Question

A block of mass $1kg$ is connected by a light string passing over two smooth pulleys placed on a smooth horizontal surface as shown. Another block of $1kg$ is connected to other end of the string then acceleration of the system and tension in the string are:

• A. $5{ms}^{-2},5N$
• B. $1{ms}^{-2},1N$
• C. $1{ms}^{-2},5N$
• D. $5{ms}^{-2},10N$

Answer 1

Answer: (A)

$5{ms}^{-2},5N$

For block on the horizontal surface, $T=ma=a....\left(1\right)$
For hanging block, $ma=mg-T\Rightarrow a=g-a$
$2a=10\Rightarrow a=5m/s^2$ (take $g=10$)
$\therefore T=5N$