• Newton’s first law of motion: An object’s speed will only change if a force is applied.

• Newton’s second law of motion: Speed or acceleration is proportional to the force.

• Newton’s third law of motion: Every action has an equal and opposite reaction.

• Forces can’t be seen, but the effect of a force can be seen.

• They are measured in newtons – N

• They usually act in pairs (1st Law of motion)

• They always act in certain direction

• A newton meter is used to measure forces.

Two things make up a force

1. its size, how strong a push or pull is, and

2. its direction, which way it pushes or pulls.

We draw forces as arrows.

1. The length of the arrow shows how strong the force is and 2. way it points shows the direction of the force.

Balanced Forces produce

NO change in Movement

Unbalanced Forces

Change the Speed and or

Direction of Moving Objects

Balanced and Unbalanced Forces

The forces on the person are balanced

The floor pushes upward on the person

Gravity pulls downwards on the

person

Greater Force

Smaller Force

Forces & MovementForces are nearly always

PUSHES and PULLS

Forces can make objects do FIVE things

1. Speed up

Like kicking a ball

2. Slow down

Like drag or air resistance

3. Change Direction

Like hitting a ball with a bat

4. Turn

Like turning a spanner

5. Change shape

Like stretching, twisting, compressing and Bending

Look at some of the forces in action

• Are they Balanced or Unbalanced?

Tasks

Now draw the arrows to show the

• Direction of the forces

• Strength of the forces

Show the forces acting on the Owl sitting and reading

Is the force acting on the Owl balanced or unbalanced?

Think about this situationsIf you were pushing these elephants to move…1. Which will need more force to move? Why? 2. Which direction would they be travelling? Why?3. Which elephant will move faster? Why?

Where are the forces acting on this clock

Where are the forces acting?

Where are the forces acting?

Where are the forces acting?

Where are the forces acting?

Where are the forces acting?

Where are the forces acting? Look carefully at the insect and the frog

Where are the forces acting?Look carefully at the motion of the ball