Q.
If the mass of $A = 10$ kg, coefficient of static friction $= 0.22,$ coefficient of kinetic friction $= 0.2,$ then minimum mass of $B$ to start motion is
A) 2 kg
B) 2.2 kg
C) 4.8 kg
D) 3.4 kg
Explanation
(b) Let the minimum mass of B is $M_{B}.$
Force applied by it $F = M_{B}g$
Friction force on block $A$
$f = \mu\ M_{A}g$
For motion to start
$M_{B}g = \mu\ M_{A}g$
$M_{B} = 0.22 \times 10$
$= 2.2$ kg
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.