A) \[\sqrt{\frac{h}{8g}}\]
B) \[\sqrt{8gh}\]
C) \[\sqrt{2gh}\]
D) \[\sqrt{\left( \frac{h}{2g} \right)}\]
Correct Answer: A
Solution :
For first stone\[v=0\]and For second stone\[\frac{{{v}^{2}}}{2g}=4h\]\[\Rightarrow \]\[{{u}^{2}}=8gh\] \[\therefore \] \[u=\sqrt{8gh}\] Now, \[{{h}_{1}}=\frac{1}{2}g{{t}^{2}}\] \[{{h}_{2}}=\sqrt{8ght}-\frac{1}{2}g{{t}^{2}}\] where, t=time to cross each other. \[\therefore \] \[{{h}_{1}}+{{h}_{2}}=h\] \[\Rightarrow \]\[\frac{1}{2}g{{t}^{2}}+\sqrt{8ght}-\frac{1}{2}g{{t}^{2}}=h\] \[\Rightarrow \] \[t=\frac{h}{\sqrt{8gh}}=\sqrt{\left( \frac{h}{8g} \right)}\]You need to login to perform this action.
You will be redirected in
3 sec