Name the force which increases when the two surface in contact are made more rough.

Why frictional force gets increased when two surfaces in contact are polished beyond a certain limit ?

Which force gets reduced when the two surface in contact are polished to make them smooth ?

Friction depends on the _____ of two surfaces in contact.

Friction depends on the _____ with which the two surfaces in contact are pressed together.

Figure shows two block A and B pushed against the wall with the force F . The wall is smooth but the surfaces in contact of A and B are rough. Which of the following is true for the system of blocks to be at rest againts wall?

Name two contact forces.

In equilibrium, limiting force of static friction (F_(s)) acting between two surface in contact and applied force (F) is related by

Friction between any two surfaces in contact is the force that opposes the relative motion between them The force of limiting friction (F) between any two surfaces in contact is directly proportional to the normal reaction (R) between them F prop R or F = mu R where mu is coefficient of limiting friction If theta is angle of friction then mu = tan theta A force of 49N is just able to move a block of wood weighing 10kg on a rough horizontal surface The coefficient of friction is .

Consider the situation shown in the figure. The wall is smooth but the surfaces of A and B in contact are rough. Then,