Heat Absorption Gizmo Answer Key

Name: Thomas Horn Date: 12-09-2022 Heat Absorption Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: absorb, greenhouse, radiation, reflect, thermal energy Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Is it usually hotter outside when the Sun is low in the sky, such as early in the morning, or when the Sun is high in the sky, around noon? Normally, the area around the moon is significantly hotter. 2. If you want to stay cool on a hot, sunny day, should you wear black or white? Why? White because materials that are white distort light more than those that are black. Gizmo Warm-up In the Heat Absorption Gizmo, a powerful flashlight can shine on a variety of materials. Make sure that the Light color is set to White. 1. Drag the Wood under the beam of light. What do you notice? The wood reflects some of the light. 2. What is the color of the light that is reflected off the wooden block? Brown 3. Click Play ( ) to start the clock. A. What happens to the temperature of the wood? The temperature rises B. The light that is not reflected away is absorbed by the wood. What does the absorbed light energy do to the wood? The wood is heated by the light energy absorbed. Energy that is transmitted through space by light waves is called radiation. The wood gets hotter because it gains thermal energy from the light waves. Get the Gizmo ready: Activity A: Angle of light ● Click Reset ( ). ● Check that Light color is still set to White. ● If necessary, drag the Wood under the light. Question: How does the angle of light affect heating? 1. Observe: Drag the flashlight to several different angles. When is the light beam most concentrated on the piece of wood? The flashlights are squarely above the timber at a 90-degree angle. 2. Form hypothesis: How will the angle of light affect how much the piece of wood is heated? The wood will heat up more if more light is shone upon it because it will absorb more energy. 3. Predict: Which angle will result in the hottest piece of wood? 90 degrees 4. Experiment: For each angle listed below, record the final temperature of the wood after 3 hours of heating with the flashlight. Final temperature 20° angle 40° angle 60° angle 80° angle 90° angle 25.4 30.1 33.7 35.5 35.8 5. Draw conclusions: Why did increasing the angle of the beam of light cause the wood to heat up more? When the angle was low, the flashlight's light was dispersed over a wide area and missed much of the wood, but when it was near to 90 degrees, all of the light was focused on the wood. 6. Apply: St. Louis, Missouri, is located near the middle of the United States. On June 21, the noon Sun rays hit St. Louis at an angle of 75°. On December 21, the noon Sun rays hit at an angle of 28°. How will this affect the temperature in St. Louis on these dates? Due to the sun's angle being significantly lower on December 21 than it is on June 21, the energy from the sun will be more dispersed and less concentrated, making it cooler. Get the Gizmo ready: Activity B: Colored materials ● Click Reset. ● Drag the flashlight so that the Light angle is 75°. Question: How do colored materials absorb and reflect light? 1. Observe: Drag the red brick under the flashlight beam. Try three different Light colors: red, blue, and green. A. What color(s) reflect off a red brick? Red light is reflected from a red brick B. What colors of light are absorbed by the brick? Green and blue 2. Predict: Predict what color(s) of light will heat the red brick the most and the least. Most heating: blue Least heating: red 3. Collect data: Heat the red, green, and blue bricks under each color of light. Record results. Red light Blue light Green light Red brick final temperature 20.2 27.3 26.8 Green brick final temperature 25.3 27.3 20.3 Blue brick final temperature 25.3 20.3 26.8 4. Analyze: Based on your data, what light colors were absorbed and reflected by each brick? Red brick reflects red light, absorbs blue and green light. Green brick reflects green light, absorbs red and blue light. Blue brick reflects blue light, absorbs red and green light. 5. Extend your thinking: White light is a combination of red, green, and blue light. Why is it cooler to wear a white shirt on a sunny day than a black shirt? A black shirt will absorb all the colors present in white light, while a white shirt will reflect all the colors present in white light. Activity C: Comparing materials Get the Gizmo ready: ● Click Reset. ● Change the Light color to white. Question: Which materials are easiest to heat up? 1. Predict: In this activity you will compare how metal, wood, water, and brick heat up. A. Which substance do you think will heat up the most? metal B. Which substances will heat up the least? wood 2. Experiment: Using white light, heat up each of the following substances for 3 hours. Final temperature (no glass cover) Metal Wood Water Black brick White brick 22.3 50.2 36.0 56.5 27.6 3. Analyze: Based on the results, which substances do you think reflected the most light? The most light was reflected by the metal and the white brick. 4. Experiment: A greenhouse is a building with a glass roof and walls. Light can get in, but the heated air inside cannot escape. Click Add glass cover to simulate conditions in a greenhouse, and heat up each substance. Record your results below. Final temperature (under glass) Metal Wood Water Black brick White brick 23.5 50.2 36.0 56.5 27.6 5. Analyze: What effect did the glass cover have? Each material warms up more quickly 6. Extend your thinking: Why is it dangerous to leave an infant or pet in a car on a sunny day with the windows rolled up? because the automobile or your pet could die from the heat inside.