Name: Sheri D.
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
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
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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Update: June 2012