Question

A block of mass 2 kg is kept on the floor. The coefficient of static friction is 0.4. If a force of 2.5 N is applied on the block as shown in the figure, the frictional force between the block and the floor will be

• A. 2.5 N
• B. 5 N
• C. 7.84 N
• D. 10 N

Answer 1

Answer: (A)

Given:
$\mu =0.4F=2.5N$
$m=2kg$
$N=mg=20N$
The max value of friction $=\mu N=0.4\times 20=8N$
Since, the force applied is $2.5N$ there is no need for friction to attain its max.
value.
$\therefore$ Frictional force $=2.5N$