Download Reading 21: Temperature, heat and expansion (pp 306-324)

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Reading 21: Temperature, heat and expansion (pp 306-324)
physics
1. Explain how the Celsius temperature scale is organized.
2.
Explain how the Fahrenheit temperature scale is organized.
3. What is meant by the phrase “absolute zero”?
4. Temperature is related to kinetic energy. Explain the surprising caption of
figure 21.2.
5. What is heat?
6. Heat flow is always in what direction?
7. If a thermometer “shows only its own temperature”, how can it be useful?
8. What’s the difference between heat and internal energy?
9. What’s the difference between a calorie and a Calorie?
10. Food labels often show the energy value in Calories. How is this number
determined?
11. In the Tour de France, a professional bicyclist may produce energy output of
400 watts (or 400 Joules per second). If he sustained this output for a 10 hour
ride, how many Calories would he need to eat? Show your work, using the factor
label, similar to the example on p. 312.
12. When you add heat to something, only some of the energy causes a
temperature increase. Name three other ways the added head can affect it.
13. How much heat is produced by a burning Cooler Ranch Dorito chip, if it
warms 150 g of water by 30oC? Show your work.
G=
U=
F=
S=
14. At the beach in August, the sun shines equally on sand and surf, and the
sand is hot but the water is not. Explain how this happens, using the concept of
specific heat capacity.
15. The Gulf Stream warms northern Europe, because the water had previously
warmed up in what location?
16. Of the three phases of matter, which one tends to expand the most when
heated?
Which expands the least?
17. Study figure 21.9. Why do bridges need expansion joints, while regular
roads don’t?
18. In the winter, your house cools down. How does the thermostat sense the
lower temperature, so it can start the heating system?
19. If a 50 cm long brass rod becomes 51 cm when heated by 20oC, what is its
ratio of expansion for 1oC?
20. At what temperature is water’s density the highest?
Why does water expand when cooled below this?
21. Explain why ice floats.