Question

A horizontal force $F=2N$ is applied on the system shown in the figure. All surfaces are smooth. All pulleys and strings are ideal. Mass of blocks $A$ and $B$ each is $1kg$. What is the acceleration (in $m/s^2$) of $B$ with respect to $A$?

Answer 1

Step 1: Draw FBD of both blocks
For Block $A$

At both pulley tension is acting, and both are in opposite direction therefore block will be in equilibrium

For block $B$

Only single tension force is acting so it will be accelerating towards left

Step 2:Find force equation for block $B$
$F=T=ma$
$2=1\times a$
$a=2‘m/s^2$

FINAL ANSWER: $2$