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NEETPhysicsCenter of Mass, Momentum and Collision

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): A projectile moving with velocity v explodes into two equal fragments. If one fragment is observed to move with velocity 3v , the other fragment must be moving with velocity v . Reason (R): The velocity of the center of mass of a system remains unchanged during an explosion because the forces of ex

Options

  1. ABoth Assertion and Reason are correct and Reason is the correct explanation for Assertion
  2. BBoth Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  3. CAssertion is correct but Reason is incorrect
  4. DAssertion is incorrect but Reason is correct

Correct answer

D. Assertion is incorrect but Reason is correct

Step-by-step solution

Evaluate Assertion (A): By conservation of linear momentum, the total initial momentum equals the total final momentum. Let the total mass of the projectile be m . m v = m 2 (3v) + m 2 v₂ v = 1.5v + 0.5 v₂ -0.5v = 0.5 v₂ v₂ = -v The other fragment must move with velocity -v , not v . Thus, the Assertion is incorrect. Evaluate Reason (R): During an explosion, the forces involved are purely internal. Since there is no net external force acting on the system, the acceleration of the center of mass is zero, and its vel

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