Question

A shell of mass 20 kg at rest explodes into two fragments whose masses are in the ratio 2 : 3. The smaller fragment moves with a velocity of 6 m/s. The kinetic energy of the larger fragment is

• A. 96 J
• B. 216 J
• C. 144 J
• D. 360 J

Answer 1

The correct option is A 96 J

The masses of smaller and larger pieces be $8kg,12kg$ respectively.

By conservation of momentum

$0=8\times 6+12\times v$

$\Rightarrow V=-4m{s}^{-1}$

Here minus sign indicates that it is in opposite direction.

Kinetic energy of larger fragment $=\frac{1}{2}m{v}^2=96J$