Question

The ball starts falling from some height. After falling height $h$ , it breaks into two parts $m_{1}$ and $m_{2}$ . Finally, they reach the earth surface. Choose the correct option.

• A. $R$ will depend on $h$
• B. If $m_{1}>m_{2}$ , then $x_{1} < x_{2}$
• C. The centre of mass of the two balls (system) will shift towards the heavier part
• D. None of the above

Answer 1

Answer: (B)

If there is no external force acting then linear momentum of system will be conserved.
From conservation of momentum theorem, the $X$ component of momentum is conserved
So, $m_{1} V_{1}=m_{2} V_{2}$
$\Rightarrow R$ will not depend on the vertical height $h$.
if $m_{1}>m_{2}$
Then, $v_{1}< v_{2}$
So, $x_{1}< x_{2}$
The CM of the system of two balls will lie on the same vertical line. It will come down vertically due to gravitational force but it will not move horizontally as $\left(F_{\text {ext }}\right)_{x}=0$