Work done by moving unit charge along straight line segment

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 2K views
tronter
Messages
183
Reaction score
1
If [tex]\bold{F}(x,y) = \frac{k(x \bold{i} + y \bold{j})}{x^{2}+y^{2}}[/tex] find the work done by [tex]\bold{F}[/tex] in moving a unit charge along a straight line segment from [tex](1,0)[/tex] to [tex](1,1)[/tex].

So [tex]\bold{F}(1,y) = \frac{k(\bold{i} + y \bold{j})}{1 + y^{2}}[/tex]. Then [tex]x = 1, \ y = y[/tex].

[tex]k \int_{0}^{1} \frac{y}{1+y^{2}} \ dy[/tex]

[tex]u = 1+y^{2}[/tex]

[tex]du = 2y \ dy[/tex]

[tex]\frac{k}{2} \int \frac{du}{u}[/tex]

[tex]= \frac{k}{2} \int_{0}^{1} \ln|1+y^{2}|[/tex]

[tex]= \frac{k\ln 2}{2}[/tex].

Is this correct?
 
Last edited:
Physics news on Phys.org