Momentum Calculator

Calculate linear momentum using p = mv. Enter mass and velocity to find momentum in kg⋅m/s (N⋅s). Includes examples for common objects.

kg
m/s

MOMENTUM

50 kg⋅m/s


IN N⋅s

50 N⋅s

KE

125 J

FORMULA

p = m × v

Momentum — Common Examples

ObjectMassSpeedMomentum
Baseball (pitched)0.145 kg40 m/s5.8 kg⋅m/s
Football (kicked)0.41 kg28 m/s11.48 kg⋅m/s
Person (running)75 kg5 m/s375 kg⋅m/s
Car (city)1500 kg13.4 m/s20,100 kg⋅m/s
Bowling ball6.35 kg8 m/s50.8 kg⋅m/s

💡 How to Calculate Momentum

What Is Momentum?

Momentum is a measure of how much motion an object has. It depends on both an object's mass and its velocity. A heavy object moving slowly can have the same momentum as a light object moving quickly.

Momentum is a vector quantity — it has both magnitude and direction. It is one of the most important concepts in physics because of the law of conservation of momentum, which governs every collision and interaction.

How to Calculate Momentum

Momentum Formula

p = m × v

Where:

  • p = momentum (kg⋅m/s or N⋅s)
  • m = mass (kg)
  • v = velocity (m/s)

For example, a 1,500 kg car traveling at 30 mph (13.4 m/s) has a momentum of:

p = 1,500 × 13.4 = 20,100 kg⋅m/s

Conservation of Momentum

In any closed system where no external forces act, the total momentum before an event equals the total momentum after. This applies to billiard ball collisions, car crashes, rocket propulsion, and nuclear reactions.

Impulse-Momentum Theorem

The impulse-momentum theorem states that the change in momentum equals force multiplied by time:

F × Δt = Δp = m × Δv

This explains why airbags work — by increasing the collision time, they reduce the force on passengers while absorbing the same change in momentum.

A 1,500 kg car at 30 mph has 20,100 kg⋅m/s of momentum. Airbags reduce force by increasing collision time (impulse).

Momentum Calculator FAQ