3.7.2 - DEFINITIONS

Question 1

escape velocity

Answer 1

the minimum velocity required by an object to be able to escape a gravitational field of a mass when projected vertically from its surface

Question 2

equipotential

Answer 2

a surface of constant potential. no work is done by the field when an object moves along an equipotential

Question 3

geostationary satellite

Answer 3

a satellite that orbits above the equator with a 24 hour period, so it will always remain above the same position on the Earth.

Question 4

gravitational field

Answer 4

a region surrounding a mass in which any other object with mass will experience an attractive force

Question 5

gravitational field strength

Answer 5

the force per unit mass exerted on a small test mass placed within the field

Question 6

gravitational potential

Answer 6

the work done per unit mass required to move a small test mass from infinity to that point

Question 7

gravitational potential energy

Answer 7

the component of an object’s energy due to its position in a gravitational field

Question 8

Kepler’s third law

Answer 8

the square of an object’s orbital period (T) is directly proportional to the cube of its orbital radius

Question 9

uniform field

Answer 9

a field in which all of the field lines are parallel and equally spaced - field strength is equal in all its areas