1. Chapter Pretest

2. 1. A 3. 00 x 10-3 kg lead bullet travels at a speed of 2
1. A 3.00 x 10-3 kg lead bullet travels at a speed of 2.40 x 102 m/s and hits a wooden post. If half the heat energy generated remains with the bullet, what is the increase in temperature of the embedded bullet? (clead = 128 J/kg•°C) a. 112°C b. 137°C c. 225°C d. 259°C

3. 1. A 3. 00 x 10-3 kg lead bullet travels at a speed of 2
1. A 3.00 x 10-3 kg lead bullet travels at a speed of 2.40 x 102 m/s and hits a wooden post. If half the heat energy generated remains with the bullet, what is the increase in temperature of the embedded bullet? (clead = 128 J/kg•°C) a. 112°C b. 137°C c. 225°C d. 259°C

4. 2. What is the temperature increase of 4 kg of water when it is heated by an 800 W immersion heater for exactly 10 minutes? (cwater = 4186 J/kg•°C) a. 57°C b. 51°C c. 29°C d. 14°C

5. 2. What is the temperature increase of 4 kg of water when it is heated by an 800 W immersion heater for exactly 10 minutes? (cwater = 4186 J/kg•°C) a. 57°C b. 51°C c. 29°C d. 14°C

6. 3. Over several cycles, a refrigerator does 1
3. Over several cycles, a refrigerator does 1.73 x 104 J of work on the refrigerant. The refrigerant removes 8.11 x 104 J as heat from the air inside the refrigerator. How much energy is delivered to the outside air? a x 104 J b x 104 J c x 104 J d x 104 J

7. 3. Over several cycles, a refrigerator does 1
3. Over several cycles, a refrigerator does 1.73 x 104 J of work on the refrigerant. The refrigerant removes 8.11 x 104 J as heat from the air inside the refrigerator. How much energy is delivered to the outside air? a x 104 J b x 104 J c x 104 J d x 104 J

8. 4. An engine absorbs 2150 J as heat from a hot reservoir and gives of 750 J as heat to a cold reservoir during each cycle. How much work is done during each cycle? a. 750 J b J c J d J

9. 4. An engine absorbs 2150 J as heat from a hot reservoir and gives of 750 J as heat to a cold reservoir during each cycle. How much work is done during each cycle? a. 750 J b J c J d J

10. 5. A heat engine performs 2000. 0 J of net work while adding 5000
5. A heat engine performs J of net work while adding J of heat to the cold-temperature reservoir. What is the efficiency of the engine? a b c d

11. 5. A heat engine performs 2000. 0 J of net work while adding 5000
5. A heat engine performs J of net work while adding J of heat to the cold-temperature reservoir. What is the efficiency of the engine? a b c d

12. 1. Why is air an effective thermal insulator for the body?

13. Because air is such a poor thermal conductor.

14. 2. A mixture of 30. 2 g of sand and 87
2. A mixture of 30.2 g of sand and 87.7 g of water has a temperature of 12.1°C. What mass of water at 85.8°C must be added to raise the final temperature of the mixture to 29.3°C? (cwater = 4.19 J/g•°C and csand = 2.01 J/g•°C)

15. cm∆T + cm∆T = cm∆T 2. 01(30. 2)17. 2 + 4. 19(87. 7)17. 2 =. 4. 19(m)56
cm∆T + cm∆T = cm∆T 2.01(30.2) (87.7)17.2 = (m)56.5 m = 31.1 g