## Learn more physics!

*Most recent answer: 03/12/2017*

Q:

If a rubber ball strikes a rubber surface is the bounce greater than if strikes an elastic surface, such as hardwood? As a corollary is there an optimal speed at contact that would accelerate the bounce?

- Ron Sing (age 57)

Charlotte, NC

A:

Yes it does. When an elastic ball bounces from a surface, some of its energy is lost in the ball as well as the surface. The ratio of the final velocity divided by the the initial velocity is equal to the product of the **coefficient of restitution** of the respective materials. The **cof** can range to near one for a steel plate and close to zero for a plate of gello. The **cof** of wood is about 0.60 and that of rubber is about 0.83. So the ball will bounce higher on a rubber surface..

LeeH

*(published on 03/12/2017)*

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