Question

Figure shows a man of mass $50kg$ standing on a light weighing machine kept in a box of mass $30kg$. The box is hanging from a pulley fixed to the ceiling through a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, the weight shown by the machine is:-

• A. $100N$
• B. $200N$
• C. $50N$
• D. $300N$

Answer 1

The correct option is A $100N$

$\begin{array}{c}\text{Correct option is}\left(A\right)\\ \text{on box + man system}\Rightarrow \\ \begin{array}{cc}2T& =(M+m_1)g\\ 2T& =800\\ T& =400N\\ \text{On man};& N+m_{1}g=T\\ & N+300=400\\ & N=100\text{Newton}\end{array}\end{array}$