A) \[40\sqrt{2}\]
B) \[40\sqrt{3}\]
C) \[25\sqrt{3}\]
D) 45
Correct Answer: B
Solution :
Initial moment of the body in vertical upward direction \[{{p}_{1}}=mv\cos {{30}^{o}}\] \[=\frac{\sqrt{3}}{2}mv\] Final momentum of body in downward direction \[{{p}_{2}}=mv\cos {{30}^{o}}\] \[=\frac{\sqrt{3}}{2}mv\] Change in momentum \[\Delta {{p}_{2}}={{p}_{2}}-(-{{p}_{1}})\] \[={{p}_{2}}+{{p}_{1}}\] \[=\frac{\sqrt{3}}{2}mv+\frac{\sqrt{3}}{2}mv\] \[=\sqrt{3}\,mv\] \[=\sqrt{3}\times 2\times 20\] \[=40\sqrt{3}\]You need to login to perform this action.
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