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 $(g=10m/s^2)$

• A. $8N$
• B. $6N$
• C. $2.5N$
• D. $10N$

Answer 1

The correct option is D. $10N$

Given, $Mass=2kg$

Kinetic friction is $0.4$

Static friction is $0.5$

$F=2.5N$

So, the minimum force required is equal to the limiting friction

$f_{max}=\mu N=\mu mg=0.5\times 2\times 10=10N$.

or,

$f_{max}$ = 10 N > 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 horizontally applied force will be equal.

Therefore, f = 2.5 N.