Question

A free body of mass 8 kg is travelling at 2 metres per second in a straight line. At a certain instant, the body splits into two equal parts due to internal expolsion which releases 16 joules of energy. Finally

• A. Both parts continue to move in the same direction as that of the oritinal body
• B. One part comes to rest and the other moves in the same direction as that of the original body.
• C. One part comes to rest and the other moves in the direction opposite to that of the original body.
• D. One part moves in the same direction and the other in the direction opposite to that of the original body.

Answer 1

The correct option is B One part comes to rest and the other moves in the same direction as that of the original body.

From the law of conservation of momentum,
$8\times 2=4V_1+4V_2$
$\Rightarrow V_1+V_2=4$
From the law of conservation of energy, taking into account the 16 J energy released into the system,
$16+\frac{1}{2}\times 8\times 4=\frac{1}{2}\times 4\times V_1^2+\frac{1}{2}\times 4\times V_2^2$
$\Rightarrow V_1^2+V_2^2=16$
On solving,
$V_1=0,V_2=4$