Question

A bullet on penetrating $30cm$ into its target loses its velocity by $50$%. What additional distance will it penetrate into the target before it comes to rest?

• A. $30cm$
• B. $20cm$
• C. $10cm$
• D. $5cm$

Answer 1

Answer: (C)

$10cm$

Given: $S=30cm=30\times {10}^{-2}m$ and loss in velocity is $50$%
Equation of motion:
$v^2=u^2+2as$
Here, $\frac{u^2}{4}=u^2+2a\times 30\times {10}^{-2}$ ...... (i)
$0=\frac{u^2}{4}+2a\times x$ ......... (ii)
On solving Eqs. (i) and (ii), we get
$x=10cm$