Project TECHNOcean
Lesson/Activity Plan
Heat Transfer
Hayley Vatcher
Anna Reh-Gingerich
Murray Middle, 7th
Objective:
Students should be able to:
● Define and describe conduction
● Define and describe convection
● List some good conductors, and poor conductors
● Apply the concept of convection currents to a global scale with heat transfer in the
oceans and how it drives weather and climate
Curriculum Category:
● Conduction/Convection, 7th grade Physics
Materials:
● Blue & Red food coloring
● 3 cups per group
● Water
● Ice cubes for cold water source
● Heating element for hot water source
● Droppers
Procedure:
● Start by prepping hot and ice cold water in an area out of the way. Use a glass container
for the water, and have it on a heating element (hot plates are usually best). The other
container will have ice in it. Make sure to refresh ice as needed to keep the water as cold
as possible. Put plenty of blue food coloring in the ice cold water, and plenty of red food
coloring in the hot water.
● Introduction to heat transfer
○ Start with the concept of conduction and how molecules transfer heat by shaking
rapidly
■ Ask students which is hotter to the touch between a metal poker and a
wooden stick that have had one end sitting in a fireplace.
■ Discuss how there are good conductors and poor conductors. Ask
students to give some examples. Poor conductors are often known as
“insulators” since they help prevent heat loss.
■ Go through some examples of conduction in real-life, such as frying
bacon in a pan
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Lesson/Activity Plan
○
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Next, move on to the concept of convection and how it differs from conduction;
rather than the molecules shaking and transferring energy, it’s the movement of
the actual material transferring heat within itself through currents.
■ Discuss differential heating, one part of the material is heated or cooled
more than another.
Convection Activity
○ Break the students up into small groups and give each group three sets of cups,
all filled with room temperature water.
○ Have the students first write a hypothesis and some predictions on what they
think will happen in each of the three cups: one will receive hot water, one will
receive cold water, and the last one will receive both.
○ Next, give each group a dropper of hot water and tell them to write their
observations as they put the water in one of the cups.
○ Follow the same process for the second cup, but with cold water.
○ For the final cup, give the groups a dropper each of cold and hot water, and tell
them to add them into the same cup at the same time.
○ Once everyone has finished their own experiments, ask everyone to come
together for a large-scale presentation. Fill a large container (something like a
small aquarium works best) with room temperature water. Fill two cups, one with
hot water and cold water. You can ask the teacher to help you with the
demonstration. Have a countdown with the students, and pour one cup into each
side of the container (carefully!). Ask the students for observations as the waters
level out.
Global Implications
○ Show the students an image of deep ice formation and of global convection
currents. Talk about how water warms up by the equator, and then flows north
and south over the colder, denser water that flows towards the equator. Show
how it’s a repeating cycle. Discuss some of the major currents and how energy
can be released to surrounding areas, influencing climates. Weather is also
strongly driven by these currents.
Background:
Heat transfer can happen in a few different ways. The first major method is through conduction.
Conduction can be described as the transfer of heat between objects and molecules. When the
molecules become warmer, they begin to shake rapidly and pass heat to all of the molecules
nearby. Molecules in some materials are better conductors than others. For example, if a
wooden stick had one end sitting in a fire next to a metal poker, the metal poker would be much
hotter to the touch at the other end than the wooden stick. Most metals, such as copper,
aluminum, gold, etc. are good conductors. On the other hand, glass, porcelain, rubber, plastic,
Project TECHNOcean
Lesson/Activity Plan
and air are poor conductors and can be referred to as “insulators”. This is why rubber can often
be used to cover electrical wiring for power cords.
Another example of heat transfer is convection. Convection is different from conduction in that
the material itself moves to transfer the heat within itself. Therefore, convection is only possible
in liquids and gases. The other requirement for convection is that differential heating is involved,
meaning that one part of the material is heated or cooled more than another part. When a gas
or liquid is warmed, it becomes less dense and will rise above the cooler, denser parts of the
substance. Heat is released at the surface and as surface substance cools down, it will start to
sink again to be heated from the bottom and the cycle continues. This can be applied on a large
scale to the ocean systems. The equator is the part of the earth closest to the sun. The direct
sunlight warms the water substantially, creating a layer of lighter, warmer water. The warmer
water then flows away from the Equators towards the poles. Once the water nears the poles
and starts to encounter large sheets of ice and icebergs, it starts to cool down and become
more dense. It then sinks below the layer of lighter water and moves towards the equator. On
the map provided, it is possible to point out large-scale and smaller-scale currents. Convection
is largely responsible for major currents and drives climate and weather globally. It is known as
the “global conveyor belt”.
Supplemental Materials:
http://www.universetoday.com/82331/what-is-conduction/
http://en.wikipedia.org/wiki/Convection
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Lesson/Activity Plan
http://www.geography.hunter.cuny.edu/tbw/wc.notes/3.temperature/ocean_currents.htm
http://worldoceanreview.com/en/wor-1/climate-system/great-ocean-currents/
Project TECHNOcean
Lesson/Activity Plan
References Used:
Adapted from temperature_currents.pdf in dropbox folder, “Visit to an Ocean Planet:
Temperature and Deep Ocean Circulation”.
http://education-portal.com/academy/lesson/mechanisms-of-heat-transfer-conductionconvection-radiation.html#lesson