Science
What is Force?
A force is a push or a pull that can change an object's motion, direction, or shape. Forces are why things speed up, slow down, fall, or stay still — from gravity holding you to the ground to friction stopping a rolling ball.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains force.
Key things to understand
- 1A force has both size and direction, and is measured in newtons (N).
- 2Forces cause acceleration: Newton's second law says force = mass × acceleration (F = ma).
- 3Forces come in pairs — for every action there's an equal and opposite reaction (Newton's third law).
- 4Common forces include gravity, friction, tension, and the normal (support) force.
- 5When the forces on an object are balanced, its motion doesn't change; when unbalanced, it speeds up, slows down, or turns.
Frequently asked questions
- What are the four fundamental forces?
- Gravity, electromagnetism, the strong nuclear force, and the weak nuclear force — these underlie every interaction in the universe.
- What's the difference between mass and force?
- Mass is how much matter an object contains; force is the push or pull acting on it. Weight is actually the force of gravity on a mass.
- Can a force exist without movement?
- Yes. If you push a wall it doesn't move, but you still apply a force — the wall pushes back equally, so the forces are balanced.