A) \[\frac{ev}{g}\]
B) \[\frac{{{e}^{2}}v}{g}\]
C) \[{{e}^{2}}\sqrt{\left( \frac{8h}{g} \right)}\]
D) \[{{e}^{2}}\sqrt{\left( \frac{h}{g} \right)}\]
Correct Answer: C
Solution :
Key Idea: Assume, initial velocity to be zero. From equation of motion \[h=ut+\frac{1}{2}g{{t}^{2}}\] when \[u=0,t=\sqrt{\frac{2h}{g}}\] The second impact occurs after an additional \[\text{time}=2\sqrt{2{{h}_{1}}g}=2e\sqrt{2h/g}\]\[(\because \,{{h}_{1}}={{e}^{2}}h)\] The third impact occurs after an additional \[\text{time}=2\sqrt{2{{h}_{2}}g}=2{{e}^{2}}\sqrt{2h/g}={{e}^{2}}\sqrt{8h/g}\] \[(\because \,{{h}_{2}}={{e}^{4}}h)\]
You need to login to perform this action.
You will be redirected in
3 sec
