In a vessel, the gas is at a pressure P. If the mass of all the molecules is halved and their speed is doubled, then the resultant pressure will be:
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In a vessel, the gas is at a pressure P. If the mass of all the molecules is halved and their speed is doubled, then the resultant pressure will be:

G1 Physics · Accepted Answer

Step 1: Kinetic theory gives P = (1/3)(Nm/V)⟨v²⟩. Step 2: For fixed N and V, P ∝ m⟨v²⟩. Step 3: New molecular mass m′ = m/2; new speed v′ = 2v, so mean square speed becomes 4⟨v²⟩. Step 4: P′/P = (1/2) × 4 = 2. Final answer: (A) 2P.