Sp09-MT1-Huang-Soln - Problem 3 Part A: In this...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Problem 3 Part A: In this configuration, the heat output of the first engine is the heat input of the second engine. Let e 1 = 1 2 ( 1- T 2 T 1 ) and e 2 = 1 2 ( 1- T 4 T 3 ) be the efficiencies of the first and second engines respectively. Note that each engine is operating at 50% of its Carnot efficiency, as stated in the problem. Q H 1 = W 1 + Q L 1 W 1 = e 1 · Q H 1 ⇒ Q L 1 = ( 1- e 1 ) · Q H 1 W 2 = e 2 · Q H 2 = e 2 · Q L 1 = e 2 · ( 1- e 1 ) · Q H 1 W total = W 1 + W 2 = ( e 1 + e 2- e 1 · e 2 ) Q H 1 Let r be the rate at which coal is being burned. Then Δ Q H 1 Δ t = rb . p = Δ W total Δ t = ( e 1 + e 2- e 1 · e 2 ) · Δ Q H 1 Δ t ⇒ p = ( e 1 + e 2- e 1 · e 2 ) · rb ⇒ r = p ( e 1 + e 2- e 1 · e 2 ) · b = 122 kg s Part B: For this part, we’ll look at the engine as a whole and apply the first law of thermodynamics. Q in = W + Q out ⇒ Δ Q in Δ t = Δ W Δ t + Δ Q out Δ t ⇒ rb = p + Δ Q out Δ t = p + Δ Q W Δ t ⇒ Δ Q W Δ t = rb- p = 2665 MW Part C: 1 Q = mc Δ T ⇒ Δ Q W Δ t = Δ m Δ t c W Δ T ⇒ Δ m Δ t = Δ Q W Δ t m W Δ T = 106000 kg s 2 1 1 Huang, Spring 2009 Problem 4 (25 points) An ideal monoatomic gas in a thermally insulated box is separated by a thermally conducting partition into two parts. There are n moles of gas in each part. Initially the gas in part A has temperature T 1 and ovlume V 1 and in B temperature T 2 and volume V 2 . The partition can slide without friction and the two parts have the same pressure, P . (a) (10 pts.) What is the final temperature when thermal equilibrium is reached?...
View Full Document

This note was uploaded on 02/09/2010 for the course PHYSICS 7B taught by Professor Packard during the Spring '08 term at University of California, Berkeley.

Page1 / 9

Sp09-MT1-Huang-Soln - Problem 3 Part A: In this...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online