Q. A block of mass $2\ kg$ is kept on the floor. The coefficient of static friction is 0.4. If a force $F$ of 2.5 $Newtons$ 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) $10\ N$
Explanation
(a) Applied force $= 2.5\ N$
Limiting friction $= \mu mg = 0.4 \times 2 \times 9.8 = 7.84\ N$
For the given condition applied force is very smaller than limiting friction
$\therefore$ Static friction on a body = Applied force $= 2.5N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.