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assaftolko
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Homework Statement
Two positive charges of q=3*10^-6 C are a distance 1 m apart.
What will be the work done by the electrical force in bringing one of the charges to a distance of 0.5 m from the other charge (which is fixed at its position through the whole process)?
Homework Equations
The Attempt at a Solution
Well from W=-ΔU I got w=-0.081 J which makes since because the electric force acts in contrast to the path of q as it moves closer to the other q - and so negative work is done. But when I tried to calculate the work directly from W1->2 = ∫[itex]^{2}_{1}[/itex]Fel [itex]\bullet[/itex]dr when 1=1m and 2=0.5m , I got the same result but positive - since the angle between Fel and dr is 180 deg... why is that? Isn't dr pointing to the direction of heading?
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