Friction occurs when a object rolls over a surface

Rolling friction occurs when a object rolls overs a surface.

Explanation:

Friction is the resisting force which occurs during contact of two objects leading to preventing its motion. The loss due to friction is released in the form of heat energy.

When two objects come in contact with each other for any kind of motion, the electromagnetic attraction of the charges exhibited by the two objects leads to resisting the motion of the object with the release of heat energy.

In this case, when a object is rolling over a surface, the roughness of the surface will contribute to the friction between the surface and the rolling object leading to variation of the speed of the rolling object. This kind of friction experienced by a rolling object is termed as rolling friction.

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