Linear momentum
Newton's Laws & Momentum - OCR A-Level Physics
Key Definition
Linear momentum
The product of an object's mass and its velocity. A vector quantity with the same direction as the velocity. SI unit: kg $m s^{-1}$ (equivalent to N s).
The product of an object's mass and its velocity. A vector quantity with the same direction as the velocity. SI unit: kg $m s^{-1}$ (equivalent to N s).
$$p = mv$$
- Momentum is a vectorA quantity with both magnitude and direction (e.g. force, velocity, displacement).: direction matters. Always choose and state a positive direction
- Objects moving in opposite directions have momenta with opposite signs
- A heavy, slow object can have the same momentum as a light, fast object
- The total momentum of a system is the vector sum of individual momenta