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View Full Version : ATTN CU Boulder Students taking Statics and Structures

A41.8Turbo
09-11-2003, 09:33 PM
Have any of you guys tried problem 3.16 yet? Its freakin pissing me off, any help would be much appreciated!
CSMsi311
09-11-2003, 09:46 PM
post up the problem and i could do it. when is it due by?
A41.8Turbo
09-12-2003, 03:12 PM
Heres my best re-draw of the problem using paint.
No numbers(b,h not given) are involved, weights are equal, the origin is defined to be (0,0) at the first pulley. The pulleys are filled in with black, point A is just a ring.
A41.8Turbo
09-12-2003, 03:15 PM
The circles are frictionless pulleys, no angles were given in the problem, calling all engineers!
TheJackal
09-12-2003, 04:50 PM
it seems your forgetting some information...
CSMsi311
09-12-2003, 07:06 PM
what are the values for b and h. are all the weights equal to each other?

Is point A a pulley also? If so, are they saying there are 2 ropes attached to the middle weight.

Where is the origin defined?
A41.8Turbo
09-12-2003, 07:38 PM
Ok, hopefully picture is more clear, and some more info. I'm still stumped.
CSMsi311
09-12-2003, 09:48 PM
here is the answer i get.

A(.5*b - .866*h, .289*b - .5*h)

the angles between both lines are equal and I figured the angle to be 30 deg.

i could type out my work in Mathcad if that'll help.
CSMsi311
09-12-2003, 09:51 PM
I now know why all the CSM drop outs go to CU...


j/k
A41.8Turbo
09-13-2003, 02:40 AM
Hahah very funny. Thanks for your help, I didnt have time to really think about this problem becuase I have a thermo, physics and diff eq exam all on tuesday. Thanks again.

Could you attach the mathcad sheet so I can see the nuts and bolts to it, thanks again.
CSMsi311
09-13-2003, 12:47 PM
i typed this up quickly so there are a lot of red errors. just ignore them. The formulas are correct. I left some algebra at the end for you to double check. I was drinking some last night and i didn't feel like going over it again this morning.
CSMsi311
09-13-2003, 12:49 PM
ah yes.... x and y are the distances from the origin to A(x,y). Theta 1 is the left angle and Theta 2 is the right angle.
A41.8Turbo
09-13-2003, 02:21 PM
Thanks, yea I was drunk last night while replying to your post. Had to get messed up after all the studyin I've been doing.
djet820
09-13-2003, 02:56 PM
Originally posted by black civic
Thanks, yea I was drunk last night while replying to your post. Had to get messed up after all the studyin I've been doing.

Boulder will do that to ya.
Reno
09-16-2003, 01:07 AM
Who's teaching the class? I was in that class a year ago, there was a problem like that and another 3-stringed problem that I had trouble with that I remember.

Easy class overall though.