5.14 Heat Conduction
http://www.hk-phy.org/contextual/heat/hea/condu/conduction_e.html
In the opening photo above, conduction occurs between particles of metal in the cookie sheet and anything cooler
that comes into contact with it—hopefully, not someone’s bare hands! For a deeper understanding of this method of
heat transfer, watch the animation “Conduction” at this URL:
http://www.sciencehelpdesk.com/unit/science2/3
Examples of Conduction
The cookie sheet in the opening image transfers thermal energy to the cookies and helps them bake. There are
many other common examples of conduction. TheFigure5.29 shows a few situations in which thermal energy is
transferred in this way.
FIGURE 5.29
Hot Iron: A hot iron removes the wrinkles
in a shirt. Hot Cocoa: Holding a cup of
hot cocoa feels good when you have cold
hands. Camp Stove: This camp stove
can be used to cook food in a small pot.
Snow: Ouch! Can you imagine how cold
this snow must feel on bare feet?Q:How is thermal energy transferred in each of the situations pictured in theFigure5.29?
A:Thermal energy is transferred by conduction from the hot iron to the shirt, from the hot cup to the hand holding it,
from the flame of the camp stove to the bottom of the pot as well as from the bottom of the pot to the food inside, and
from the feet to the snow. The shirt, hand, pot, food, and snow become warmer because of the transferred energy.
Because the feet lose thermal energy, they feel colder.