Recent content by xophergrunge

Begin by looking at the equations for force due to a magnetic field and force due to gravity.

So that what is in equilibrium? I believe you are missing part of the question.

I believe that is a mistake in the text. I think he meant it to be the vector r and not r hat, in which case the denominator would be cubed.

Okay. So, what would happen if the centripetal force became greater than the weight?

Do you mean maximum? The minimum speed would be zero.

This should be D = ε0εrE Where are those 2's coming from?

What forces are acting on the motorcycle? In what directions are these forces acting?

Draw a free body diagram. How many tension forces T are there? What direction are these tensions in? Is it possible for them to "cancel" each other out?

Z≠2.5Ω.

I get I = 0.707 A.

You don't want to use V=IR, that doesn't take into account the reactance of your inductor. For a simple LR circuit V=IZ.

Do not set the first two equations equal to each other, they are not equal. The two forces acting on the mass, the weight and spring force, add to give the total force which will be zero when x=d.

The moment is a cross product, you haven't taken into account the angle between the moment arm and the force.

It seems like you are taking the correct steps. However, I get a different numerical answer than you do. Also, may I suggest that you don't plug all of those numbers in immediately, and just work with symbols until you have an expression for what it is you are looking for? It'll make the...

A variable to the first power's derivative is equal to one only when differentiating with respect to that variable. So, dh/dh=1, but dh/dt doesn't necessarily. You don't have to, but you would need to find dh/dt in terms of r and dr/dt and substitute that at some point. Personally I think it...