1. Tardigrade
  2. Question
  3. Physics
  4. A bullet of mass 40 g moving with a speed of 90 m s-1 enters a heavy wooden block and is stopped after a distance of 60 cm. The average resistive force exerted by the block on the bullet is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A bullet of mass $40 \,g$ moving with a speed of $90\, m s^{-1}$ enters a heavy wooden block and is stopped after a distance of $60 \,cm$. The average resistive force exerted by the block on the bullet is

NEETNEET 2022Laws of Motion

Solution:

Here, $u=90 \,m \, s^{-1},$ $v=0$
$m=40 \,g$ $=\frac{40}{1000} kg$ $=0.04\, kg,$ $s=60\, cm$ $=0.6\, m$
using $v^{2}$ $-u^{2}$ =$2 as$
$\therefore $ $\quad\quad\left(0\right)^{2}$ $-\left(90\right)^{2}$ $=2a\times0.6$
$\quad\quad a=-\frac{\left(90\right)^{2}}{2\times0.6}$ $=-6750\, m s^{-2}$
$-ve$ sign shows the retardation.
$\quad\therefore \quad$ The average resistive force exerted by block on the bullet is
$\quad F=m\times a$ $=\left(0.04 \, kg\right)$ $\left(6750\,ms^{-2}\right)$ $=270 \, N$