Document Type

Article

Publication Date

3-2009

Publication Title

The Physics Teacher

Abstract

Consider a problem of sliding blocks, one stacked atop the other, resting on a friction-less table. If the bottom block is pulled horizontally, nature makes a choice: if the applied force is small, static friction between the blocks accelerates the blocks together, but with a large force the blocks slide apart. In that case, kinetic friction still forces the upper block forward but with less acceleration than the lower block. The choice, then, lies in the relative terms—what is meant by small and large? After a confusing experience during a recent exam, we’ve found a demonstration and graphical presentation that can help clarify the distinction between static and kinetic friction.

Volume

47

First Page

158

Last Page

161

DOI

10.1119/1.3081298

ISSN

0031-921X

Rights Statement

From Physics Teacher at Sherpa/RoMEO: Publishers version/PDF may be used on author's personal website, arXiv, institutional website, institutional repository, funders designated repository or private forums on social academic network after 12 months embargo.

© 2009 The Physics Teacher

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