A) \[u\]
B) \[2u\]
C) \[u-gt\]
D) \[\sqrt{({{u}^{2}}-gt)}\]
E) \[gt\]
Correct Answer: A
Solution :
From equation of motion, we have \[v=u+gt\] where u is initial velocity and t is time. For ball A, \[{{v}_{A}}=u-gt\] For ball B, \[{{v}_{B}}=0+gt\] \[\therefore \] Relative speed, \[\Delta \overrightarrow{v}={{\overrightarrow{v}}_{A}}-{{\overrightarrow{v}}_{B}}\] \[=(u-gt)\hat{j}-(-gt\,\hat{j})\] \[=u\hat{j}\]You need to login to perform this action.
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