Hire a tutor

What is the coefficient of restitution?

The coefficient of restitution is a measure of the elasticity of a collision between two objects.

When two objects collide, some of the kinetic energy is lost due to deformation and other factors. The coefficient of restitution (e) is defined as the ratio of the final velocity of separation to the initial velocity of approach:

e = (v2 - v1) / (u1 - u2)

where v1 and v2 are the final velocities of the two objects after the collision, and u1 and u2 are their initial velocities. The coefficient of restitution is always between 0 and 1, where 0 represents a completely inelastic collision (where the objects stick together after the collision) and 1 represents a completely elastic collision (where no kinetic energy is lost).

The coefficient of restitution can be used to predict the outcome of collisions between objects. For example, if the coefficient of restitution is close to 1, the collision is likely to be elastic and the objects will bounce off each other. If the coefficient of restitution is close to 0, the collision is likely to be inelastic and the objects will stick together after the collision.

Understanding the kinetic energy transformations during collisions can be enriched by exploring basic differentiation rules, which help analyse the changes in velocities. Moreover, to comprehend more about the practical applications of the coefficient of restitution, such as in sports equipment and vehicle safety, further reading is recommended.

For those interested in the mathematical underpinnings, particularly how different types of functions behave under differentiation, the page on differentiation of exponential and logarithmic functions can provide additional insights into how to handle more complex scenarios in physics and engineering.


The coefficient of restitution is an important concept in physics and engineering, and is used in many applications such as sports equipment design, car safety testing, and materials science.

Study and Practice for Free

Trusted by 100,000+ Students Worldwide

Achieve Top Grades in your Exams with our Free Resources.

Practice Questions, Study Notes, and Past Exam Papers for all Subjects!

Need help from an expert?

4.92/5 based on480 reviews

The world’s top online tutoring provider trusted by students, parents, and schools globally.

Related Maths a-level Answers

    Read All Answers
    Loading...