Heat Transfer and the Movement of Air

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Heat Transfer and the Movement of Air

Inquiry 4.2Big 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)

Hot water

Cold Water (ice)

Punk Stick

Tubing

Funnel

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 notes- How 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 Questions1. 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 becauseCold air is more dense so it sinks whereas warm airIs 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 AnswersA. 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.