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NEET
Exam
NEET
Subject
Physics
Chapter
Center of Mass, Momentum and Collision

NEET · Physics · Center of Mass, Momentum and Collision

Assertion (A): During collision between two objects, the momentum...

Assertion (A): During collision between two objects, the momentum of colliding objects is conserved only in direction perpendicular to line of impact. Reason (R): The force on colliding objects in perpendicular direction to line of impact is zero.

Options

  1. AAssertion (A) is True, Reason (R) is True; Reason (R) is a correct explanation for Assertion (A)
  2. BAssertion (A) is True, Reason (R) is True; Reason (R) is not a correct explanation for Assertion (A)
  3. CAssertion (A) is True, Reason (R) is False.
  4. DAssertion (A) is False, Reason (R) is True.

Correct answer

D. Assertion (A) is False, Reason (R) is True.

Step-by-step solution

Assertion (A): "During collision between two objects, the momentum of colliding objects is conserved only in direction perpendicular to line of impact." This is false. - In reality, linear momentum is conserved in all directions (because external force is absent). - What is special is that along the line of impact, momentum is not separately conserved for each object (because of impulsive forces), but the total system momentum is always conserved in both perpendicular and parallel directions. Reason (R): "The force on colliding objects in perpendicular direction to line of impact is zero." This is true. - Collision forces act only along the line of impact (normal at contact). - Therefore, perpendicular to line of impact, no impulsive force acts. (\checkmark) So the correct choice is: (4) Assertion (A) is False, Reason (R) is True. That matches the given answer key.
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