Recent content by Jumblebee

Never mind! i just got it to work!

So I have really been struggling with this question. The original question said: The map \varphi:Z->Z defined by \varphi(n)=n+1 for n in Z is one to one and onto Z. For (Z, . ) onto (Z,*) (i am using . for usual multiplication) define * and show that * makes phi into an isomorphism. I know that...

help, I'm still stuck, can anyone help me?

I still can't get this one to work out. Am I still missing information? I tried starting with the equation mv'= -m'*vext+Fext. I solved for v'. and then substituted in the equation m0-kt. But then I didn't know where to go from there.

Okay, so I need to fix my velocity, but I don't really know what to do with it, the only thing i know about it is that it is moving up with a constant acceleration, but then what happens with the phi?

Do I not need to integrate then? I just don't know where the power of b/k comes from.

the question really says differentiate these expressions with respect to time to find dr/dt, dphi/dt, and dz/dt. i guess i just don't see how to differentiate these, because aren't I differentiating with respect to t, but there isn't a t in any of the polar terms.

Oops, i didn't catch that before thank you, another quick question, I am suppose to differentiate these expressions with respect to time to get dr/dt, dphi/dt and dz/dt. But i got confused on this part because i don't really understand partial differentiation, would i have like something with a...

I= 1/2 m R2? Just checking before I go on with the partial derivatives.

so if i remember right v=x' but i am not sure what I and w are in terms of x and derivatives. doesn't I have something to do with R, the radius?

Homework Statement Using the usual angle \phi, as generalized coordinate, write down the Lagrangian for a simple pendulum of length l suspended from the ceiling of an elevator that is accelerating upward with constant acceleration a. Find the Lagrangian equation of motion and sho that it is...

Homework Statement Consider a rocket subject to a linear resistive force, f= -bv but no other external forces. Using the equation mv'= -m'*vext+Fext show that if the rocket starts from rest and efects mass at a constant rate k= -m' then its speed is given by v=(k/b)vex[1-(m/m0)^b/k] The...