Which of the following statements is correct about friction?

Options

A. The coefficient of friction between a given pair of substances is largely independent of the area of contact between them.
B. The frictional force can never exceed the reaction force on the body from the support surface.
C. Rolling friction is only slightly smaller than slidmg friction.
D. The main source of friction is the irregularity of the surfaces in contact.

Answer

A

Explanation

The coefficient of friction between a given parir of substance is independent of the area of contact between them.`"mu" gt1` for copper on cast iron. Rolling friction is much smaller than sliding friction. Irregularity of the surfaces in contact is not a main contributor of riciton.