Newton's Laws of Motion

Question 1

Newton’s 3 Laws

Answer 1

1) Law of Inertia
2) Law of acceleration
3) Law of action and reaction

Question 2

1) Law of Inertia

Answer 2

An object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.

Question 3

Outside forces affecting inertia:

Answer 3

> playing surface (friction)
gravity/air resistance
the opposition
the breaking action (to stop)
movement of leg to kick a ball

Question 4

Sporting Examples: Law of Inertia

Answer 4

> a rugby player applies force to a stationary ball - it travels over the posts
a tennis player applies force to the ball, to return a shot

Question 5

2) Law of acceleration

Answer 5

The change in velocity of an object is directly proportional to the force applied, and inversly propotional to the mass of the object.

Question 6

Equation: Law of acceleration

Answer 6

Force (N) = Mass (kg) x Acceleration (m/s^2)

F=ma

Question 7

Sporting Examples: Law of acceleration

Answer 7

> throwing a shot put and a tennis ball with the same force - the tennis ball will travel further
tennis serve: toss up - the downward force of gravity gradually slows the pace of the ball, and causes it to fall back down
the harder a ball is thrown (force), the further it will travel

Question 8

3) Law of action and reaction

Answer 8

For every action, there is an equal and opposite reaction.

Question 9

Sporting Examples: Law of action and reaction

Answer 9

> sprint start - athlete pushes off the blocks (action), the blocks push forward on the athlete (reaction), to produce acceleration
weight-lifting - athlete exerts a force against the weight to hold it above their head (action), and gravity exerts and equal and opposite force on the weight (reaction), causing the weight to fall back down