Hey, I am actually a third year physics student, but here in New Zealand they tend to rush past the fundamentals, hence I can't seem to rearrange the following equations properly. Eq 1 and Eq 2 are:(adsbygoogle = window.adsbygoogle || []).push({});

τ=-erB*dr/dt ek

and

τ=m*d(r^2dθ/dt)/dt ek

Where ek is a unit vector. Is supposed to be rearranged to the form:

vθ(r) = (-eB/mr) * integral between r and a of r dr = (-eB/mr)*(r^2-a^2)/2

I can get very close but my derivative rearranging is sub-optimum. A little help would be really appreciated, as would telling me how the hell I write equations on the forum. Cheers.

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# Manipulating derivatives and rearranging

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