Articles liés à How Do You Lift a Lion?

How Do You Lift a Lion? - Couverture souple

Livre 3 sur 13: Wells of Knowledge Science

Wells, Robert E.

 
9780807534212: How Do You Lift a Lion?

Synopsis

How do you lift a lion? With a machine that's big and powerful with clanking metal parts? There are machines like that. But others have only a few moving parts. In fact, some machines are so simple that they don't seem like machines at all—like the wheel, the lever, and the pulley. These machines can make work easy—even if you're trying to lift a lion!

Les informations fournies dans la section « Synopsis » peuvent faire référence à une autre édition de ce titre.

À propos de l'auteur

Robert E. Wells is the author and illustrator of many award-winning science books for children, including Can You Count to a Googol? and Why Do Elephants Need the Sun?. He lives with his wife in Washington.

Extrait. © Reproduit sur autorisation. Tous droits réservés.

How Do You Lift a Lion?

By Robert E. Wells

ALBERT WHITMAN & Company

Copyright © 1996 Robert E. Wells
All rights reserved.
ISBN: 978-0-8075-3421-2

CHAPTER 1

DID YOU EVER TRY TO LIFT A LION?

You'd have to be awfully strong.

It's because of the force of GRAVITY. Gravity pulls objects downward. When that object is as massive as a lion, it pulls pretty hard.

With a LEVER, you can lift a heavy weight with much less effort.

The main part of a lever is a bar or rod which balances, or pivots, on a FULCRUM.

If the FORCE side is longer than the LOAD side, you will have LEVERAGE. Leverage adds force to your own strength. With a force side this long, you could lift a lion!

So, if you had a lever with a handle THIS long, maybe you could lift them a little!

Gravity is pulling down on that panda. And there's also FRICTION between the ground and the pallet. Friction, or resistance, happens when two surfaces rub together. The more weight pushing on the surfaces, the more friction there is.


(Continues...)
Excerpted from How Do You Lift a Lion? by Robert E. Wells. Copyright © 1996 Robert E. Wells. Excerpted by permission of ALBERT WHITMAN & Company.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

Les informations fournies dans la section « A propos du livre » peuvent faire référence à une autre édition de ce titre.