Q. A body of mass $1000\ kg$ is moving horizontally with a velocity $50\ m/s$. A mass of $250\ kg$ is added. Find the final velocity
A) $40\ m/s$
B) $20\ m/s$
C) $30\sqrt{2}\ m/s$
D) $50\ m/s$
Explanation
(a) $m_{1} = 1000\ kg.\ $ $v_{1} = 50\ m/s$, $m_{2} = 1250\ kg$, $v_{2} = ?$
From conservation law of linear momentum
$m_{1}v_{1} = m_{2}v_{2}$
$\Rightarrow 1000 \times 50 = 1250 \times v_{2} \Rightarrow v_{2} = 40\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.