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Particle A of mass m_1 moving with velocity (√3 i+ j) ms^-1 collides with another particle B of mass m_2 which is at rest initially. Let v_1 and v_2…

JEE Main 2020 — Physics Mechanics

2020mcqhard

Particle AAA of mass m1{m}_{1}m1​ moving with velocity (3i^+j^)ms−1(\sqrt{3}\hat{i}+\hat{j}){\mathrm{ms}}^{-1}(3​i^+j^​)ms−1 collides with another particle BBB of mass m2{m}_{2}m2​ which is at rest initially. Let v⃗1{\vec{v}}_{1}v1​ and v⃗2{\vec{v}}_{2}v2​ be the velocities of particles AAA and BBB after collision respectively. If m1=2m2{m}_{1}=2{m}_{2}m1​=2m2​ and after collision v⃗1−(i^+3j^)ms−1{\vec{v}}_{1}-(\hat{i}+\sqrt{3}\hat{j}){\mathrm{ms}}^{-1}v1​−(i^+3​j^​)ms−1, the angle between v⃗1{\vec{v}}_{1}v1​ and v⃗2{\vec{v}}_{2}v2​ is :

Official previous-year question

Held on 6 Sept 2020 · Verified 6 Jul 2026.

Options

  1. A

    15∘{15}^{^{\circ}}15∘

  2. B

    60∘{60}^{^{\circ}}60∘

  3. C

    −45∘-{45}^{^{\circ}}−45∘

  4. D

    105∘{105}^{^{\circ}}105∘

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