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Unformatted text preview: sign!) The x component is negative. The cosine of the angle between the string and the horizontal is cos = x/ (x 2 + h 2 ) Therefore, when the block is at x, the x-component of the tension is T x = -Tcos = -Tx/ (x 2 + h 2 ) At x = 3 m, the T x is T x = -Tcos = -303/ (3 2 + 2 2 ) = -25.0 N b) What is the change in the kinetic energy of the cart during the move? According to the work-energy theorem, the change in the kinetic energy of an object is equal to the work done on the object. The definition of work yields K = W = T x dx = [-Tx/ (x 2 + h 2 )]dx Changing the variable from x to s = (x 2 + h 2 ) and integrating from x 1 to x 2 , we get K = - Tds = -T[ (x 2 2 + h 2 ) - (x 1 2 + h 2 )] = 72.7 J...
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This note was uploaded on 01/25/2011 for the course PHY 2048 taught by Professor Field during the Summer '08 term at University of Florida.
- Summer '08