Question

A string tired on a roof can bear a maximum tension of 50kg wt. The minimum acceleration that can be acquired by a man of 98 kg to descend will be [Take g = 9.8 m/s^2]​

Answer 1

Acceleration = $4.8 m/sec^2$

Explanation:

Suppose T  is the Tension in the string.

a is the acceleration of the descending man

tension opposes the weight,

$m g - T = m a$

$T = m (g - a)$

$a =   g - T/m$

If there is the maximum tension T then there will be minimum acceleration.  

$a = g  - 50 * \frac {g}{98}  = 4.8 m/sec^2$

Thus (3) $4.8 m/sec^2$ is correct answer.