The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
According to Isaac Newton, an object at rest will remain at rest, and an object will remain in motion unless acted upon by an outside force. A force, therefore, is what causes any object to move. Any force that causes an object to rotate, turn, or twist is called a torque. Torque is equal to the amount of force being exerted on the object times the object's rotation point to the location where the force is being applied on the object.
Seesaws are a good example of torque. Many people have had the experience of a large person sitting on one end of the seesaw, and a small person on the other end. If the larger person is sitting closer to the pivot point of the seesaw, the smaller person can lift them with little or no problem. The reason this is possible comes from the difference in torque experienced by each person. Even though the smaller person exerts a smaller force, his distance from the pivot point (lever arm) is longer, hence a large torque. The larger person exerts a larger force; however, because he is closer to the pivot point, his lever arm is shorter, hence a smaller torque.
Wrenches also work by torque. (Some wrenches are even calibrated to display the amount of torque you are applying to a nut; they are called torque wrenches.) The nut (or bolt) is the point of rotation because we either want to tighten or loosen it by having it turn. The force is being exerted by your hand and arm. Since we try to pull or push (exert a force) at right angles on the wrench's handle, the lever arm is then the length of the wrench's handle. To increase the torque on the nut, we must either increase how hard we pull or push on the lever arm; or, increase the length of the lever arm by placing a pipe over the end of the wrench.