Recent content by Philip Wong

Homework Statement f(t) is a piecewise function: {0 0<= t< 1 {t*exp(2t) t = >1Homework Equations F(s)= L{f(t)}The Attempt at a Solution F(s)= L{t*exp(2t)} for this problem I just took the Laplace Transformer directly from the table which is: n!/ (s-a)^(n+1) and after plucking in the...

Well we were on double integrals, moving to triple integrals when the assignment was released. So it was rather straightforward to think the question was related to one or the other method to solve it.

Why yes I meant estimate instead of calculate. And I believe I know the difference between estimate and calculate in terms of English. Though I'm not too sure I correctly understand the difference in terms of calculus. I'll come back to this question once I had the material taught.

Ok, I'm kinda catching on. So z has two conditions, which is z =4 and z=0. In order to work out the limits of r, I need to rearrange my equation making r the subject. hence one would be z=0, therefore ##2r^2=8## which makes ##r=2## as its lower limits. the other one would be z=4, therefore...

what do you meant by think of dimensional analysis? I've read your post prior to my attempt, I think I did mention before my attempt that I do not understands what do you meant "what is ##r## in terms of ##z##" part. Can you please elaborate on that part more, and the part regarding on the...

yes you are right, I should have tried it first. I'm not too sure what do you meant by values of ##r## takes on depend on the value of ##z##. But this is what I think you meant, and my attempt to solve it. ##z= -2(x^2+y^2)+8## ##z= -2r^2+8## ∫^{2\pi}_{0}∫^{4}_{0}∫^{2}_{0}(##r...

well the assignment question used estimate. so can you tell me what's the difference between estimate and calculate in the context of this question? thanks, Phil

ok, I shall give that a try. but how should I do the ##dz## part? Do I first rearrange the equation to ##z+2(x^2+y^2)-8## and then integrate from there? Phil

ok, but even if I have the +8 in there, shouldn't still gives me a negative number? secondly should I keep using polar or should I really use triple integration? thanks

Homework Statement estimate the volume of the solid z=-2(x^2+y^2)+8 between the two plates z=4 and z=0Homework Equations In question like this, should I use triple integrals or double integrals in polar coordinates? I'm stuck in between which to use, because the question asks to estimate the...

the question is just say "An aluminium rod is to withstand an applied force of 200 kN". I guess its at orthogonal

Hi guys, I'm studying my first semester in engineering, I was giving the first assignment in my material science class which I'm not so sure on how to get started on. The assignment was to ask us to design a aluminum rod which has the following specification: 1) Withstand an applied force...

Adkins Jr: I see what you meant now. thanks for your help! voko: is the first one. sorry I'm not good using latex, I tried to have the equation type out using it. but somehow it didn't work

Homework Statement Find the velocity and acceleration of a particle with the given position function: r(t)=<2cos t, 3t, 2sin t/t+1> The Attempt at a Solution v(t)=r'(t) dt= <-2sin t, 3, (2cos t/t+1) - (2sin t/(t+1)2)> a(t)=v'(t) dt = <-2cos t, 0, (4sint t/(t+1)3-(2sint t/(t+1)-(4...

oh right. got it. thanks!