A) 2 m/s
B) 4 m/s
C) 8 m/s
D) 0.2 m/s
Correct Answer: A
Solution :
Key Idea: Linear momentum of a system is conserved in absence of any external force. Conservation of linear momentum gives \[{{m}_{1}}\,\,{{u}_{1}}+\,{{m}_{2}}\,{{u}_{2}}=({{m}_{1}}+{{m}_{2}})\,v\] Given, \[{{m}_{2}}=25\,g,\,{{u}_{1}}=400\,m/s\] \[{{m}_{2}}=4.9\,kg,\,{{u}_{2}}=0\,,v=?\] Hence, \[\frac{25}{1000}\times 400+4.9\times 0=\left( \frac{25}{1000}+4.9 \right)v\] or \[v=\frac{10000}{4925}\approx 2\,m/s\] Note: Since, bullet is embedded into bag hence the collision is inelastic. But still the momentum is conserved.
You need to login to perform this action.
You will be redirected in
3 sec
