In the arrangement shown, the pulleys are fixed and ideal, the strings are light, $m_{1} > m_{2}$ and S is a spring balance which is itself massless. The reading of S (in units of mass) is -

Question

In the arrangement shown, the pulleys are fixed and ideal, the strings are light, m 1 ​ > m 2 ​ and S is a spring balance which is itself massless. The reading of S (in units of mass) is -

TestHub · Accepted Answer

Both masses together are connected by one string over the two fixed pulleys. For $m_{1} > m_{2}$ : $m_{1} g - T = m_{1} a$ and $T - m_{2} g = m_{2} a$ , so $a = \frac{( m _{1} - m _{2} ) g}{m _{1} + m _{2}}$ and $T = \frac{2 m _{1} m _{2} g}{m _{1} + m _{2}}$ .

The spring balance S is in the string and shows the tension $T$ ; in units of mass the reading is $T / g = \frac{2 m _{1} m _{2}}{m _{1} + m _{2}}$ .

Physics - NLM Question with Solution | TestHub

Options:

Doubts & Discussion