Enter the relative velocity after collision (m/s) and the relative velocity before collision (m/s) into the Calculator. The calculator will evaluate the Coefficient of Restitution.

## Coefficient of Restitution Formula

e = V2rel / V1rel

Variables:

• e is the Coefficient of Restitution ()
• V2rel is the relative velocity after collision (m/s)
• V1rel is the relative velocity before collision (m/s)

To calculate the Coefficient of Restitution, divide the velocity after the collision by the velocity before the collision.

## How to Calculate the Coefficient of Restitution?

The following steps outline how to calculate the Coefficient of Restitution.

1. First, determine the relative velocity after collision (m/s).
2. Next, determine the relative velocity before collision (m/s).
3. Next, gather the formula from above = e = V2rel / V1rel.
4. Finally, calculate the Coefficient of Restitution.
5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem :

Use the following variables as an example problem to test your knowledge.

relative velocity after collision (m/s) = 35

relative velocity before collision (m/s) = 60

### What is the Coefficient of Restitution?

The Coefficient of Restitution (e) is a measure of the elasticity of a collision between two bodies. It is calculated by dividing the relative velocity of the bodies after the collision by their relative velocity before the collision.

### How does the Coefficient of Restitution affect a collision?

The Coefficient of Restitution affects how much kinetic energy is conserved in a collision. A value of 1 indicates a perfectly elastic collision, where no kinetic energy is lost, while a value of 0 indicates a perfectly inelastic collision, where all kinetic energy is converted to other forms of energy.

### Can the Coefficient of Restitution be greater than 1 or negative?

No, the Coefficient of Restitution typically ranges from 0 to 1. A value greater than 1 or negative would imply that the collision results in a gain of kinetic energy from an external source, which violates the principle of conservation of energy.

### How can the Coefficient of Restitution be used in real-world applications?

The Coefficient of Restitution is used in various fields such as sports science to design better sports equipment, automotive industry for improving vehicle safety by studying collisions, and in mechanical engineering for analyzing and designing collision-involved machinery.