Newton's Third Law
- Newton's Third Law states:
If body A exerts a force on body B, then body B will exert a force on body A of equal magnitude but in the opposite direction
- This means that every force has a paired equal and opposite force
- Newton’s Third Law force pairs must act on two different objects
- Newton’s Third Law force pairs must also be of the same type e.g. gravitational or frictional
Worked example
Using Newton's third law describe why when a balloon is untied, it travels in the opposite direction.
Exam Tip
You may have heard Newton’s Third Law as: ‘For every action is an equal and opposite reaction’. However, try and avoid using this definition since it is unclear on what the forces are acting on and can be misleading.
Newton’s Third Law force pairs are only those that act on different objects
