Two particles A ,   B are moving on two concentric circles of radii R 1 and R 2 with equal angular…

Two particles A, B are moving on two concentric circles of radii R1 and R2 with equal angular speed ω. At t=0, their positions and direction of motion are shown in the figure:

The relative velocity VA→-VB→ at t=π2ω is given by:

  1. $\vec{V}_{A} - \vec{V}_{B} = \omega | R_{1} | \hat{i}$
  2. $\vec{V}_{A} - \vec{V}_{B} = \omega | R_{2} | \hat{i}$
  3. $\vec{V}_{A} - \vec{V}_{B} = \omega | R_{2} + R_{1} | \hat{i}$
  4. $\vec{V}_{A} - \vec{V}_{B} = \omega | R_{2} - R_{1} | \hat{i}$

Solution

t=π2ω

V→A=ωR1-i^

V→B=ωR2-i^

VA→-VB→=ωR2-R1i^

Asked in: JEE Main 2019 (12 Jan Shift 2)

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