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/diy/ - Do It Yourself

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File: 91 KB, 1405x707, Screenshot 2024-06-08 132317.png [View same] [iqdb] [saucenao] [google]
2810816 No.2810816 [Reply] [Original]

how many /diy/ers can solve this question? the answer might surprise you!

>> No.2810818
File: 131 KB, 968x558, Screenshot 2024-06-10 at 10.10.28 am.png [View same] [iqdb] [saucenao] [google]

This is where the axis breaks.

>> No.2810836
File: 226 KB, 970x600, f3d567ab-efc7-4a4a-bcc1-4e7640e6143c.__CR0,0,970,600_PT0_SX970_V1___.jpg [View same] [iqdb] [saucenao] [google]

D) Neither, because the post and arm are made of steel tube painted to look like wood, and the black sphere and chain is made of polyethylene and from picrel

>> No.2810864

yeah but the beams are covered in burning jet fuel

>> No.2810885


>> No.2810894

They say that wood performs better in compression than in tension, and I believe that's true. If we assume that the joint between beam and post is unbreakable, and that the wooden beam is uniform and unbreakable *except* for those two points, then the point that's in tension (A) will break first. "First", but just barely. The failure of A will almost immediately lead to the failure of B.

But I'm a B-fag when it really comes down to it.
>muh hula hoops

>> No.2810903

lol at people overthinking this. it's a.

>> No.2810931
File: 20 KB, 602x360, main-qimg-c93a5371ab853afa4ab13df826b48cea-pjlq.jpg [View same] [iqdb] [saucenao] [google]

c) it snaps like spaghetti into 3 pieces

>> No.2810948

at the knot

>> No.2810965
File: 154 KB, 2758x1679, trap.png [View same] [iqdb] [saucenao] [google]

>be me
>get engineering degree
>apply at company
>give me mechanical aptitude test
>hear nothing
>put on my super charm and call secretary to pump for info
>"so have you heard anything?"
>"well you scored higher on the mechanical aptitude test than anyone who has ever taken it so I can't imagine they wouldn't want you."
>feels good man
>they never called

knowing is the true failure. also the answer is D. it won't break if it's not already broken in this scenario. nothing is changing so it is a static system shown.

>> No.2810979

>well you scored higher on the mechanical aptitude test than anyone who has ever taken it so I can't imagine they wouldn't want you
that was sarcasm, anon. they were probably laughing together about your test result when you called.

>> No.2810980

But that won't melt it

>> No.2810997


>> No.2811946

>do my homework for me!
The real life answer is this >>2810948, but assuming the material is homogenous then it is most likely to break at A. Since the top of the material is in tension while the bottom is in compression.

>> No.2811985

>They say that wood performs better in compression than in tension
the tensile strength of a wood beam along the axis of the fibres is much higher in tension than in compression
however compression doesn't lead to cracks

>> No.2812053

I mean it took like 70 years to figure out why the baseball bat breaks backwards so maybe don't get too wrapped up in the details before we even know what type of wood we're talking about.

>> No.2812212

wood is anisotropic but like other anons have said it usually performs better in tension, so B
there are also shear forces in the axial and normal direction but i don't think that matters much here

>> No.2812214

did you know that trees naturally grow compressionwood and tensionwood, old woodcrafters used to exploit these properties to get the most out of their timber, a detail lost on modern carpentry

>> No.2812215

in fact they now actively avoid sawn timber with reactionwood because it doesn't comply easily

>> No.2812230

was used in bowmaking as well

>> No.2813784

>D) Neither
That would be answer C.

>> No.2813937
File: 7 KB, 225x225, spoon.jpg [View same] [iqdb] [saucenao] [google]

>mechanical aptitude test
They don't have hard questions like "is a bicycle's right pedal left threaded?" Instead they're testing if you remember getting splashed while washing cutlery.

>> No.2813943

But it might make it deform instead of cracking

>> No.2816096

Yeah, but that doesn't explain why the one next to it cracked too.

>> No.2816232
File: 375 KB, 1604x776, 1719128797368.jpg [View same] [iqdb] [saucenao] [google]

There's nothing to discuss. Typical construction timber has properties of C24. It's in german but tension strength of 14 N/mm2 is a lot lower then compression strength of 21 N/mm2.

The part of cross section in your example is the top part, the solution is A. Here is video of a four point bending test https://youtu.be/ws7eJPYda2s

>> No.2816557

You was white, cracka.

>> No.2816573

>Here is video of a four point bending test
literally the opposite situation op asked for

>> No.2816591

No it's not, it's bending in both cases.

>> No.2816596

doesnt have to melt to be structurally useless

>> No.2816872

>black sphere

close, but that's jigglypuff viewed from above (painted black)