Two weights w 1 and w 2 are suspended from the ends of a light string passing over a smooth fixed pulley. If the pulley is pulled up with acceleration g , the tension in the string will be

Question

TestHub · Accepted Answer

For solving the problem, we assume that observer is situated in the frame of pulley (non - inertial reference frame).

$m_{1} g = w_{1}$

$m_{2} g = w_{2}$

From force diagram [a],

$T - m_{2} a_{0} - w_{2} = m_{2} a$

Or $T - m_{2} g - w_{2} = m_{2} a$ $(∵ a_{0} = g)$

Or $T - 2 w_{2} = m_{2} a$ .....(i)

From force diagram [b],

$m_{1} a_{0} + w_{1} - T = m_{1} a$

Or $m_{1} g + w_{1} - T = m_{1} a$ $(∵ a_{0} = g)$

Or $2 W_{1} - T = m_{1} a$ ......(ii)

From equations (i) and (ii),

$T = \frac{4 w_{1} w_{2}}{w_{1} + w_{2}}$

Physics - NLM Question with Solution | TestHub

Options:

Doubts & Discussion