Drawing Ellipses Activity
Understanding the shape of planetary orbits
Materials:
Sidewalk chalk
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Nylon chord (one piece-ten feet long)
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Direction sheet
This activity will be done in groups of three students each as assigned by the teacher
Step one: Drawing a circle
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1 Tie the ends of your cord together
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2 Choose one person in your group to be the center
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3 Place the cord around the ankles of the person in the center
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4 Choose one person to draw the circle
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5 The person drawing the circle should secure the chalk inside of the cord
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6 Pulling the cord taught, draw a circle around the center person
Draw and explain your observations:
Step two: Drawing an ellipse
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1 Choose two people to be the foci of the ellipse and have them stand a few feet apart
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2 Place the same cord used for the circle around both of their ankles
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3 The third person secures the chalk in the cord and pulling it taught draws an ellipse around the two foci
Draw and explain your observations: