Conduction and Convection Gizmo Answer Key

Name: Jayleen Velazquez Date: 10-04-2022 Conduction and Convection Directions: Follow the instructions to go through the simulation. Respond to the questions andprompts in the orange boxes. Vocabulary: conduction, conductor, convection, insulator Prior Knowledge Questions (Do these BEFORE using the Gizmo .) 1. 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? It with the wooden handle. 2. 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? Heat does not travel through wood very readily. Gizmo Warm-up 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 ofcopper, and the two liquids cannot touch each other.) 1. Use the sliders to make one flask hotter than the other. Click Play ( ). What happens? The temperature makes an effort to level out. 2. Select the DATA tab and look at the graph. What do the blue curve and the yellow curve represent? A. The blue curve represents alters the blue flask's temperature. B. The yellow curve represents alters the yellow flask's temperature. 3. What is the final temperature of the top flask? 52.5 Bottom flask? 47.5 Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

Activity A:Conduction Get the Gizmo ready: ● Click Reset ( ). ● Set the Initial temperature of the top flask to 95 °C and the bottom flask to 5 °C. Question: Conduction is the transfer of heat from one object to another by direct contact. Whichmaterials conduct heat most easily? 1. 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.) 2. 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? Metal is a superb conductor, in my opinion. 3. Predict: Of the six substances in the Gizmo, which ones will allow the fastest temperature change in the two flasks? Copper 4. 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. Connection Initial temp. (top flask) Initial temp. (bottom flask) 500 sec. temp. (top flask) 500 sec. temp. (bottom flask) Solid copper 95 °C 5 °C 50.3 C 49.7 C Solid gold 95 °C 5 °C 51.1 C 48.9 C Solid lead 95 °C 5 °C 79.1 C 20.9 C Solid stone 95 °C 5 °C 93.6 C 6.4 C Solid glass 95 °C 5 °C 94.5 C 5.5 C Solid rubber 95 °C 5 °C 95 C 5 C 5. Analyze: What substances conducted heat the best? Copper How do you know? The temperatures equalize more quickly. 6. Draw conclusions: What do the best conductors have in common? They are all metals Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

Activity B: Convection Get the Gizmo ready: ● Click Reset . ● Select Glass and Hollow pipe in the dropdowns. Question: Convection is the transfer of heat by the movement of matter. In what situations doesconvection work best? 1. Observe: The Hollow pipe allows the water in each flask to move around and mix. Try several experiments with different temperatures in the top and bottom flasks. A. Describe what you see: The flask's hue blended with one another. B. How does the color show when convection (movement of hot water) is taking place? The mixture turns green. 2. Form hypothesis: Why do you think the water mixes quickly in some cases, while other times the water mixes slowly? Because one water is trying to move up and the other is trying to go down, the hotter water is onthe bottom and the colder water is on top. 3. Experiment: Predict the results of each experiment by writing “fast” or “slow” in the predictions column. Test your predictions on the Gizmo, and record the actual results . Initial temperature (top flask) Initial temperature (bottom flask) Mixing speed (predictions) Mixing speed (actual results) 95 °C 5 °C slow slow 5 °C 95 °C fast fast 4. Analyze: How do the positions of the hot and cold water affect the speed of convection? Due to the fact that heat seeks to rise and cold seeks to fall, the process is sped up by the hotwater being at the bottom. 5. Draw conclusions: Does hot water tend to rise or sink? Explain. Since it is less dense than cold particles, it rises. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

Activity C: Conduction vs.convection Get the Gizmo ready: ● Set the Initial temperatures of the top flask to 30 °C and the bottom flask to 70 °C. ● Select Gold from the dropdown list. Question: Which works more quickly, conduction or convection? 1. Observe: Experiment with a Hollow pipe of Gold and a Solid chunk of Gold separating the flasks. Compare how quickly heat is exchanged. 2. Form hypothesis: Heat can be transferred by conduction or convection. A. Which process do you think is quicker? Convection B. Why do you think this is so? The direct contacts 3. Experiment: For each of the situations below, record the temperatures after 100 seconds. Connection Initial temp. (top flask) Initial temp. (bottom flask) 100 sec. temp. (top flask) 100 sec. temp. (bottom flask) Solid gold 30 °C 70 °C 40.3 59.7 Hollow gold 30 °C 70 °C 50 50 Solid gold 70 °C 30 °C 59.7 40.3 Hollow gold 70 °C 30 °C 62.2 37.8 4. Draw conclusions: Does convection always work more quickly than conduction? Explain why or why not. Both fast and slow convection are possible. 5. Extend your thinking: You may have noticed that there was a big difference in the results of the two hollow pipe experiments, but very little difference in the solid chunk experiments. Why do you think this was the case? Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

For conduction, placement is not important, but for convection, it is. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved