A) 81 cm/sec
B) 63 cm/sec
C) 144 cm/sec
D) None of these
Correct Answer: C
Solution :
Ratio in radius of steel balls = 1/2 So, ratio in their masses\[=\frac{1}{8}\] [As\[M\propto V\propto {{r}^{3}}\]] Let \[{{m}_{1}}=8m\] and \[{{m}_{2}}=m\] \[{{v}_{2}}=\frac{2{{m}_{1}}{{u}_{1}}}{{{m}_{1}}+{{m}_{2}}}=\frac{2\times 8m\times 81}{8m+m}=144\,cm/s\]You need to login to perform this action.
You will be redirected in
3 sec