Question bank/JEE Main/Physics

JEE MainPhysicsHardRelative motion

Two particle A and B are located in x-y plane at points (0, 0)
and (0, 4 m). They simultaneously start moving with velocities.

v→A=3j^m/s{\overset{\rightarrow}{v}}_{A} = 3\overset{\hat{}}{j}m/sand
v→B=4i^m/s{\overset{\rightarrow}{v}}_{B} = 4\overset{\hat{}}{i}m/s. The shortest
distance between them will be

Show answer and solution
Assuming B to be at rest, A will move with velocity
v→AB{\overset{\rightarrow}{v}}_{AB} in the direction shown in figure. The
distance between them will first decrease from A to Cand then increase

beyond C.

[IMAGE] Minimum distance between them is BC which is equal to

4 sin53∘=16/5m4\ sin53^{\circ} = 16/\mathbf{5}\mathbf{m}

Source: Grass-G / P-05 Physics paper 10 October.docx

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