What makes a collision 'elastic'?

An elastic collision conserves both total momentum and total kinetic energy — real-world collisions are rarely perfectly elastic, but billiard balls and gas molecule collisions come close.

Elastic Collision Velocity Calculator

Calculate the resulting velocities of two objects after a perfectly elastic collision, where both momentum and kinetic energy are conserved.

Inputs

Results

Final Velocity 1: -3.4 m/s
Final Velocity 2: 3.6 m/s

Try an example

Formula

v1' = ((m1−m2)/(m1+m2))v1 + (2m2/(m1+m2))v2, and symmetric for v2'

Learn How This Works

Motion and Collisions: Impulse, Angular Velocity, and Friction

Impulse, angular velocity, elastic collisions, and the coefficient of friction — four foundational mechanics calculations.

Frequently Asked Questions

Related Calculators

Momentum Calculator

Calculate the momentum of a moving object.

Kinetic Energy Calculator

Calculate the kinetic energy of a moving object.

Force Calculator (F=ma)

Calculate force from mass and acceleration using Newton's second law.

Gravitational Potential Energy Calculator

Calculate gravitational potential energy from mass and height.

Acceleration Calculator

Calculate acceleration from change in velocity over time.

Projectile Range Calculator

Calculate the horizontal range of a projectile launched at an angle.