1. Applying Understanding: Conduction and Convection
Many tongues
have been
injured by
licking a piece
of metal on a
very cold day.
Why would no harm result if a piece of wood were licked on the same day?
 Applying Understanding: Conduction and Convection
Below are different situations that involve the principle of heat transfer in solids and fluids. Answer the questions and explain in terms of your understanding of heat transfer, specifically, conduction and convection.
The first question on the left is given as an example.
Metal is a good conductor of heat, the cold metal sucks heat so quickly from your tongue it can cause frost bite and damage the tissue of the tongue. However, wood is a poor conductor of heat.
If you hold one end of a metal nail against a piece of ice, the end in your hand soon becomes cold.
Does the cold flow from the ice to your hand? Explain.
Why do
cooks wear
oven gloves
when taking
food out of
the oven?
Explain how ‘firewalkers’
can walk
safely across
a bed of red-
hot coals in
bare feet.
Why is the
furnace
usually
in the
basement
of a house?
In a still room,
smoke from a
cigar will
sometimes rise
only so far, not
reaching the ceiling. Explain why.
Explain the two
methods of heat transfer that makes
a pot of water boil on a stove.
How does a blanket keep
you warm?
Does it
provide you
with heat?
How would placing a dented Ping-pong ball in boiling water remove the dent?

2. Applying Understanding: Conduction and Convection
Metal is a good
conductor of
heat, the cold
metal sucks heat
so quickly from your tongue it can cause frost bite and damage the tissue of the tongue.
 Applying Understanding: Conduction and Convection
Below are different situations that involve the principle of heat transfer in solids and fluids. Answer the questions and explain in terms of your understanding of heat transfer, specifically, conduction and convection.
The first question on the left is given as an example.
Metal is a good conductor of heat, the cold metal sucks heat so quickly from your tongue it can cause frost bite and damage the tissue of the tongue. However, wood is a poor conductor of heat.
Conduction.
No, cold does not flow. Heat flows from your hand to the nail to the ice. Since your hand is losing heat, it feels cold. HEAT is the only thing that flows.
Conduction
So, you don’t
get burnt.
Gloves
are poor
conductors of heat.
Because the rate of heat
transfer is slow, because
coals are not very good
conductors. If they walk
fast enough, there is only a small amount of heat transferred to their feet, and they do not burn.
Convection.
Furnace heats up cold air that has sunk to the bottom of the house. If it was at the top, it would be
Freezing at the lower
floors.
Convection
Smoke is initially hot.
Since hot air is less
dense than cool air it will rise. However, it will cool as it rises and density is the same as the density of the air in the room. At that point, it will stop rising.
Conduction and convection
A warm blanket does not provide you with heat; it simple slows the transfer of your body heat to the surroundings.
Conduction and Convection.
Boiling water transfers heat to ping pong ball and heats up air inside. Air expands and removes the dent.