbits the earth directly above the equator
• orbits in the same direction as the earth rotates
• has an orbital period of exactly 24 hours

Question 4

What kind of satellite appears to an observer on earth to be stationary?

Answer 4

a geostationary satellite

Question 5

what is a geosynchronous satellite?

Answer 5

a satellite with a period equal to the Earth’s rotational period

Question 6

name one way for satellite to generate their own energy

Answer 6

from solar radiation

Question 7

what would satellites use self-generated energy for?

Answer 7

to power electronics and other instruments on board

Question 8

what is Kepler’s Third Law?

Answer 8

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

Question 9

A satellite orbiting earth at a height of —–km or less can be said to have an orbital radius equal to earth’s radius

Answer 9

200km