A man (mass = 50 , kg) and his son (mass = 20 , kg) are standing … - Vidyadip

MCQ

A man (mass $= 50\, kg$) and his son (mass $= 20\, kg$) are standing on a frictionless surface facing each other. The man pushes his son so that he starts moving at a speed of $0.70\, ms^{-1}$ with respect to the man. The speed of the man with respect to the surface is ........ $ms^{-1}$

A
$0.47$
B
$0.28$
C
$0.14$
✓
$0.20$

✓

Answer

Correct option: D.

$0.20$

d
$\begin{array}{l}
\Rightarrow 0 = 50{V_1} - 20{V_2}\,and\,{V_1} + {V_2} = 0.7\\
\Rightarrow \,{V_1} = 0.2
\end{array}$

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