D.1 Gravitational Fields

Question 1

Newtons universal law of gravitation

Answer 1

“Every single point mass attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of their separation.”

Question 2

Point mass

Answer 2

A mass which doesn’t take up any space (infinitely small).

Question 3

Gravitational Field

Answer 3

A region of space where a mass experiences a force because of its mass

Question 4

Gravitational field strength

Answer 4

The force per unit mass experienced by a small point mass placed at that point

Question 5

Field strength on a point mass in between two larger objects

Answer 5

The field strength at that point is the sum of the individual field strengths

Question 6

Orbital motion

Answer 6

The motion of one body around another, it has a curved path

Question 7

Keplers first law

Answer 7

Planets move on ellipses with the sun at one of the foci of the ellipse

Question 8

Perihelion

Answer 8

The point at which a planet in elliptical orbit will be closest to the sun

Question 9

Aphelion

Answer 9

The point at which a planet in elliptical orbit will be furthest away from the sun

Question 10

Keplers second law

Answer 10

The line joining a planet and the sun sweeps equal areas in equal times

Question 11

Formula showing planets move faster at the perihelion

Answer 11

Vp/Va=SA/SP

Question 12

Keplers Third law

Answer 12

The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.