Gravitational Fields

Question 1

Gravitational field

Answer 1

A force field generated by any object w/mass which causes any other object w/ mass to experience an attractive force

Question 2

Where are the field lines in point masses concentrated ?

Answer 2

Centre of mass

Question 3

Newton’s law of gravitation

Answer 3

A force acting between 2 point masses is ∝ product of masses + inversely ∝ square of distance between

Question 4

Gravitational potential

Answer 4

The work done in moving a unit mass from infinity to that point

Question 5

Escape velocity

Answer 5

v needed so the object has enough kinetic energy to escape a gravitational field

Question 6

Geostationary satellites

Answer 6

• orbit directly over the equator

* sane angular speed as the Earth turns + same direction ∴ stays at same point above earth + one day to orbit

Question 7

Kepler’s 1st law

Answer 7

Each planet moves in an ellipse around the sun w/ sun at one focus

Question 8

Kepler’s second law

Answer 8

A line joining the sun to a planet will sweep out equal areas in equal times

Question 9

Kepler’s third law

Answer 9

T² ∝ r³

Question 10

What affects atmospheric thickness + how

Answer 10

Larger mass = bigger g field ∴ fewer particles escapes into space