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norcal
Mar3-07, 01:27 PM
1. The problem statement, all variables and given/known data

What work is done by a force (in newtons) F = 3.1xi + 3.1j, with x in meters, that moves a particle from a position r1 = 2.1i + 2.5j to r2 = - -4.9i -3.9j?

2. Relevant equations

Work=integral(Fdx)

3. The attempt at a solution

W1=integral of Fxdx = integral (3.1x)dx
= 1.55x^2 evaluated at x2=-4.9 and x1=2.1.
= [(1.55(-4.9)^2)-(1.55(2.1)^2)]
= 30.38 J
W2=integral of Fydy = integral (3.1)dy
= 3.1[(-3.9)-(2.5)]
= -19.84 J
Wnet = W1+W2
Wnet = 30.38-19.84
Wnet = 11 J

But my answer, 11 J, is incorrect...

arildno
Mar4-07, 07:30 AM
This is totally incorrect, on several levels.

To give you a hint of how to solve this properly, answer the following question:
Is F a conservative force?