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Friday, 9 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumApplication

JEE Main 25 July 2021, Shift 1, Physics Q16

Question 16 of 90 in this shift, Physics question 16 of 30, Section A.

Two billiard balls of equal mass 30 g strike a rigid wall with same speed of 108 kmph (as shown) but at different angles. If the balls get reflected with the same speed then the ratio of the magnitude of impulses imparted to ball 'a' and ball 'b' by the wall along 'X' direction is :

The figure, in words

Ball (a) strikes the wall (line YY') perpendicularly along X'X with velocity u and rebounds along the same line. Ball (b) strikes the wall at point X at 45 degrees to the normal (45 degree angle marked between incoming ray and the X'X line) and is reflected symmetrically.
  1. (1)1:21:\sqrt{2}
  2. (2)1:11:1
  3. (3)2:12:1
  4. (4)2:1\sqrt{2}:1Official answer

Official answer

Option 4

NTA final key.

Chapter
Laws of Motion
Topic
Collisions
Idea tested
Oblique Wall Bounce

Same topic in other shifts

All Collisions questions
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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 42 of the 174 JEE Main shifts held from 2017 to 2026.