Question

Consider a situation as shown in figure. Find the minimum value of $m$ so that the blocks do not move.

• A. $2kg$
• B. $8kg$
• C. $10kg$
• D. $1kg$

Answer 1

The correct option is B $8kg$


For equilbrium,
$N=(10+m)g,T=6g$
Friction force,
$f=\mu N=\frac{1}{3}[10+m]g$
for the blocks to remain at rest,
$T=f$ and $f\le \mu N$
$\Rightarrow 6g\le \frac{(10+m)g}{3}\Rightarrow 18\le (10+m)\Rightarrow m\ge 8kg$