Newton's Laws of Motion
- First law: An object stays at rest or moves at constant velocity unless acted on by a resultant force.
- Second law: Force = mass × acceleration (
F = ma). - Third law: For every action, there is an equal and opposite reaction.
Worked example
A 10 kg object accelerates at 2 m/s². The force required is F = 10 × 2 = 20 N.