Thermodynamics packet

Completed Extra credit stamp

1. Sum Ch 21.1-4 & Q # 1-7 = 2

2. Heat Wkst = 2

3. Spec Heat Notes/Act = 2

4. Sum Ch 24.1-2 & Q # 1-8 = 2

5. Sum Ch 24.4-5 &Q #13-18,31 = 2

6. Sum Ch 24.6-7 &Q #19-25,32 = 2

7. 1st Law Notes = 1

8. 2nd Law Notes = 1

9. Study Guide = 3

10. Practice Written Q’s = 3

Total ______/20 +____

+Parent Signature __________________

Name ___________________________ Class __________________ Date ____________

Chapter 21 Temperature, Heat, and Expansion©

Pearson Education, Inc., or its affiliate(s). All rights reserved.

178 Conceptual Physics Reading and Study Workbook Chapter 21

Heat TransferA 50-gram strip of aluminum is heated to 100 C. It is then dropped into acontainer of water where it gives off 753 calories of heat. What is the finaltemperature of the aluminum? (The specific heat capacity of aluminum is0.215 cal/g C.)

1. Read and Understand

What information are you given?mass = m = 50 g

specific heat capacity = c = 0.215 cal/g C

initial temperature = Ti= 100 C

heat = Q = –753 cal

2. Plan and Solve

What unknown are you trying to calculate?final temperature = T

f

What equation can you use to find the unknown?Q = mc T = mc(T

f– T

i)

Rearrange the equation to solve for the unknown.

T Qmcf = Ti

Replace each variable with its known value.

T = 753 cal(50 g)(0.215 cal/g C)

C = 30 Cf 100

3. Look Back and Check

Is your answer reasonable? Because heat is given off (Q is a negative value), the final temperature

should be less than the original temperature, which it is. The answer isreasonable.

Math Practice

On a separate sheet of paper, solve the following problems.

1. A 35-gram piece of silver is dropped into a container of water. As it cools,the silver gives off 180 calories of heat. What is the silver’s temperaturechange? (The specific heat capacity of silver is 0.056 cal/g C.)

2. What mass of copper will give up 240 calories when its temperaturedrops from 90.0 C to 30.0 C? (The specific heat capacity of copper is0.092 cal/g C.)

Specific Heat Activity Summary:

Specific Heat capacity of water 4,187 J/KgCSpecific Heat capacity of vegetable oil 1,670 J/KgCSpecific Heat capacity of ocean water 3,930 J/KgC

Look at the above "c" values...What does that mean with respect to this lab? What should the results haveshown???

H2O#1

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1.

H2O#2

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2.

Oil

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3.

SUMMARY:

Define "c"

__________________________________________________________________________

Greater "c"

means...___________________________________________________________________

Lower "c" means...

___________________________________________________________________

Click Here to go to Activity-Summary Page (Click & scroll down to bottom of page)

CONCEPTUAL PHYSICS

Chapter 24 Thermodynamics 111

24-1Concept-DevelopmentPractice Page

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Thermodynamics

A mass of air is contained so that the volume can change but the pressure remains constant. Table I shows air volumes at various temperatures when the air is heated slowly.

1. Plot the data in Table I on the graph, and connect the points.

2. The graph shows how the volume of air varies with temperature at constant pressure. The straightness of the line means that the air expands uniformly with temperature. From your graph, you can predict what will happen to the volume of air when it is cooled.

Extrapolate (extend) the straight line of your graph to fi nd the temperature at which the volume of

the air would become zero. Mark this point on your graph. Estimate this

temperature:

3. Although air would liquify before cooling to this temperature, the procedure suggests that there

is a lower limit to how cold something can be. This is the absolute zero of temperature. Careful

experiments show that absolute zero is ˚C.

4. Scientists measure temperature in kelvins instead of degrees Celsius, where the absolute zero of

temperature is 0 kelvins. If you relabeled the temperature axis on the graph in Question 1 so that it

shows temperature in kelvins, would your graph look like the one below?

Name:______________________per._______

Conceptual Physics Chapter 21 & 24 Study Guide – Thermodynamics Essential Skills Questions:

1. Define temperature: ___________________________________________________________________

2. Use the properties of water to explain the differences between the Fahrenheit, Celsius and Kelvin scales:

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

3. Compare the Celsius and Kelvin scale with respect to absolute zero: _____________________________

____________________________________________________________________________________

4. Define Heat: _________________________________________________________________________

5. Define Internal Energy? ________________________________________________________________

6. Heat and Internal energy are both measured in __________________________________

7. What is the difference between temperature, heat, and internal energy??? _________________________

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

8. What is specific Heat capacity? __________________________________________________________

____________________________________________________________________________________

9. Why does water have a large specific heat capacity.? _________________________________________

____________________________________________________________________________________

10. Why does the sand change temperature so much while the ocean remains relatively the same temp? ___

____________________________________________________________________________________

11. If Reno, Nevada and Santa Cruz, California are about the same latitude, why is Santa Cruz typically

much more even temperature, whereas Reno can get very cold in the winter and quite hot in the

summer? ____________________________________________________________________________

____________________________________________________________________________________

12. One way to state the First law of Thermodynamics is to say that “______________ can neither be

_______________ or _________________”, which is basically a restatement of the Law of

_________________________ of Energy.

13. What is the equation for computing the efficiency of heat engines? ______________________________

14. Using the previous equation in order to increase efficiency you could either increase the _____________

or decrease the __________________.

15. What is the equation that we use for the work capabilities of a heat engine? _______________________

16. Write that equation as a sentence: ________________________________________________________

17. Work done on a system can increase the ___________________ and/or the _____________________.

18. Work is done to a system, can __________________________________________________________.

19. If a bicycle pump had NO FRICTION, would it get hot by pumping air? Explain why or why not. _____

____________________________________________________________________________________

20. If you put a chunk of hot gold into cold water, what would happen to the gold and what would happen to

the water? ___________________________________________________________________________

21. Define entropy? ______________________________________________________________________

22. Explain how entropy is related to the __________ Law of Thermodynamics: ______________________

____________________________________________________________________________________

23. What is the ideal efficiency of a heat engine that has a high temp of 3300J and a low of 300J? (show

work) ______________________________________________________________________________

24. How much work can be done by the same engine? ___________________________________________

25. Would it be possible to convert all that heat into work? Why or why not? ________________________

____________________________________________________________________________________

26. Explain how the energy of gasoline changes as it is used with respect to entropy: __________________

____________________________________________________________________________________

27. What does the book mean (p364) when it would say that the energy of the gasoline in the question above

becomes less organized? _______________________________________________________________

____________________________________________________________________________________

28. Use the “organization” of your bedroom as an example to help explain entropy: ___________________

____________________________________________________________________________________

29. Name one example from nature you could use as example of entropy and explain why it would be an

example: ____________________________________________________________________________

____________________________________________________________________________________

30. Show the proper equation and then solve for how many Joules of Heat energy are needed to raise the

temperature of 2 kilograms of water from 25 degrees Celsius to 35 degrees Celsius:_________________

____________________________________________________________________________________

31. What makes the “hero engine” spin? ______________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

32. If the water inside the hero engine is 100 degrees Celsius, how many Kelvins is that? _______________

33. How did you find that answer? __________________________________________________________

____________________________________________________________________________________

STAR exam questions:

1. Explain why putting a dented table-tennis ball in a pot of boiling water will help remove the dent.

2. Use the example of a barn to illustrate that natural systems tend to proceed toward greater entropy. Explain Entropy in your answer!

3. Give two reasons why a tire pump becomes hotter when used to pump a tire.

4. Use gasoline in your car as an example to explain that energy becomes less organized when it transformsfrom one form to another.

5. What amount of heat is required to raise the temperature of 150 grams of water by 20°C?

Heat and Thermodynamics exam Written Questions

For each of the following questions: ANSWER NEATLY AND COMPLETELY... Either show equation-substitution-solution or Write your answer in complete sentences.

6. Suppose you apply a flame and heat one liter of water and raise its temperature by 40°C. If you insteadtransfer the same quantity of heat to 8 liters of water at the same temperature, what will be the temperatureincrease?

7. An absolute temperature of 473 K is the same as what Celsius temperature?

8. Draw a table for both the Kelvin and Celsius temperatures for absolute zero, freezing point and boilingpoint of water.

9. The temperature of an object is raised by 70ºC. This is equivalent to what increase in its absolutetemperature? Briefly explain.

10. Calculate the ideal efficiency of a power plant that runs between temperatures 400 K and 150 K.

11. If 5000J of heat is added to a heat engine but only 3500J of work is done by the engine, what happens tothe remaining energy?

After you are done, click here to check your answers. Do not just click here and copy: A. that's cheating B. Copying is not learning and not learning leads to failing the exam. C. Truly studying requires forcing yourbrain to think, just like an exam forces your brain to think. Copying does not test your brain and your examanswer will suck if you copy.