problem06_77

# University Physics with Modern Physics with Mastering Physics (11th Edition)

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6.77: Denote the initial compression of the spring by x and the distance from the initial position by L . Then, the work done by the spring is 2 2 1 kx and the work done by friction is ) ( k L x mg + - μ ; this form takes into account the fact that while the spring is compressed, the frictional force is still present (see Problem 6.76). The initial and final kinetic
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Unformatted text preview: energies are both zero, so the net work done is zero, and 2 1 k 2 ( ) kx mg x L = + . Solving for L , , m 813 . ) m 250 . ( ) s / m 80 . 9 )( kg 50 . 2 )( 30 . ( ) m 250 . )( m / N 250 )( 2 / 1 ( ) 2 / 1 ( 2 2 k 2 =-=-= x mg kx L or 0.81 m to two figures. Thus the book moves m 06 . 1 m 25 . m 81 . = + , or about 1.1 m....
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## This document was uploaded on 02/04/2008.

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