7) Fields & Their Consequences

Question 1

Why do magnetic forces arise

Answer 1

Fundamentally because of the interaction between charges that have a relative motion between them

Question 2

Why do gravitational forces arise

Answer 2

Because of the interaction between two masses

Question 3

Similarities of gravitational and electrostatic forces

Answer 3

Both have inverse square laws
The equipotential lines around point objects are concentric circles and get further apart for equal changes in potential between lines

Question 4

Differences of gravitational and electrostatic forces

Answer 4

Forces between masses is always attractive
Force between charges can be either attractive or repulsive

Question 5

What is Newton’s law of gravity

Answer 5

Gravity is an attractive force acting between all matter and acts everywhere in the universe

Question 6

Gravitational force formula

Answer 6

Gravitational force = (gravitational constant x first mass x second mass) (distance between the masses)^2
F = (G x m1 x m2) / r^2