Question

In the arrangement shown in figure. The strings are light and inextensible. The surface over which blocks are placed is smooth. Find the acceleration of each block.

• A. $2m{s}^{-2}$
• B. $7m{s}^{-2}$
• C. $14m{s}^{-2}$
• D. $4.67m{s}^{-2}$

Answer 1

The correct option is A $2m{s}^{-2}$

Let $a$ be the acceleration of each block and $T_1$ and $T_2$ be the tensions, in the two strings as shown in the figure.

Taking the three blocks and the two strings as the system.
Using $\Sigma F_x=m{a}_x$
or $14=(4+2+1)a$
or $a=\frac{14}{7}=2m/s^2$