Recent content by go_ducks

An expansion! I should've known...

Greetings, I'm a 4th year physics undergrad, hoping to avoid entering a 5th. Using 2nd edition of Callen for Thermo class in upper div. I'm having a real hard time solving any problem in this book. I haven't had nightmares over homeworks since my math methods class which used Arfken. The...

Well its equivalent until the last step, where you combined your BiDkAi and AidkBi together to form dk(BiAi) which looks like use of the product rule. At the end I didnt do that, I claimed "bj Di aj" = "del(A.B)" I think that is the issue. Because its not true... its one half of the...

Ok, tried BX(del X A) first of all a forethought, I expected result to look like the BAC-CAB rule, Ax(BxC) = B(A.C) - (C.A)B ...here, A->B, B->del, C->A, implying Bx(delxA) = del(B.A) - (A.B)del . Not that it makes sense to move the operator around like that... So anyway here's my results...

I will have to take a break because my head is hurting, but thank you, I had forgotten all about the x-hat. What a horrible mistake. I will see how this goes after my frontal lobe stops pulsating.

Sorry I left to go to Borders to look for a book. Came back empty handed. Anyway I tried that before. Let me know what I do wrong here then. B x (\nabla x A) let C = \nabla X A => [B x C]i = eijk BjCk now [\nabla X A]i = eimn \nabla m An => [B x (\nabla x A) ]i = eijkBj ekmn...

I have several problems like these, I am learning about Levi-Civita and Kroenecker delta so those may be relevant, however, what I am really looking for is further discussion or good books/online tutorials that are specific to usage of the del operator. Homework Statement I'm actually going...

I think you were referring to v = rw which I have used subsequently. Other than that, definitely still not getting it. It already seemed fairly self-evident that the radius of orbit should increase by the same amount that the hanging mass is raised by, but the professor said we weren't...

Yes after it moves. the question is find the new radius and new speed. I looked back over what I wrote here for method 3 and i put aw which isn't right but no worries, it still didnt go anywhere..

Homework Statement An air puck is rotating on a table top, attached to a hanging mass by a massless cord which passes through a hole in the centre of the table. Given variables are, radius R = 0.9 m. mass(puck) = 0.28 kg. mass(hanging mass) = 1.25 kg. Question is: a) tension in cord...

Would you guys mind condensing this for me? I'm just looking for a simple "start here" kinda answer to get going on math. Start with calculus.. is that what you are saying?

This looks almost identical a review problem in stewart.. 14.65 there's 3 different lengthed sides. the sides are P(2-sqrt(3)) P(3-sqrt(3))/6 P((2sqrt(3))-3)/3 I imagine you can just plug those in and solve for A. Now I must say that this is from a solution manual and I don't know how...

I'm not sure dude. My experience in calc 3 and linear algebra have been pretty bad. Differential equations was ok. I think it all snowballs though. Like if you are making frequent mistakes over negatives like that, and you are trying to understand a concept with a logic that's a bit elusive...

I'll agree, but the professors think they can just give you what you need and have you learn it on the fly. They say those courses are "helpful". There are some mathematically-inclined students that can do that, and do it damn well. I just sank . Heh. Think I'll start with reviewing calculus.

Yeah. I find myself in agreement with that. I'd say the math for Q.M. is a bit beyond my level having never taken linear algebra before until now. I mean a couple semesters from now I'm sure I'll get more used to it. That's what the professors promise anyway. Although to me, seems like just...