A) 1800 N
B) 2000 N
C) 2200 N
D) 2850 N
Correct Answer: A
Solution :
Key Idea: The bullet comes to rest inside the block, hence final velocity is zero. Let \[m\]be mass of bullet, travelling with initial velocity of \[120\,m/s(u).\] It comes to rest after travelling a distance of \[(0.12\,m=s)\] inside the block. Since, it comes to rest the final velocity \[(v)\] is zero. From equation of motion, we have \[{{v}^{2}}={{u}^{2}}+2as\] Here, \[v=0,u=120\,m/s,\,s=0.12\,m\] \[\Rightarrow \] \[a=-\frac{{{u}^{2}}}{2s}=\frac{{{(120)}^{2}}}{2\times 0.12}\] \[\Rightarrow \] \[a=-60,000\,m/{{s}^{2}}\] Resistive force \[F=ma\] \[\Rightarrow \] \[F=0.03\times 60,000\] \[F=1800\,N\]You need to login to perform this action.
You will be redirected in
3 sec