A) 49 cm/s
B) 98 cm/s
C) 147 cm/s
D) 196 cm/s
E) 208 cm/s
Correct Answer: B
Solution :
Rate of change of momentum of bullets = weight of disc i.e., \[m\frac{dv}{dt}=mg\] \[5\times {{10}^{-3}}\times 10\,[v-(-v)]=10\times {{10}^{-3}}\times 9.8\] \[5(2v)=9.8\] \[v=\frac{9.8}{10}m\text{/}s\] \[=\frac{9.8}{10}\times 100\,cm\text{/}s\] \[=98\,cm\text{/}s\]You need to login to perform this action.
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