Question

A $30g$ bullet initially traveling at $120m/s$ penetrates $12cm$ into wooden block. The average resistance exerted by the wooden block is

• A. $1800N$
  
• B. $2000J$
  
• C. $2200N$
  
• D. $1250N$
  

Answer 1

The correct option is A $1800N$

Given,

s= 12 cm= 0.12 m

v= 0 m/s

u= 120 m/s

Applying third equation of motion

$\Rightarrow 2as=v^2-u^2$

$\Rightarrow 2a\left(0.12\right)=0^2-{120}^2$

$\Rightarrow a=-60,000m/s^2$

$\Rightarrow ResistanceExerted=mass\times acceleration=0.03\times 60,000=1800N$

Hence correct answer is option $A$