Essential University Physics: Volume 1 (4th Edition)

Published by Pearson
ISBN 10: 0-134-98855-8
ISBN 13: 978-0-13498-855-9

Chapter 5 - Section 5.3 - Circular Motion - Conceptual Example - Page 82: 5.1


The hair should be hanging upward.

Work Step by Step

The only forces acting on the hair are the gravitational force and the tension force. However, in order to remain in centripetal motion, the net force needs to be downward, meaning that the downward force must be at least as large as gravity. This means that tension must be downward. However, if the hair is going downward, the tension would be upward, so it is impossible for the hair to hang down as depicted in the cartoon.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.