Gravitational Fields

Question 1

Keplers 1st Law

Answer 1

Orbit of a planet is an ellipse, with sun at one focus

Question 2

Keplers 2nd law

Answer 2

A line segment joint a plant and the sun sweeps out equal areas during intervals of equal time.

(because it moves faster when closer to the sun)

Question 3

Keplers 3rd law

Answer 3

The square of the orbital period is proportional to the cube of the average distance r from the sun

Question 4

GF & EF

Answer 4

Similarity
Field strength ∝ 1/sep^2

Difference
GF linked to m, EF linked to Q
GF always attractive, EF attractive or repulsive