Mechanics of Materials: Lesson 3 - Normal Stress with Distributed Load

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[bArda]

I used to watch your videos years ago for statics. I did pretty well thanks to you, especially the M-V graphs with integration saved me because I hated cutting into billion pieces...Time flies and I work now! Thank you! I still sometimes watch your videos for fun lol

[Vyantri]

Jeff Hanson is like a legend on r/EngineeringStudents.

[J-Stew_]

You're the greatest engineering professor of our time - you've helped millions of students be sucessful in school in life, thanks for your hard work! Hanson > Khan Academy

[xxippixx]

These videos are genuinely the best. With online classes due to covid, I am struggling to engage with my own professor's video lectures. Your upbeat attitude and sense of humor with the viewer have me shouting out answers to your questions like you can hear me. You got me through statics a few years ago and I am very glad I coincidentally waited to take structural mechanics until after you recorded a class for it!

[davidnunez]

Jeff's student voice cracks me up!

[ashikrahman]

You understand exactly what we think while going along the lecture.

[darrennixon]

I think the question is for 1.25>x>.5, you wrote it the other way around. minor thing but I got confused :)

[christymatta]

why did he take the cross sectional area of a circle instead of the rectangle (isn't the beam rectangular?)

[zouraizkhan]

amazing video but i dont understand the need for the range you have provided and on top of that it looks wrong to me. x is smaller than 0.5m and is greater than 1.25m?

[AeroCraftAviation]

What if I were to come in from the left side, taking a section before the 6 kN force, and then a section between the 6 kN and X? Would that work too?

[invincibleparadox]

Sum of all the forces in the X axis is N=13000-8000x. And area of that beam is 7853.98. and these values are from the cut section of a beam which have length of "1.25-x". But in the end you are telling, with these values we can find normal stress of a cut section beam which has a length of 0.75m. ig you're wrong sir

Edit 1:
Maybe it's cuz normal stress from the point where 6kN acting to the end of the beam is same throughout the beam. Correct me if I understood right.

[Mr_Jonathan_Greer]

Going over these videos as a refresher. Thanks for posting. BTW, some of your links are no longer working in the description

[graysonnipper]

would this still work if you looked at the left hand side "slice" of the beam? I end up with a different function

[josephh.]

But why do we not make the section cut at 0.5? This is what the question is asking for, correct? Then we could do the FBD from there to the right of the cut.

[praketakshantala]

How would we write an equation for the normal stress from 0<x<0.5?

[jayfoolish]

why is the distributed load is +ve and not -ve, just can't understand the direction of Fx, why it going right instead of going left, pls I struggle with this a lot, always have hard time get the right direction

[khalidalsharari]

where the 50 came from? the number is 100mm!!! anyone explain please

[kyeler]

1newton/1millimeter is equivalent to 1n/1m^3
in other words, 10^3
so, a newton divided by a millimeter is not a megapascal, but a kilopascal.
Do the math for 13kn/7853.98m^-3 and you will see that it equals 1655 pascal or 1.65 kPa

[ashikrahman]

normal stress A=2pieR, sheer stress A=pierR^2. I'm confused.

[carlosgalvis]

Whats your most convenient Moment direction? clock wise or CCW?