Question

Two bullets $P$ and $Q$, masses $10g$ and $20g$, are moving in the same direction towards a target with velocities of $20m/s$ and $10m/s$ respectively. Which one of the bullets will pierce a greater distance through the target ?

• A. $P$
• B. $Q$
• C. Both will cover the same distance
• D. Nothing can be decided

Answer 1

The correct option is A $P$

Let that target applied force F to both of the bullet P and Q.

then, deacceleration of $P=a_1=\frac{-F}{10}=\frac{-F}{10}$

deacceleration of $Q=a_2=\frac{-F}{20}=\frac{-F}{20}$

let P Penetrate x and Q Penetrate Y

then using en $V^2-u^2=2as$

For P

$0-{\left(20\right)}^2=2\left(\frac{-F}{10}\right)x$

$x=\frac{400\times 5}{F}=\frac{2000}{F}$

For Q

$0-{\left(10\right)}^2=2\left(\frac{-F}{20}\right)y$

$y=\frac{100\times 10}{F}=\frac{1000}{F}$

clear that x > y

So, Answer will be A.