Momentum Calculator
Enter any two of mass, velocity and momentum to solve p = m x v. Add a force and a time to also find the impulse, which equals the change in momentum.
How to calculate momentum
- Enter two of mass, velocity and momentum to solve for the third.
- Velocity can be negative to show direction; mass must be positive.
- Add a force and a time if you also want the impulse in newton seconds.
Examples
Momentum from mass and velocity
m = 2 kg, v = 3 m/s
p = 6 kg m/s
Impulse from force and time
F = 10 N, t = 0.5 s
impulse = 5 N s
Frequently asked questions
What is linear momentum?
Linear momentum is mass times velocity, p = m x v. It is measured in kilogram metres per second and points in the same direction as the velocity.
What is impulse?
Impulse is the force applied times the time it acts, J = F x t. By the impulse momentum theorem it equals the change in an object's momentum.
Can momentum be negative?
Yes. Momentum takes the sign of the velocity, so motion in the negative direction gives negative momentum. Mass itself is always positive.
How do I find velocity from momentum?
Rearrange to v = p / m. Divide the momentum by the mass to get the velocity, including its sign for direction.
What units does this use?
Mass in kilograms, velocity in metres per second, momentum in kg m/s, force in newtons and time in seconds, so impulse comes out in newton seconds.
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