Question

Consider the situation shown in figure. The wall smooth but the surface of A and B in contact are rough. The friction on B due to A in equilibrium
Figure

(a) is upward
(b) is downward
(c) is zero
(d) the system cannot remain in equilibrium.

Answer 1

(d) the system cannot remain in equilibrium.


Since the wall is smooth and the surface of A and B in contact are rough, the net vertical force on the system is in the downward direction. Hence, the system cannot remain in equilibrium.