Recent content by elijah78

A big big big thank you to you guys for your help. i ended up with an A on the project and a B for the semester. Thank you!

A big big big thank you to you guys for your help. i ended up with an A on the project and a B for the semester. Thank you!

after all was said and done, I've figured out that it would take 2780N to get the vehicle up to 27.8m/s.

the only option i can see would be to pull 1 s out of the first 2 terms of each polynomial. if the K weren't there i could factor the polynomial using quadratic.

@everybody yeah the whole problem is about a vehicle moving from 0 =< t =< 100

chester that too is what i got, only i had plugged in some ICs along the way, making it harder for me to investigate different values of drag and what influence they have on other parameters. this makes it a little easier.

if it wasn't for that darn K. so: (y(0)/s)[ (KVo/My(0)) + s2 + (D/M)s ] / [ s2 + (D/M)s + (K/M) ]

this place is so cool. great, intelligent people. I'm glad i came here.

@rude man: can you explain that a little further? i know what separation of variables is but I'm having a hard time seeing it here. edit: i contacted my professor and he said Laplace was acceptable. thank god, i wouldn't have figured conventional int out!

ok so this time i got: Y(s) = [ (KVo/Ms) + y'(0) + sy(0) + (D/M)y(0) ] / [ s2 + (D/M)s + (K/M) ]

Laplace Transform expressions for y'', y', and vd(t).y''(t): s2Y(s) - sy(0) - y'(0) + (D/M)y'(t): (D/M)(sY(s) - y(0)) + (K/M)y(t): (K/M)Y(s) = (K/M)vd(t): (K/M)(Vo/s)then I factor out Y(s) and then solve for Y(s). that's when i get that ugly fraction up there that i don't know what to...

plugging in the variables into Y(s) i get: Y(s) = [ 27.8K + 20800s2 + 2080s ] / [ s2 + .1s + .001K ]

Homework Statement Solve the DE for y(t) with the IC's y(0)=20.8m/s and y'(0)=0 if the input is a step function scaled by the desired velocity Vo. vd(t)=Vou(t). Assume the desired velocity Vo=27.8m/s Homework Equations y''(t) + (D/M)y'(t) + (K/M)y(t) = (K/M)vd(t) M = 1,000kg D = 100kg/s K...

Alright thanks so much guys, it's 5am so I'm going to go sleep on it. Laplace, laplace, laplace... As soon as I get over this speed bump the rest is a breeze, MATLAB plots, etc. Thanks again!

yes Fourier and laplace. he told us to use the time domain. the block diagram is in laplace format i.e. S instead of jw. I've also tried: (1/m) / (s + D/m) D/m = .1 .001 / (s + .1) 1 / (s + .1) ---> e^(-.1t)u(t) i'm not sure if I'm doing the right thing with the m in the numerator's...