Transcript Heat Transfer and the Movement of Air

Heat Transfer and the Movement of Air
moves ?
Heat Transfer and the Movement of Air
Inquiry 4.2
Big Question:
How do you think the temperature of the air
affects how air moves?
Hypothesis:
Answer the Big Question. How do you think
the air will move above a cold surface? Hot
Surface?
Heat Transfer and the Movement of Air Inquiry 4.2
Materials:
Convection
Tubes (2)
Punk Stick
Hot water
Funnel
Cold Water
(ice)
Tubing
Aluminum Pan
Flashlight
Heat Transfer and the Movement of Air Inquiry 4.2
Procedures:
1.
Gather materials needed. Set up Convection Tubes with hot and cold
water as you did in Inquiry 4.1. (You will not be recording temp change in
this investigation)
2.
Attach tubing and funnel to the convection Tube with cold water (very
important to start with cold water).
3.
Take the punk stick (after the teacher has lit the stick and blown out the
flame) and hold it over the aluminum pan. Hold the funnel at an angle over
the punk stick so that the smoke goes inside. (Do not touch the funnel with
the burning punk stick.
4.
Use your flashlight to observe how the smoke moves within the Convection
Tube. Hold the flashlight at the side of the Convection Tube, then at the
top of it (do not cover the opening of the Convection Tube ). Talk with
your group about how the smoke moves.
5.
Move tubing and funnel to the convection tube with hot water, repeat steps
#3 & #4. When you have finished observing the Convection Tube with hot
water, clean up. Carefully put out the punk stick in the aluminum pan.
Heat Transfer and the Movement of Air Inquiry 4.2
Observations/Data/Results
Observation notesHow did the smoke move within the Convection Tube with:
Cold water (ice) -
Hot water –
Conclusion
1) Restate the Big Question.
2) Revisit your original hypothesis.
Heat Transfer and the Movement of Air Inquiry 4.2
Reflection Questions
1. On the basis of your temperature readings in Inquiry 4.1 how
does the temperature of a surface affect the temperature of
the air above it?
2. How did the air, which was visible because of the smoke, move
in the Convection Tube when the water under it was cold?
Explain why you think this happened.
3. What happened to the air inside the Convection Tube when
the water was hot? Explain why you think this happened
4. Why do you think moisture formed on the inside of the
Convection Tube with hot water? How do you think this
relates to cloud formation on the earth?
Conclusion Example
The temperature of the air affects how air moves because
Cold air is more dense so it sinks whereas warm air
Is less dense and it rises. My original hypothesis stated that
Warm air rises and during the investigation when we used
Hot water to warm the air the smoke quickly move through
the top of the convection tube. The smoke/air was thin and
wispy. The cold air did not move as quickly and it dropped
Down near the cold water(surface), showing that cold air is
More dense so it sinks.
Reflection Question Answers
A. If a surface is warm, the air above gets warmer. If a surface
is cold, the air above stays the same. Air takes on the
temperature of the surface beneath it.
B. The smoke hovered or sank over the cold surface
because cold air is heavy (dense)
C. The smoke rose over the warm surface because it is
lighter (less dense)
D. The hot rising air (which had evaporated the water) hit the
cooler tube and condensed (turned back to a liquid). Hot
air with water vapor rises and cools in the upper
atmosphere. There it condenses and forms clouds.
E. If earth’s surface is cold, the air above it will lose heat
energy to the cold surface below and remain close to the
surface. If earth’s surface is warm, the air above it will be
heated. Warm, moist air rises, changes to water vapor,
forms clouds at higher altitudes, and may fall to the earth
as precipitation.