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math_head7
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Homework Statement
A cord is attached to a cart that can slide along a frictionless horizontal rail aligned along an x axis. The left end of the cord is pulled over a pulley, or negligible mass and friction and at cord height h = 1.20m, so the cart slides from x1 = 3.00m to x2 = 1.00m. During the move, the tension in the cord is a constant 25.0N. what is the change in the kinetic energy of the cart during the move?
Homework Equations
W=Fxcos[tex]\Theta[/tex]d ?
[tex]\Delta[/tex]K= 1/2mv22F - 1/2mv2I ?
The Attempt at a Solution
I attempted to find theta by doing tan-1(1.2/2) getting angle 31.96 degrees. I then plugged that into Fxcos(31.96)d = 25Ncos(31.96)2.00m = 42.9J which was my answer. But the book says it's 41.7J. I just can't figure it out...