Student Exploration: Conduction and Convection
Vocabulary: conduction, conductor, convection, insulator
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
Two pots have been sitting on the stove for a while. One pot has a copper handle and the other has a wooden handle. Which handle would you rather touch? Why?
One of the pots is filled with soup. The soup at the bottom of the pot is warmed by the stove burner, but how does the soup at the top get hot?
The Conduction and Convection Gizmo™ shows two flasks of colored water, one blue and one yellow. Select Copper and Solid chunk from the dropdown lists. (This means the two flasks are separated by a solid piece of copper, and the two liquids cannot touch each other.)
Use the sliders to make one flask hotter than the other. Click Play ( ). What happens?
Select the DATAtab and look at the graph. What do the blue curve and the yellow curve represent?
The blue curve represents
The yellow curve represents
What is the final temperature of the top flask? Bottom flask?
Get the Gizmo ready:
Click Reset ( ).
Question: Conduction is the transfer of heat from one object to another by direct contact. Which materials conduct heat most easily?
Observe: Run the Gizmo twice – once with a Solid chunk of Copper separating the liquids, and once with a Solid chunk of Stone. Watch how quickly the temperatures of the liquids change in both cases. (Note: This solid chunk keeps the liquids from mixing.)
Form hypothesis: A conductor allows heat to flow easily, while an insulator resists heat flow. In general, what kinds of materials do you think are good conductors?
Predict: Of the six substances in the Gizmo, which ones will allow the fastest temperature change in the two flasks?
Experiment: Experiment with all six Solid chunks. For each, click Fast forward ( ) and then, after about 500 seconds, Pause ( ). Record the temperature of each flask.
Analyze: What substances conducted heat the best?
How do you know?
Draw conclusions: What do the best conductors have in common?
Get the Gizmo ready:
Select Glass and Hollow pipe in the dropdowns.
Question: Convection is the transfer of heat by the movement of matter. In what situations does convection work best?