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Dear student,

A v e r a g e V e l o c i t y = \frac{T o t a l d i s p l a c e m e n t}{T o t a l t i m e} \Rightarrow V_{a v g} = \frac{A B}{2} = \frac{\sqrt{2} R}{2} = \frac{\sqrt{2} R}{\sqrt{2} \times \sqrt{2}} = \frac{R}{\sqrt{2}}, O p t i o n 2

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