Question

A body of mass 10 gm moving with a velocity of $20cm{s}^{-1}$ collides with a stationary mass of 90 gm. The collision is perfectly inelastic. Find the percentage loss of kinetic energy of the system.

• A. 0
• B. 50
• C. 90
• D. 100

Answer 1

Answer: (C)

90

Applying conservation of momentum.
$10\times 20=100\times v$
$v=2$ m/s

$\Delta K.E=\frac{1}{2}\times 10\times (20{)}^2-\frac{1}{2}\times 100\times (2{)}^2$

$=2000-200$
$=1800$

% loss $=\frac{1800}{\frac{1}{2}\times 10\times 400}\times 100$

$=\frac{1800}{2000}\times 100=90$