Question

A shell of mass $10\, kg$ is moving with a velocity of $10\,ms^{-1}$ when it blasts and forms two parts of mass $9 \,kg$ and $1 \,kg$ respectively. If the $1^{st}$ mass is stationary, the velocity of the $2^{nd}$ is

• A. 1 m/s
• B. 10 m/s
• C. 100 m/s
• D. 1000 m/s

Answer 1

Answer: (C)

100 m/s

Answer 2

Given that $v_{1}=10\, m / s ; m_{1}=10\, kg$
$v_{2}=0 ; m_{2}=9\, kg$
$v_{3}=v ; m_{3}=1\, kg$
According to conservation of momentum
$m_{1} v_{1}=m_{2} v_{2}+m_{3} v_{3}$
$10 \times 10=9 \times 0+1 \times v$
$\Rightarrow v=100\, m / s$