Q. 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 1st mass is stationary, the velocity of the 2nd is
A) ${1\ ms}^{- 1}$
B) ${10\ ms}^{- 1}$
C) ${100\ ms}^{- 1}$
D) ${1000\ ms}^{- 1}$
Explanation
(c) $Given\ that,\ $
$v_{1} = 10\ {ms}^{- 1};\ \ m_{1} = 10\ kg$
$v_{2} = 0;\ m_{2} = 9\ kg$
$v_{3} = v;\ \ m_{3} = 1\ kg$
According to conservation of momentum
$m_{1}v_{1} = m_{2}v_{2} + m_{3}v_{3}$
$10 \times 10 = 9 \times 0 + 1 \times v \Longrightarrow v = 100\ {ms}^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.