Question

In the figure below, all surfaces are assumed to be smooth and the force $F=100N$. If the acceleration of block $B$ of mass $20kg$ is '$a$' and tension in the string connecting block $A$ of mass $20kg$ is $T$, then just after force $F$ is applied,

• A. $T=0$ and $a=5m/s^2$
• B. $T=100N$ and $a=0$
• C. $T=200N$ and $a=5m/s^2$
• D. $T=100N$ and $a=5m/s^2$

Answer 1

The correct option is A $T=0$ and $a=5m/s^2$

As no force acts on $A$,
$T=0$
Acceleration of B
$a=\frac{F}{m_B}=\frac{100}{20}=5m/s^2$