Heat, Temperature,

1
Chapter 21

• Heat, Temperature, Thermal Expansion

2
Temperature

• What is temperature?
• How is it measured?
• What are the three common temperature scales?
• What is the freezing and boiling point of water
  on each of these scale?
• Which scale is most precise? Why?

3
Heat

• What is heat?
• Which has more internal energy a warm bucket of
  water or a hot cup of coffee?
• How does heat flow?
• What is thermal equilibrium?

4
Specific Heat Capacity

• What is specific heat capacity?
• Does water have a high or low specific heat?
• Why is weather more mild (temperatures stay about
  the same all year long) in San Francisco than
  Washington, DC?

5
Specific Heat Capacity

• What happens the temperature of a substance when
  heat is added?
• ? Q mc?T

6
Specific Heat Capacity

• If 100 calories of heat are added to 5 grams of
  10C water, what is the final temperature of the
  water? (the specific heat of water 1 cal/gC)
• Gwyns bowl is filled with 175 g of 60.0ºC soup
  (mostly water) that she stirs with a 20.0ºC
  silver spoon with a mass of 40 g. The spoon
  slips out of her hand and slides into the soup.
  What equilibrium temperature will be reached if
  the spoon is allowed to remain in the soup and no
  heat is lost to the outside air? (cspoon .057
  cal/gºC, cwater 1 cal/gºC) Assume that the
  temperature of the bowl does not change.

7
Thermal Expansion

• What happens to the volume of an object when heat
  is added?
• If a ring (or an object with a hole) is heated,
  what happens to the size of the hole?

8
Thermal Expansion

• Linear
• Area
• Volume
• The Eiffel Tower, constructed in 1889 by
  Alexandre Eiffel, is an impressive latticework
  structure made of iron. If the tower is 301 m
  tall on a 22C day, how much does its height
  decrease when the temperature cools to 0C? (The
  coefficient of linear expansion of iron is 12 x
  10-6 C-1)