Example: person “at rest”​

These forces are balanced (weight and normal force are equal)

The person is “at rest”.

If the chair could not balance the force of gravity she would fall through.​

Balanced forces​

For forces to be balanced then:

• The magnitude (size) of the two forces must be equal.

• The direction of the two equal forces must be opposite.

The objects motion will not change.​

Unbalanced forces​

When one force is bigger than another the forces are unbalanced.

This will cause:

• A change in motion 

  (start, stop, speed up or slow down)

• A change in direction

• A change in shape​

Start/Stop moving

Acceleration/deceleration

Change in shape/direction

​UNBALANCED

Constant speed

OR

At rest

​

BALANCED

​Net Force

​Net force is the total force acting on an object.

• Add the forces when they operate in the SAME direction.

Subtract the forces when they operate in DIFFERENT directions.