## PHYSICS II HOMEWORK

## CHAPTER 15 HOMEWORK: THERMODYNAMICS

**Resources:**

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**Question 1**

**Explanation**

Part A U=Q-W “Isothermal” means no change in temp. U=change in temp. Therefore U = 0 Part B 0 = x – 2.7e3 x= 2.7e3

**Question 2**

**Explanation**

e = W / Q = W / W + Q_{L} = 2100 / (2100 + 9200) = .1858 = 18.58%

**Question 3**

**Explanation**

the efficiency is given by E = (Tw – Tc) / Tw where T is absolute temperature:w for warm & c for cold *Remember to convert your temperatures to Kelvin by adding 273 to each.

**Question 4**

**Explanation**

To find total heat generated: (.39)(x) = 570 x = 1461.54 Total heat generated – heat put out= heat discharged 1461.54 – 570 = 891.54

**Question 5**

**Explanation**

275.5 / (295 – 275.5) = 14.13 *Remember to convert to Kelvin