A) \[\sqrt{80}m/s\]
B) \[\frac{40}{\sqrt{2}}m/s\]
C) \[40m/s\]
D) \[40\sqrt{2}m/s\]
Correct Answer: D
Solution :
For first case, \[{{v}^{2}}={{u}^{2}}+2as\] \[\therefore \] \[0=(80)2+2\times 9\times 0.5\] \[\Rightarrow \] \[a=-6400\,\,m/{{s}^{2}}\] For second case,\[{{v}_{1}}^{2}={{u}^{2}}+2a{{s}_{1}}\] \[={{(80)}^{2}}-2\times 6400\times \frac{1}{4}\] \[=6400-3200=3200\] \[\therefore \] \[{{v}_{1}}=\mathbf{40}\sqrt{\mathbf{2}}\]You need to login to perform this action.
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