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Correct Answer: Option (B) — Both A and R are true but R is not a correct explanation of A
Concept & Option Breakdown
Standard Reference VerifiedAssertion (A) is true: When a person whistles, air is expelled with forward momentum. By conservation of momentum / Newton's third law (action-reaction), an equal and opposite backward momentum is imparted to the person, propelling them backward on the frictionless surface. Reason (R) is true: Law of conservation of linear momentum states that total momentum remains constant in the absence of external forces. However, Reason (R) states Newton's first law/conservation of system momentum, while the explanation for self-propulsion rests on the internal mass expulsion and Newton's Third Law.
Both statements are individually valid physical principles, but R represents the general conservation law rather than explaining how expelled air creates thrust.
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