Momentum Calculator
Free calculate momentum from mass and velocity using p = mv. Get instant, accurate results with our easy-to-use calculator.
Input Parameters
Results
Enter mass and velocity to calculate
What is Momentum?
Momentum is a measure of the quantity of motion an object has. It's the product of an object's mass and velocity, and is a vector quantity (has both magnitude and direction).
Momentum is conserved in isolated systems, meaning the total momentum before a collision equals the total momentum after. This conservation law is fundamental in understanding collisions, explosions, and many physical phenomena.
Momentum is directly related to force through Newton's second law: F = Δp/Δt. The rate of change of momentum equals the net force acting on an object.
Momentum Formula
Where:
- • p = Momentum (kg·m/s)
- • m = Mass (kg)
- • v = Velocity (m/s)
Note: Momentum is a vector - direction matters! For collisions, use vector addition.
How to Calculate Momentum
-
1
Convert mass to kilograms
Convert all mass units to kg for consistent calculations.
-
2
Convert velocity to m/s
Convert km/h or mph to meters per second (1 km/h = 0.2778 m/s, 1 mph = 0.447 m/s).
-
3
Apply the formula
Calculate p = m × v
Practical Examples
Example 1: Moving Car
A 1500 kg car travels at 20 m/s. Calculate its momentum.
Solution:
p = m × v = 1500 kg × 20 m/s
p = 30,000 kg·m/s
Example 2: Baseball
A 0.145 kg baseball is thrown at 40 m/s. What is its momentum?
Solution:
p = 0.145 kg × 40 m/s
p = 5.8 kg·m/s
Applications
Collision Analysis
Understanding car crashes, sports collisions, and any impact scenarios using conservation of momentum.
Rocketry
Calculating thrust, understanding rocket propulsion, and analyzing momentum transfer in space missions.
Sports
Analyzing ball speeds, impact forces, and understanding energy and momentum transfer in sports.
Engineering
Designing safety systems, understanding impact forces, and analyzing mechanical systems.
Frequently Asked Questions
What is the difference between momentum and kinetic energy?
Momentum (p = mv) is a vector and depends linearly on velocity. Kinetic energy (KE = ½mv²) is a scalar and depends on velocity squared. Both are conserved in different ways.
Is momentum always conserved?
Yes, in isolated systems (no external forces), total momentum is always conserved. This is one of the most fundamental laws in physics.
Can momentum be negative?
Yes! Momentum is a vector. Negative momentum means motion in the opposite direction. In one dimension, +p means one direction, -p means the opposite.
How does momentum relate to force?
Force equals the rate of change of momentum: F = Δp/Δt. This is Newton's second law in its most general form, more fundamental than F = ma.
What happens to momentum in elastic vs inelastic collisions?
Momentum is conserved in both types. In elastic collisions, kinetic energy is also conserved. In inelastic collisions, some kinetic energy is lost, but momentum remains constant.