Type of Lesson: Experiment
Time Needed: 45-60 minutes
MEGOSE PME2 Measure weight, dimensions, and temperature of appropriate objects and materials.
MEGOSE PME8 Measure physical properties of objects or substances (mass, weight, temperature,
dimensions, area, volume).
MEGOSE PME9 Describe when length, mass, weight, area, or volume are appropriate to describe the size of an object.
MEGOSE PWV4 Explain how light illuminates objects.
MEGOSE PWV5 Explain how shadows are made.
MEGOSE ES5 Describe and explain common observations of the day and night skies.
Quick Summary of Lesson
This lesson teaches about shadows and their relationships to time of day.
Students will measure the lengths of a meter stick's shadow at different times of the day (or seasons) to determine when a shadow casts its longest and shortest shadows.
Worksheet (at bottom of this page - please feel free to print and make copies!)
1. Have each student record the height of the meter stick. On their worksheet, the students should draw this in the column on the graph labeled meter stick's height.
2. Have students cast the shadows on blacktop or large sheets of paper and trace. Paper tracings could be brought indoors for display and comparison.
3. Measure and record length of shadow and time on the tracing.
4. Follow steps 2-3 at four or more time intervals during the day.
5. Compare the length of shadow cast at each time of day to the actual height of the meter stick. The students should also mark these times and heights on the graph on their worksheet.
6. Have students answer the disussion questions on their worksheets.
Student Activity Sheet
Please click here for student activity sheets. All activities on the Windows to the Universe site may be printed and reproduced if being used for educational purposes.
Notes to the Teacher
Two factors are involved here: the time of year, and the time of day the measurement is recorded. Shadows are long when the light source (sun) is low (morning and late afternoon) and shorter when the sun is high (noon). Shadows are longer in winter than in summer.
Students need to work in groups of three: one to hold the meter stick, one to measure, and one to record. Students may take turns at each job so that they have three sets of information. You must choose a sunny day so that shadows will be vivid and easy to measure and trace.
Select 4 times during the day that are convenient for your students to measure the shadows and that are well spaced during the day. Suggested times are 8:30, 10:30, 12:30, and 2:30. Or at the secondary level, measure with each of your class groups. Students need to position the meter stick on the same mark each time they measure the shadow. Use chalk to draw around shadows on blacktop or use butcher paper and black markers to make paper tracings.
You could extend this activity by selecting 4 times during the year, each in a different season, to repeat this procedure to gather data on how the shadow may change during the year.
Another possible extension of this activity includes having students trace the shadow of an object like a tall bottle onto a large piece of newsprint at hourly intervals during the day. Then lead a discussion of the movement of the shadows. You could also have students figure out the surface area of the shadows cast at various times during the day. Use centimeter grid paper.
Need More Information? Try Using Windows to the Universe
Please use these links for further ideas or more information:
Io's shadow on Jupiter
Lunar Lollipops - another classroom activity
Motion of the Earth about the Sun
An old headline piece about a lunar eclipse
Solar eclipses...the Moon's shadow
A tour on light
Venus capable of casting shadows
Last modified prior to September, 2000 by the Windows Team
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