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Name:  Sheri D.
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: 2000-2001

Can you give us a simple explanation, definition and examples of centripetal force for us that our elementary students will be able to understand? We are totally confused with the information that we have read already.


If you do not pull on something, it tries to travel in a straight line. To make it turn, you have to pull in the direction of the turn. If the object turns along a circular path, this sideways pull is toward the center of the circle.

When a car turns sharply, your body wants to continue in a straight line. You keep going straight, while the car turns in front of you. As a result, your body crashes into the door. This is why the door pushes hard against your body.

A good classroom demonstration of centripetal force requires a narrow glass or plastic tube, both ends open, with one of the ends very smooth. Hold the tube with the smooth end up. Run a string through the tube. Hang a weight on each end. The bottom weight provides the centripetal force while the top weight is spun around. The string pulls on the spinning weight, making it turn in a circle. The bottom weight indicates the amount of centripetal force. The demonstration/experiment is most convincing when the bottom weight is significantly greater than the top weight.

Dr. Ken Mellendorf
Illinois Central College

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