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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 4 August 2021, Shift 2, Physics Q10

Question 10 of 90 in this shift, Physics question 10 of 30, Section A.

A body of mass ‘M’ is moving with a velocity ‘v’. It makes a one dimensional head on elastic collision with a stationary body of same mass. They are in contact for a very small time 'Δ\Deltat'. The contact force between them varies as shown in the figure. Find the magnitude of F‾max\overline{F}_{max} .

The figure, in words

Graph of F (vertical axis, with F_max marked) against t (horizontal axis, marked (t)): F rises linearly from the origin to F_max at t = Δt/4, then stays constant at F_max (dashed horizontal line) up to t = Δt (dashed vertical lines at Δt/4 and Δt).
  1. (1)mv7Δt\frac{mv}{7\Delta t}
  2. (2)8mv7Δt\frac{8mv}{7\Delta t}Official answer
  3. (3)7mv8Δt\frac{7mv}{8\Delta t}
  4. (4)mv8Δt\frac{mv}{8\Delta t}

Official answer

Option 2

NTA final key.

Chapter
System of Particles and Rotational Motion
Topic
Collisions
Idea tested
Impulse from Force-Time Graphs

Same topic in other shifts

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.