Question

If a body looses half of its velocity on penetrating $3$ cm in a wooden block, then how much will it penetrate more before coming to rest?

• A. $1cm$
• B. $2cm$
• C. $3cm$
• D. $4cm$

Answer 1

The correct option is A $1cm$

$v^2=u^2+2as,$
${\left(\frac{u}{2}\right)}^2=u^2-2a\left(0.03\right)$

$0.06a=u^2(1-\frac{1}{4})\Rightarrow u^2=0.06a\times \frac{4}{3}$
$v^2=u^2+2as\Rightarrow 0=u^2-2as$

$0.06a\frac{4}{3}=2as$
$s=0.04m$
$=4cm$
Distance it will travel further =$3cm$