# Why is the work done by friction zero when body is rolling? [duplicate]

Why is the work done by friction zero when body is rolling? Does it mean no energy is dissipated by friction.

• Also, related answer Mar 12, 2019 at 19:07

In order for a rolling wheel not slip friction is required between at the contact point between the wheel and the surface. The necessary traction is determined by the coefficient of static friction between the tire and the surface.

But if the wheel is not slipping, the static friction force does not perform any work against the wheel’s motion. It is only when there is slipping that sliding friction does work. This is false The above is under ideal conditions. There is always friction at the axle. And the flexing of the tire treads is a form of friction.

Hope this helps.

• It means no energy is dissipated and also how is the work done zero. Mar 12, 2019 at 16:16
• Ground won't be hot Mar 12, 2019 at 16:16

Why is the work done by friction zero when body is rolling?

When rolling on horizontal ground, there is no friction. Nothing is affecting the surfaces in contact (wheel and ground), so there is no tendency to slide and thus no need for a static friction.

When rolling on an incline, there is static friction - because there is gravity causing a torque. This torque would make the surface slide, so static friction appears to prevent sliding. Friction still doesn't do any work - gravity does that work.

Does it mean no energy is dissipated by friction.

In usual situations, yes, static friction causes no energy dissipation - no energy loss or gain.