Science: 4-3.7 Interpret the change in the length of shadows during the day in relation to the position of the Sun in the sky.
Objects on Earth cast shadows that help show Earth’s rotation. The angle of the Sun, low in the sky to higher in the sky, changes the length of the shadow cast behind an object.
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Essential Question: How does the change in the length of shadows during the day relate to the position of the Sun in the sky?
How Shadows Change
As the position of the sun in the sky changes, shadows also change. A shadow is a dark area that forms when an object blocks light. A shadow forms on the side of an object that faces away from the sun. The length of shadows changes as Earth rotates.
In the morning, the sun is low in the eastern sky and shadows are long. As time passes in the morning, the sun seems to move higher in the sky. Shadows get shorter.
At midday, the sun appears highest in the sky. Shadows are shortest then or no shadow appears at all.
After midday, the sun seems to move lower and lower in the sky toward the west. As it gets lower in the sky, shadows get longer again. You can guess the time of day by observing the sun’s position and the length of shadows.
How Shadows Change
As the position of the sun in the sky changes, shadows also change. A shadow is a dark area that forms when an object blocks light. A shadow forms on the side of an object that faces away from the sun. The length of shadows changes as Earth rotates.
In the morning, the sun is low in the eastern sky and shadows are long. As time passes in the morning, the sun seems to move higher in the sky. Shadows get shorter.
At midday, the sun appears highest in the sky. Shadows are shortest then or no shadow appears at all.
After midday, the sun seems to move lower and lower in the sky toward the west. As it gets lower in the sky, shadows get longer again. You can guess the time of day by observing the sun’s position and the length of shadows.
Learning Tasks & Assessments: Students will view Science Facts and Fun: What’s in a Shadow? (Discovery Ed. Video Segment) and complete Video Viewing Guide. (DOK 2) Activity: Have students trace their shadow outside 3 different times in the day. (DOK 1) Notebook Entry: Have students illustrate the different shadows they traced (see activity above) in their notebook. (DOK 1) Journal Entry: How does the sun’s position affect the length of shadows during the day? Use evidence to support your claim. Concept Connection Activity: Changing Shadows Students will complete the activity sheet using data from their notebook entry. (DOK 2) Claims, Evidence and Reasoning: How does the sun’s position affect the length of shadows during the day? Concept Connection Activity: Changing Shadows Students will complete the activity sheet using data from their notebook entry. (DOK 2) Formative Assessment: Write Like a Scientist: Analyzing Student Work on Changing Shadows Activity Analyze sample student work and respond to the following question: Is your friend’s work correct or incorrect? Why? Cite evidence from the work and your notebook or any other resources you have. (DOK 3 Assessment Guidelines: The objective of this indicator is to interpret the change in the length of shadows during the day in relation to the position of the Sun in the sky; therefore, the primary focus of assessment should be to change one form of presentation, like a description or drawing, into another that shows this relationship. However, appropriate assessments should also require students to predict a time of day based on the amount of shade; or recognize/recall the reason that shadows change shape or the reason the Sun is in different positions in the sky. |
Resources:
Discovery Education Video Science Facts and Fun: What's in a Shadow? Learning How the Sun sets. Light and Light Energy: Exploring Shadows Shadows, Sun Rises, Sun Sets Virtual Lab Activity: When's the Shadow There? Interactive Site: Learn about how the Sun Creates Shadows on Earth Write Like a Scientist - Analyzing Student Work on Changing Shadows Activity |