Conceptual Physics (12th Edition)

Published by Addison-Wesley
ISBN 10: 0321909100
ISBN 13: 978-0-32190-910-7

Chapter 5 - Think and Do: 21

Answer

This is a "hands-on" demonstration (see what we did there?). Try it and see! Make sure that you are not driving, and that your hand does not strike any object outside the car. When you tilt the front edge of your hand up a bit, it pushes and deflects air downward. Your hand is accelerated upward by the reaction force, the air pushing on your hand.
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