Calculate linear momentum with p = m v — enter mass and velocity, or solve for either. Momentum is measured in kilogram-metres per second (kg·m/s).
Linear momentum is the product of an object's mass and velocity: p = m v. It is a vector, pointing in the direction of motion, with units of kg·m/s.
Momentum matters because it is conserved: in the absence of external forces, the total momentum of a system stays constant. This is the principle behind collisions, recoil and rocket propulsion. A change in momentum equals the impulse, F·Δt.
Momentum is p = m v — mass times velocity. Mass is in kilograms and velocity in metres per second, giving kg·m/s.
Momentum (mv) is a vector and is conserved in all collisions. Kinetic energy (½mv²) is a scalar and is only conserved in perfectly elastic collisions. Energy grows with velocity squared; momentum grows linearly.
The total momentum of an isolated system (no net external force) is always conserved, even when kinetic energy is lost to heat or deformation in an inelastic collision.
Kilogram-metres per second (kg·m/s), which is equivalent to newton-seconds (N·s).