Question

The block shown moves with constant velocity on a horizontal surface. Two of the forces on it are shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is

• A. 0
• B. 2 N, leftward
• C. 2 N, rightward
• D. slightly more than 2 N, leftward

Answer 1

The correct option is B 2 N, leftward

The block moves with constant velocity on horizontal surface, this indicates the acceleration of block is zero,. From newton's IInd law of motion net external force should be zero in case of zero acceleration.
Fnet= 0
Taking right direction as positive force direction
5 N + f N+ (-3) N=0 => f= -2 N where f is frictional force.
the frictional force value is 2N in leftward direction, hence correct answer is B.