Question

A body $A$ of mass $1kg$ rests on a smooth surface. Another body $B$ of mass $0.2kg$ is placed over $A$ as shown. The coefficient of static friction between $A$ and $B$ is $0.15$. $B$ will begin to slide on $A$, if $A$ is pulled with a force greater than :

• A. $1.764N$
• B. $0.1764N$
• C. $0.3N$
• D. It will not slide for any $F$

Answer 1

The correct option is A $1.764N$

$B$ will begin to slide on $A$, if psuedo force is more than limiting friction

$F>F_1\Rightarrow m\left(\frac{F}{m+M}\right)>{\mu }_{0}mg$

$\Rightarrow m\left(\frac{F}{m+M}\right)>0.15mg$

$\therefore F>1.764N$