Recent content by SimbaTheLion

What is the 'free region of interest'? If I take a +J thing from one cylinder and then subtract the J bit from the other cylinder, surely I'm going to end up with an expression for the stuff in between the two cylinders? The question asks for the field within the smaller cylinder, not between...

Homework Statement Question 3 of http://www.damtp.cam.ac.uk/user/examples/B10b.pdf . Homework Equations \nabla \times B = \mu_0 J The Attempt at a Solution I know for a cylinder, J (vector) = J (scalar) * k (vector), where unit k is the vector in the z-direction. So \nabla \times...

Mmm, I'm getting an integral of something similar to 1/x² between -infinity and infinity, that doesn't look good...

Homework Statement "Compute the electric field due to an infinite line charge by integrating the expression obtained from the inverse square law." Homework Equations I think that the equation required is: E(\bold{r}) = \frac{1}{4 \pi \epsilon_0} \int_{-\infty}^{+\infty}...

Yeah, the hand is in the stream. Hmm, so is what I've done in the first post correct? If so, how do I continue?

Well, suppose the fluid had kinetic energy E = mU²/2. Then we need to find h such that mgh = mU²/2. So h = U²/2g. Is that all I have to do? :S

"If you put your arm in a stream flowing at U metres per second, how far can water rise up it?" Not really sure if what I'm doing is right. Presumably it depends on the angle of your arm in the water. If we let the speed of the water at your arm be V, we get, by Bernoulli, taking the height...

Homework Statement The Wikipedia part of question 5 here: http://www.dpmms.cam.ac.uk/site2002/Teaching/IB/MetricTopologicalSpaces/2007-2008/Examples1.pdf Homework Equations All relevant information is given in the question above. The Attempt at a Solution I'm trying to simplify the...