Question

Define interlocking in friction

Answer 1

Friction is a result of  interlocking.

Every object has some irregularities or roughness on its surface. when two different  surfaces come in contact , their irregularities go into each other and they interlock.

Therefore, the  frictional force  will be greater in case of rough surface than smooth surface.

To move one body against the other , this interlocking force has to be overcome by application of force.

Answer 2

To move an object against the other this interlocking has to be overcome by application of force