Question

A body of mass 2 kg is placed on a horizontal surface having kinetic friction 0.4 and static friction 0.5. If the horizontal force applied on the body is 2.5 N, the frictional force acting on the body will be ( g = 10 $m{s}^2$)

• A. 8 N
• B. 10 N
• C. 20 N
• D. 2.5 N

Answer 1

The correct option is D 2.5 N

The maximum static friction, $f_{s,max}={\mu }_{s}N=0.5\times 2kg\times 10m{s}^{-2}$
or, $f_{s,max}=10N>2.5N$, which is greater than the applied horizontal force.
Hence, friction can impede the motion and the necessary required frictional force to balance the horizontal applied force will be equal.
Therefore, $f=2.5N$.