Q. An iron block of mass $5\ kg$ is kept on a trolley. If the trolley is being pushed with an acceleration of $5\ m/s^{2}$, What will be the force of friction between the block and the trolley surface? (Take the coefficient of static friction between the block and the surface to be 0.8)
A) Zero
B) $5\ N$
C) $4\ N$
D) $25\ N$
Explanation
(d) $m = 5kg,\ a = 5\ m/s^{2}$
$\because F \leq fr_{\max} \leq \mu N$
$F = ma = 5 \times 5 = 25N$
$\therefore fr = F \Rightarrow fr = 25N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.