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  if u can answer this i will be entirely grateful 
 
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tom riddle Jan 07, 2005, 12:45am EST Report Abuse
There was a steel beam 50 feet long. The entire construction crew (total weight: 6000 pounds) was standing at the center of the beam. Assume the modulus of elasticity is 29,000,000 pounds per square inch, the moment of inertia is 850 inches^4, the beam has simple pin connections at either end, and all loads other than the weight of the crew are disregarded.

How much will the beam deflect? Please round to the nearest tenth of an inch.


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Jan 07, 2005, 12:49am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
I would totally help you, but alas, I flunked PH212... :(

Diablos Jan 07, 2005, 12:59am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
Well that really depends on which processor the beam has, intel or amd. :P

Seriously though, it is just a matter of knowing the equation which incorporates those variables, and I'm sure you'll find said equation if you asked at the correct website.

By the way, I'm sure that your need to figure out this puzzle of all puzzles is dire but there really isn't a need to make 3 friggin' posts with the same stuff copy/pasted.

http://www.hardwareanalysis.com/content/topic/37246/
http://www.hardwareanalysis.com/content/topic/36053/

Mr. Aveng Jan 07, 2005, 02:36am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
I porbably could give you the answer if I bothered to sit down and work it out, but Im gonna let u do ur homework on ur own.

_________________________________
Triskaidekaphobia - Fear of Triscuits
Michael A. Jan 07, 2005, 05:23am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
Come on now...do your own homework. :)

Michael A.
Website: http://itnode.net
David Jan 07, 2005, 05:46am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
I *should* be able to tell you but i cant, ive actually got a structural mechanics exam in 2 weeks and i dont know squat (i should have turned up to some lectures) . Convert it to m/cm & n/kN and il give it a go as part of my revision

David.

_________________

Have a Nice Day :)
adam wilson Jan 07, 2005, 05:49am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
http://web.umr.edu/~insall/Student_Corner/Undergraduate%20Stud...amsrev.doc

have a look at that and see if it solves your problem

adam

tom riddle Jan 07, 2005, 06:48am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
so no1 is going to help me u helped the other person with a really hard question i saw so please i am very lost and do not understand it

t@kis ! Jan 07, 2005, 07:13am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
i hope your studying to be an designer and not an engineer.
heres a real good explanation.

http://darkwing.uoregon.edu/~struct/courseware/461/461_lecture...ure40.html

your beam loading is represented by the 2nd diagram down, left column.

equation is:

Delta (max) = (P x L squared) / 48 x E x I

where

Delta (max) = maximum deflection of beam in inches
P = Concentrated load on beam
L = beam length in inches
E = modulus of elasticity
I = moment of Inertia for beam shape used

its a very simple equation. have fun.


t@kis
2.6 p4 HT; gigabyte 8KNXP; 1GB corsair PC3200;Seagate Barracuda sata 120gb; ATI 9800pro AIW; Audigy 2ex; Antec true blue 350; lots of bling
tom riddle Jan 07, 2005, 07:27am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
any1 here who can walk me by step by step

Chris McGee Jan 07, 2005, 07:37am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
Try this:

Y = WL^3 / 48EI

where:

Y is the max deflection
W is the load
L is the length
E is the elastic modulus
I is the moment of inertia

I can't give you the numerical answer because we work in metric over here and I can't be arsed to convert it all. Hope it helps.

(It wasn't altogether clear in your question but I assumed it is a simply supported beam, for a fixed beam replace the 48 with 192)

edit: D'oh, just noticed I got beaten to the punch, never mind, serves me right for taking so long :-)

edit 2: t@kis, isn't it W x L cubed, rather than squared?

t@kis ! Jan 07, 2005, 09:46am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
i didnt crack open my old textbooks; just copied the formula from the page link i posted. that shows L squared.

but i do know that P is used for a concentrated load, like he had; W is used for an evenly distributed load. i say BFD!!

ive already endured the pains of structure class. i dont want to go thru it again. thats what structural engineering consultants are for!

EDIT 1: at the bottom of the page link i posted, their is another link to an example problem. The solution does use L cubed, not squared! WTF!! look at the formula on the main link- am i nuts or does that say L squared??

t@kis
2.6 p4 HT; gigabyte 8KNXP; 1GB corsair PC3200;Seagate Barracuda sata 120gb; ATI 9800pro AIW; Audigy 2ex; Antec true blue 350; lots of bling
Chris McGee Jan 07, 2005, 10:50am EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
yeah, it does say squared, kinda weird.

p.s. as a physicist, I don't use P or W for load, I just stick with m. Damn engineers complicating everything :-).

Chris McGee Jan 07, 2005, 10:02pm EST Report Abuse
>> Re: if u can answer this i will be entirely grateful
Just curious, tom, did you get it, what answer did you get?



 

    
 
 

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