Question

A body of mass $50gm$ collides elastically with another body of mass $30gm$ at rest. Then the percentage loss of the velocity of the colliding body during collision is :

• A. 25%
• B. 75%
• C. 50%
• D. 67%

Answer 1

Answer: (B)

75%

Conserving momentum

$50\times V=50\times V_1+30\times V_2$

$e=\frac{V_2-V_1}{V}=1$

$V_2-V_1=V$

& $5V_1+3V_2=5V$

$\Rightarrow 8V_2=10V$

$V_2=\frac{10}{8}V$

$V_1=\frac{V}{4}$

$\%$ loss $=\frac{V-\frac{V}{4}}{V}\times 100$

$=75\%$