Inertia and Newton's Third Law

Question 1

What is Newton’s Third Law?

Answer 1

When two objects interact, the forces they exert on each other are equal and opposite

Question 2

True or false? When you push a swing, the swing pushes back with the same force

Answer 2

True

Question 3

Isaac uses a golf club to hit a melon forwards with a force of 200N. What’s the magnitude and direction of the force the melon exerts on the club?

Answer 3

200N backwards/opposite to the direction of the motion of the melon

Question 4

A melon smashing world championship trophy sits on a shelf. State a pair of forces that illustrates Newton’s Third Law in this situation.

Answer 4

The upwards normal contact force of the shelf on the trophy and the downwards normal contact force of the trophy on the shelf. / The gravitational force of the Earth acting on the trophy and the gravitational force of the trophy acting on the Earth.

Question 5

What is more difficult to get moving, a 5 kg block or a 7 kg block? Explain your answer

Answer 5

The 7 kg block. It has a greater inertial mass, so it will be harder to change its velocity

Question 6

What is inertial mass a measure of? What’s the formula you can use to find it?

Answer 6

A measure of how difficult it is to change the velocity of an object
m = F / a