Question

A body of mass $2$ $kg$ is placed on a horizontal surface having coefficient of kinetic friction $0.4$ and coefficient of static friction $0.5$. If a horizontal force of $2.5$ $N$ is applied on the body, the minimum force required to slide the body is( take $g=10m/s^2$) :

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

Answer 1

Answer: (B)

10 N

Given:

$m=2kg{\mu }_k=.4{\mu }_s=.5F=2.5$

Normal force acting on the body

$N=mg$

$N=2\times 10$

$N=20N$

Static Frictional Force

$f_{max}=coefficientofstaticFriction\times Normalforce$

$f_{max}=0.5\times 20$

$f_{max}=10N$

If applied force is just greater then the $f_{max}=10$ then body will start to move