Temperature-solutions

# Temperature-solutions - le(txl65 Temperature mohanty(81440...

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le (txl65) – Temperature – mohanty – (81440) 1 This print-out should have 13 questions. Multiple-choice questions may continue on the next column or page – fnd all choices beFore answering. 001 10.0 points A scuba diver has her lungs flled to halF capacity (5 L) when she is 14 m below the surFace. The acceleration oF gravity is 9 . 8 m / s 2 . IF the diver holds her breath while quietly rising to the surFace, what will be the volume oF her lungs (in liters) at the surFace? Correct answer: 11 . 86 L. Explanation: Given : ρ = 1000 kg / m 3 , V 2 = 1 × 10 5 kg / m 3 , V 1 = 5 L , and h = 14 m . We can take air as an ideal gas, so P V T = nR can be used to describe this process. Thus we have P 1 V 1 T 1 = P 2 V 2 T 2 , where the subscripts 1 and 2 stand For the initial and fnal states, respectively. Then the fnal volume can be expressed as V 2 = P 1 V 1 P 2 = ρ g h + P 2 P 2 V 1 = ρ g h P 2 V 1 + V 1 = ( 1000 kg / m 3 )( 9 . 8m / s 2 ) (14 m) 100 kPa (5 L) + (5 L) = 11 . 86 L , iF the temperature is constant during the pro- cess as in this problem. The pressure under the water is P 1 = P 2 + ρ g h = (1 × 10 5 kg / m 3 ) + (1000 kg / m 3 ) (9 . 8 m / s 2 ) (14 m) = 2 . 372 × 10 5 kg / m 3 , where P 2 is the pressure at the surFace; i.e. , the atmospheric pressure. 002 (part 1 of 2) 10.0 points A pendulum clock with a brass suspension system is calibrated so that its period is 1 s at 9 C. IF the temperature increases to 36 C, by how much does the period change? Correct answer: 0 . 000256467 s. Explanation: Given : t 1 = 1 s , T 1 = 9 C , T 2 = 36 C , and α = 1 . 9 × 10 5 ( C) 1 . The length changes by Δ L = αL 1 Δ T Δ L L 1 = α Δ T The period oF a pendulum is t 1 = 2 π r L 1 g . With the change in the length it becomes t 2 = 2 π r L 1 + Δ L g = 2 π r L 1 g p 1 + Δ L L 1 P = t 1 1 + α Δ T . 1 + α Δ T = R 1 + [1 . 9 × 10 5 ( C) 1 ] (27 C) = 1 . 00026 ,

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le (txl65) – Temperature – mohanty – (81440) 2 so the change in the period is Δ t = t p 1 + α Δ T - 1 P = (1 s) (1 . 00026 - 1) = 0 . 000256467 s . 003 (part 2 of 2) 10.0 points How much time does the clock gain or lose in one week? Correct answer: 155 . 111 s. Explanation:
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Temperature-solutions - le(txl65 Temperature mohanty(81440...

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