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Formula Vault Physics Mechanics
Physics · Mechanics

Momentum

The “quantity of motion” of a moving object.

p = mv

1What it means

Momentum measures how hard it is to stop a moving object. A heavy, fast object has large momentum. It is measured in kg·m/s.

2Variables

SymbolMeaning
pMomentum (kg·m/s)
mMass (kg)
vVelocity (m/s)

3Worked examples

Example 1 Worked solution
Q. Find the momentum of a 2 kg ball moving at 5 m/s.
  1. p = m × v = 2 × 5.
✓ p = 10 kg·m/s

4Where it's used

  • Collision and recoil problems.
  • Understanding why heavy vehicles are harder to stop.

5Tips & common mistakes

  • !Momentum has direction — it is a vector.
  • !Total momentum is conserved in collisions.