Newtons Laws of Motion

Question 1

State Newton’s first law of motion

Answer 1

Law of inertia: A body continues in a state of rest or uniform velocity unless acted upon by an external or unbalanced force

Question 2

Define Newton’s second law of motion

Answer 2

Law of acceleration: A body’s rate of change in momentum is proportional to the size of the force applied and acts in the same direction as the force applied

Question 3

Define Newton’s third law of motion

Answer 3

Law of reaction: for every action force applied to a body there is an equal and opposite reaction force

Question 4

Example of Newtons first law in sport

Answer 4

A 100m sprinter will remain at rest in the blocks until an external force large enough to overcome their inertia creates motion.

Question 5

Example of Newtons second law of motion

Answer 5

The greater the force applied to the sprinter the greater the rate of change in acceleration away from the blocks. The force is applied in a forward direction and so the sprinter drives towards the line

Question 6

Example of Newtons third law

Answer 6

When the 100m sprinter applies a down and backward action force into the blocks, the blocks provide an equal and opposite up and forward reaction force to the sprinter to drive them out of the blocks