Question

Two man of mass $50 \, kg$ and $60 \, kg$ on diametrically opposite point of a turntable of mass $90 \, kg$ . The turntable is free to rotate about vertical axis. The two men start moving towards each other along the circumference of table. The angle rotated by table when the two men meet each other -

• A. $8.2^\circ $
• B. $4.5^\circ $
• C. $2.8^\circ $
• D. $6.8^\circ $

Answer 1

Answer: (B)

Let $‘\theta ’$ be angle rotated by turntable
Let mass of man $1=m_{1} \, \left(= 50 \, k g\right)$
Let mass of man $2=m_{2} \, \left(= \, 60 \, k g\right)$
Let mass of $turntable=m \, \left(= \, 90 \, k g\right)$


$\therefore m _{1}\left(90^{\circ}+\theta\right)+ m _{2}\left\{-\left(90^{\circ}-\theta\right)\right\}+ m \cdot \theta=0$
$\Rightarrow \theta=4.5^{\circ}$