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Thinking About The Question

How can I describe and illustrate motion?

Some objects fall over when they are pushed or pulled while other objects move freely. Think about a tree blowing in the wind. The upper branches of the tree move with the wind. Once the wind stops, the tree sways back and forth until it comes to rest at its original position. This type of repeated motion occurs often in other situations. While you are playing with a yo-yo, the toy moves up and down and up and down. When a car is stuck in the snow or mud, the driver rocks the car forward and backward until it is freed. A tiger pacing in a zoo pen also shows repeated motion. Can you think of at least two more examples of repeated motion? Discuss this question with your team and write down some of your examples of repeated motion to share with the class.

Observe the following graph made by a motion sensor. Refer to Technical Hints to learn how a motion sensor works.

How can you tell from the graph that the motion is repeated?

How long does it take to repeat the motion? Write your answer below.

Think about the motion of a Slinky when you release one end and allow it to drop to the ground. The loose end of the Slinky drops and then suddenly bounces back. In fact, the Slinky will continue to move up and down in a repeated pattern for some time. Describe another object's motion that might produce a curved repeated pattern of motion.