assignment 9

course phys 202

1: 15.19 What is the maximum efficiency of a heat engine operating between temperatures of 380 C and 580 C?The formula used in order to find the max. efficiency of heat is tH-Tc/TH. After converting to Kelvin, 853-653/853=.23. If you take this answer and multiply it by 100, the percent would be 23%.

2. 5.26 source 550 C -> Carnot eff. 28%; source temp for Carnot eff. 35%?

Rearranging the equation to solve for tC (minimum) we get tC=823*(1-.28), tC=592K. Solving again for the maximum we get 912 K. After subtracting the maximum from the minimum temperature we get 639.