Trusses Method of Sections | Mechanics Statics | (Solved examples)

[@QuestionSolutions]

At 9:08, there is a typo. F_HI = 42.5 NOT 45.2.

[@remyfru]

I thought I was losing my mind when I solved it myself and watched it back, thanks for clarifying, and thanks for the great video.

[@QuestionSolutions]

@@remyfru You're very welcome :)

[@davidaum07]

@@QuestionSolutions thanks

[@yanskiejusain9611]

My professor's lecture video was 45 minutes long, but this 11-minute video was elaborated well. Thank you.

[@QuestionSolutions]

You're very welcome! I try to make them as concise as possible.

[@zach.frederick]

Wish my $2500 a semester could go to this guy instead of the professor that blabbers about how easy it was for them when they took the class 30 years ago. This guy is goated fr fr :0

[@NOTONtechsx]

@@zach.frederickMine is $3000 a semester and our professor just blabbers useless stuffs 🥲

[@katomiyamashita2870]

My prof sent a video lecture that's like 8 hrs

[@PunmasterSTP]

How'd the rest of your class go?

[@رياضالصالحين-ل5ب]

انا عربي اشكرك على جهودك هذه ولك التوفيق ان شاء الله في الدنيا والأخرة I am an Arab. I thank you for your efforts. May God grant you success in this world and the hereafter

[@QuestionSolutions]

You're very welcome! keep up the awesome work with your studies.

[@DirkdeZwijger]

Great video, clear explanation of how and why to use this method. Basically a time-saver for convenience sake is what I get from it. Understanding this method also boosts your insights and understanding of statics

[@QuestionSolutions]

Glad it was helpful! Keep up the great work and best wishes with your studies.

[@musabbirahmed4591]

thank you so much for existing. I promise you one day when I become a successful civil engineer I will contact you surely and thank you for every help u did throughout my engineering program. Just remember me. I am taking a screenshot of this comment.

[@QuestionSolutions]

You’re very welcome. I’m glad to hear that you’re pursuing your dream of becoming a civil engineer. I’m sure you’ll do great things in the future. I appreciate your kind words it means a lot to me. Best wishes :)

[@garrettsanford1493]

I should be paying you my college tuition How am I paying some boring dude to tell me about physics in the most unstructured way at 8am for $1800 when you just make it so simple and quick. Hats off

[@QuestionSolutions]

Thank you very much. I hope you do amazingly on your courses and I wish you the best! Keep up the great work :)

[@earnstein7607]

Thank you so much. You don't know how much you've helped me tonight ♥️

[@QuestionSolutions]

You're very welcome! I am really glad to hear this helped :) ♥️

[@xyz-hz9zc]

Thats what she said💀

[@petrus2746]

For anyone wondering why Force BG was eliminated 3:01, it's because it's vertical component goes through B and so does its horizontal component

[@QuestionSolutions]

That's right, but even more easier to remember is to keep in mind that any force starting where the moment is calculated, cannot create a moment at that point. The same as force BC.

[@kon8024]

Im happy you engage with the people in the comments. It seems all my answers have been answered! Thank you.

[@QuestionSolutions]

Thank you, I try my best to make sure I answer all the comments I get. :)

[@PunmasterSTP]

Method of sections? More like "Magnificent and knowledgeable explanations!"

[@QuestionSolutions]

Haha, thanks! :)

[@swaggyseth1454]

huge video, got a silly little quiz tomorrow, this will definitely help!

[@QuestionSolutions]

Glad to hear. Best wishes with your quiz tomorrow!

[@HaymanotShitie]

Thanks very much,qm from Ethiopian 🇪🇹 Keep it up

[@QuestionSolutions]

You're very welcome!

[@darthplague]

The example my professor gave only had 1 external force, so i didn't know that I had to calculate the moments of the other downward forces Thank you

[@QuestionSolutions]

You're very welcome. I try to pick at least 3 examples to remove any confusions in students. :)

[@muhammadsaadkhan9701]

Oh My God . This Lockdown means free time and your channel means free great quality explanation . Thank u so much 🌹. Enjoying Mechanics . ❤️🥰

[@QuestionSolutions]

Glad to hear you enjoy mechanics. ❤️ You're very welcome and I hope you learn lots!

[@OptimusXZero]

Really helpful. The visual is really helpful for my learning!

[@QuestionSolutions]

I am really glad to hear that!

[@smartybayan6646]

For the 3rd problem. The Force HI is 42.5. Thank me later.

[@QuestionSolutions]

👍

[@iyakintv5144]

yeah.. this should be pinned. It can also be obtained by applying summation of moment at A.

[@makristaamada-yo2uy]

thanks i thought i got it wrong

[@ElCrankoPunko]

@9:12 Force in HI member would be 42.5 kN

[@QuestionSolutions]

Yup, there is a typo. Thank you for pointing it out.

[@joeyni2861]

Thanks question solution for this video it really helped me with my quiz tomorrow just a quick question wouldn’t it be easier to take the moment at B first then take the sum of Fy to get Bg isn’t that easier?

[@QuestionSolutions]

You're very welcome. Could you please give me a timestamp so I know where you're referring to, then I can take a look. Thanks!

[@tebarekyosef8623]

you ae the best problem solver 10Q

[@QuestionSolutions]

You're welcome.

[@OGTennyson]

Has anyone ever told u ur a life saver?🥺🥺

[@QuestionSolutions]

I think I heard it about 3 times now, from very kind people like you leaving nice comments. Thank you, it made my day! Best wishes with your studies.

[@OGTennyson]

@@QuestionSolutions thank you!... and ur very welcome ❤️

[@QuestionSolutions]

@@OGTennyson ❤

[@OGTennyson]

@@QuestionSolutions I watched like 10 of ur videos already and it's so damn informative. U got a new subscriber my friend...keep up the good work on the videos bro ✅❤️...I rlly hope one day I'll make it as a civil engineer and be able to donate cash to ur channel because I feel ur teachings are highly underrated and I wouldn't want you to stop 😭. Keep the videos coming bro...imma be here 4 a while❤️

[@QuestionSolutions]

@@OGTennyson Thank you very much! Don't worry, you will make it as a civil engineer, you'll do great. Keep up the great work, do as many questions as you can, and use every resource out there to help you succeed. Especially those office hours from professors. 👍

[@Lostwolf16]

Thank you so much, while cutting section, can I make a slanted (diagonal) cut to avoid solving for member that I really don't need for problem?

[@QuestionSolutions]

Yes, you can cut vertically, horizontally, diagonally, etc. 👍

[@Lostwolf16]

@@QuestionSolutions Thank you

[@israfeelaheadmhadi102]

It is the best channel I have seen. Greetings from Iraq 🥀♥️🎉

[@QuestionSolutions]

Thank you very much! :)

[@favouragu285]

Thank you so much But there was a litt'l mistake in the 3rd problem; you use sine for the X components and cosine for the Y components

[@QuestionSolutions]

You are incorrect in thinking that sine is for x or sine is for y components or cos is for x components or y components. It doesn't work that way, and you are not alone, countless students make the same mistake on exams, and points get taken off. Please watch this video, it's less than 60 seconds and it will help you not make the same mistake I see so many students making. kzbin.infovynnKlJD_Jo?feature=share

[@egsbue]

thank you so much for this, just the right time i found your channel before our quiz tomorrow!

[@QuestionSolutions]

Glad I could help! I wish you the best on your quiz tomorrow :)

[@PasantAssem]

inspiring solution for real

[@QuestionSolutions]

Thanks!

[@Alicia-de4hj]

This was so helpful! Thank you for your easy explanations

[@QuestionSolutions]

You're very welcome. Glad to hear it was helpful

[@abidemiahmed9309]

I'm glad I'm watching this video, I'm having my mechanics exam next week. But I feel you're a lil bit fast in explaining, seems quite difficult to catch up mentally. Like, before I process a part, you'd have gone 3 parts. Also, can you help write the equation one by one. You have real good content, but just to avoid confusion.

[@QuestionSolutions]

I try to keep these videos concise, so it doesn't take up too much time. It can be difficult, especially when being introduced to the subject for the first time. So I will keep what you said in mind, but try to watch the video a few times, or try to solve these questions by yourself first, and if you get stuck, then try to see what I did to get to the next part. These videos are meant as a supplemental tool, and not a substitution for a textbook/professor. Thank you for the feedback!

[@shankylezapanta1464]

My approach to his every vid is to try to deeply understand the underlying concept and pause right at the very beginning of each example and try to think thoroughly on how to solve it myself. Give yourself some engagement on critical thinking rather than just "watching". Critical thinking will give you a solid comprehension of the topic that will stuck on your mind that would greatly help you on your exam and even after semester, you will still understand the topic. Works for me 100% I usually answer his examples on all statics vids 95% before he explains. Try it urself :)

[@abdiqanicaligalol6192]

Thank 👍you for your excellent presentation

[@QuestionSolutions]

You're very welcome!

[@jasondinosoccer]

Another amazing video, thanks for the extra help with studying this stuff! 🙌

[@QuestionSolutions]

My pleasure! Keep up the good work with your studies.

[@jeffkwin3129]

Great video, but I got a question at 5:11, shouldn't the forces 2kN and 9.5kN only apply moment on the components perpendicular to the truss AH, because you also did that for Fbg?

[@QuestionSolutions]

The 2kN force and the 9.5kN force are perpendicular with respect to where the moment is calculated. If you imagine your finger at the location where the 2kN force is, and push, will the truss spin about our moment point? It would right? So it will create a moment. I think you're assuming we are doing the moment about the whole member AH, which is not true. We are calculating the moment about the pink dot, just point H. When we calculated the moment about point A, only the y-component of force BG creates a moment. But notice that the 2kN and 9.5kN force only have y-components, they are vertical, so it will create a moment about point H.

[@chumpmark3884]

This man is a legend

[@QuestionSolutions]

Thank you very much!

[@sumitrohan1839]

Watching this before exam is worth :)

[@QuestionSolutions]

Best wishes with your exam! :)

[@mohammadashu8984]

Really really great content..... I also want to learn such kind of animation ....can you please tell me how you do it? It would be great help to me....love from India.

[@QuestionSolutions]

I use after effects for animations. There are tons of really good tutorials on youtube, so please take a look :)

[@mohammadashu8984]

@@QuestionSolutions thanks a lot... The very first channel which I shared on my social networks.... Keep doing...... You will certainly hit the market.. 😀

[@QuestionSolutions]

@@mohammadashu8984 You're very welcome. Sometimes, Udemy has free courses on after effects as well, so keep an eye out. Thank you so much for the share, I appreciate it. 😁

[@tunes_nirvana]

Amazing Video, All doubts cleared

[@QuestionSolutions]

Glad to hear that :)

[@RathodAbhishek-p7b]

thank you sir for such a good explaination

[@QuestionSolutions]

You are very welcome! I hope it was helpful to you.

[@alijawad432]

For question one I know u take thr moment at Point B but if we took the moment at point H, we would have two unknowns, Fbc and Fbg horizontal component both causing a moment. How would u solve it then?

[@QuestionSolutions]

The whole point of taking a moment about a specific point is to eliminate as many unknowns as possible. If you have 2 unknowns after writing a moment equation, then you'd need another equation, probably for vertical forces or horizontal forces. Try to take moments about points that lead to direct answers.

[@markshevchenko7482]

thanks for the content, why in second to last problem we only consider that in F there is Fy component why not Fx as well?

[@QuestionSolutions]

Please provide me with a timestamp at the location you're referring to. I will take a look and explain it :)

[@ZexMutsawu-nw2ov]

6:28 in your explanation you said that only the x component of force BG can cause a moment about D but on the working you used Sin instead of Cos. May you please clarify

[@QuestionSolutions]

So my guess is, you assume cos is for x and sine is for y. This is fundamentally wrong, and you must, absolutely must, remove that idea from your head. You have to look from the perspective of the angle every single time. Here, the opposite side to the angle gives us the x-component, and sine is opposite over hypotenuse. So you need to use sine. To get the y-component, which is now adjacent to the angle, you need to use cosine. See this video, it's less than 60 seconds and you will see what I mean: kzbin.infovynnKlJD_Jo?feature=share

[@ZexMutsawu-nw2ov]

Noted thank you ​@@QuestionSolutions

[@QuestionSolutions]

@@ZexMutsawu-nw2ov Awesome. Best wishes with your studies. Let me know if you need any further clarifications.

[@NK-iy6if]

God bless you! your videos are extremely helpful! Thank you so much!

[@QuestionSolutions]

You're very welcome! :)

[@MrStepBro]

Throughout all the Truss videos you talk about assuming the way the forces are acting and just back tracking if they are negative. Is there an intuitive way to always guess the direction correctly?

[@QuestionSolutions]

The intuition comes from doing a bunch of questions, in other words, experience. By the end, you should be able to look at a truss and know which way the forces are acting and be able to locate 0-force members. Also, it's not really backtracking per say when you guess wrong, you just change the direction of the arrow and make your value positive. The magnitude of the force is always correct, it's just a matter of whether it's positive or negative.

[@MrStepBro]

@QuestionsSolutions gotcha its just on my exam, we have to draw a free body diagram for a grade, and its online so its kind of a pain in the ass. So I guess a better strategy would be to mess with the free body diagram last and solve the problem first so I already know what direction the forces should be before putting them all in.

[@QuestionSolutions]

@@MrStepBro Ah, yes, it probably would be better to do it the way you mentioned.

[@ngsbsad5502]

At 2:00 why there's a two forces in joint A, there's already a 2kn downward load why we have to put Ay in solving moment

[@QuestionSolutions]

That's a support reaction. So it's a pin support there, and that means there is an Ay component along with an Ax component. However, the ax component do not create a moment about point E.

[@sayeedahmad8594]

Such a good video. You just earned a subscription. Keep them coming!

[@QuestionSolutions]

Thanks for the sub!

[@AbdeenzRock]

for when calculating F(BG) why didnt you do Summation(y)? why did you have to take the moment at A?

[@QuestionSolutions]

Please use timestamps, I don't know where you're referring to. Thanks!

[@brianandremacaraeg6781]

You are my hero! Could you also make a playlist about Strength of Materials?

[@QuestionSolutions]

Yes, that is also on my list to do :)

[@ElCrankoPunko]

@@QuestionSolutions pls do it soon. love your videos btw

[@QuestionSolutions]

@@ElCrankoPunko Unfortunately, Strength of Materials won't be done for some time. The next topic is thermodynamics. I think there are a lot of videos on KZbin about material science, I hope they can be helpful.

[@ElCrankoPunko]

@@QuestionSolutions cool man. eagerly waiting for thermodynamics videos :)

[@QuestionSolutions]

@@ElCrankoPunko :)

[@gappity]

thank you for this, the best explanation so far.

[@QuestionSolutions]

You're very welcome! Best wishes with your studies :)

[@ayayayayrand]

how do you assume the direction of forces, like how do you determine where will the arrow point at? btw great vids man very helpful

[@QuestionSolutions]

That's completely up to you. If you watch this video, I go over how that works: kzbin.info/www/bejne/laOuYWWkmrR5Z5o

[@REMythic7]

For the vertical truss, does that mean member BF doesn't need to be there since the force is 0?

[@QuestionSolutions]

In real life, no, because they are there to help with rigidity and stability. Sometimes, they will carry a force if the conditions of the bridge changes. lastly, they add to the aesthetics as well. People don't like seeing parts "missing" off of a bridge 😅

[@rpian1999]

@@QuestionSolutions Hello! How come F bf is equal to 0 when the x component of Fbg is acting on BF and also 10 kN is also acting at BF? I want a solution to find Fbf using moment method.

[@QuestionSolutions]

@@rpian1999 Please give me a timestamp so I know where to look, thanks!

[@rpian1999]

@@QuestionSolutions 7:38 time in that video where Fbf is being determined.

[@QuestionSolutions]

@@rpian1999 So BF is a zero force member, that means it doesn't carry a force. The forces applied at B are carried by the other members, not BF. If you want, you can look at point B and do the equations, you will still get 0 for member BF.

[@Kouka2005]

Super Helpful

[@QuestionSolutions]

Glad to hear :)

[@gims6968]

Thanks for the video! But I have a question for finding force BF in the second problem. If we would have isolated joint B, equilibrium along forces at x would be 10kN - 45Kcos(45) - F(bf) = 0. Hence i thought that force BF would not be zero. Im confused how this works ://

[@QuestionSolutions]

I encourage you to actually isolate for joint B and solve this problem. For your equation, you should have 4 forces. The 10kN, BG, BF, and BE for horizontal components (along x).

[@dirtyharrysgun2020]

Thanks man, you're the best

[@QuestionSolutions]

You're very welcome!

[@Wallerrrr]

i have a question, in the first question when you were calculating moment about point H, why did you include the 9.5(2) and -2(2)? I thought the only force perpendicular to point H would be fBC and the x component of BG? Please clarify, thanks!!!

[@QuestionSolutions]

So both the 9.5kN force and the 2kN force are perpendicular to point H. Imagine you move those forces up to be aligned with point H, so straight up. Now you can see it a bit easier that they are indeed perpendicular. Another way to see it is to realize these forces are vertical, and will cause the object to rotate about point H, so it must create a moment. Force FBC and the x-component of BG is NOT perpendicular to point H. That's why they aren't in the equation. I think you are confusing perpendicular with parallel. Please draw a big diagram on a sheet of paper and really carefully look at what forces are perpendicular.

[@annerivera176]

Great video, thanks! Just a quick question, I tried solving the 4th problem but using the other side of the cut and the answer is different. Is my answer wrong or is it possible to have different answers when using different equations?

[@QuestionSolutions]

Regardless of the cut you use, or which side you use, you should end up with the same answers. This can be verified by solving the whole truss. There is probably some numerical error. :)

[@alifkri6719]

You is the good teacher , god bless you inshallah 👏🏻🤍

[@QuestionSolutions]

Thank you very much, I really appreciate it.

[@XIVRedd]

Thank you soo much this video really helped me !!!

[@QuestionSolutions]

Really glad to hear that! Keep up the great work :)

[@mastfamastfa1256]

7:33 can you explain how ? we have 3 other forces in the x direction 10 + 10 + 5 + BF = 0 BF = - 25

[@QuestionSolutions]

Where did you get those forces from? So when you look at a joint, you only look at that joint, you don't care about what happens at the next joint over. There are no other forces applied at joint F other than vertical forces. I think what you're doing is translating forces from other joints to this joint, but remember, when we look at a joint, it's isolated. That's why you draw a separate coordinate system about that joint. At 7:33, focus on the right side of the screen and look at the forces at that joint. :)

[@mastfamastfa1256]

@@QuestionSolutions ❤

[@QuestionSolutions]

@@mastfamastfa1256 ❤

[@drvirusg9046]

sir can you please recheck the video at 3:39 minutes because I think the answer at this point is 0.5 rather then 1,5,

[@QuestionSolutions]

The value shown on the video is correct. 2 x tan(36.87) = 1.5. I am unsure how you arrived at 0.5 but if you need help, please show your work. Thanks!

[@OMKAR-lj8ci]

well explained

[@QuestionSolutions]

Thank you very much!

[@milesbrack9188]

For the question at 5:25, why does the force in member BA not equal the reaction force from point A? I found a reaction force from joint A of 45kN when taking moments about point G, but the force in member BA is 50kN.

[@QuestionSolutions]

The cut was made above the reactions so they were not needed. No calculations were made to figure out the reactions at A, or G. Also, where did you get that BA is equal to 50kN? At 7:07, we find that BA = 45kN.

[@milesbrack9188]

@@QuestionSolutions Thanks for your quick response! I wanted to verify that the force in member AB equaled the vertical reaction force at A. I understand that it is not directly relevant to the section method. I just checked my calculations for some of forces in the Y axis, and I totally forgot to include the 5kN on point E. Now I have the correct solution for AB. Thanks again for the brilliant video!

[@QuestionSolutions]

@@milesbrack9188 Okay, glad to hear it was cleared up. Keep up the good work and best wishes with your studies :)

[@sevgipnar5261]

In the first question can we use which equation we want? I mean when we use moment or Fx=0, Fy=0. We used only moment equation in this problem.

[@QuestionSolutions]

You can, but try to use ones that give you the answer the fastest.

[@sevgipnar5261]

@@QuestionSolutions okay thank you

[@79elcapitan]

@10:37 shouldn't the answers be in kN not N as the original forces are in kN? Great videos and easy to understand and work through to show workings.

[@QuestionSolutions]

Yes, it's a typo. 👍

[@squareroot1698]

Can you kindly explain why you used "sin" operation for x components and "cos" operations for y components....? i always thought we should use sin for y and cos for x...

[@QuestionSolutions]

Please see this video, it's less than 60 seconds: kzbin.infovynnKlJD_Jo?feature=share

[@invisiblenavigateur315]

Absolutly the best truss video woooooow great

[@QuestionSolutions]

Thank you, I hope it was helpful to you. Best wishes with your studies!

[@ahmedabaid7090]

VERY unimportant as it has no affect on the method but on 9:13 I think the answer is 42.5 not 45.2 but correct me if I am wrong

[@QuestionSolutions]

Yes, you are correct. There is a typo there. Good catch :)

[@danisulat6762]

YOU ARE A FUCKING HERO DUDE!!!

[@QuestionSolutions]

Thank you very much!

[@bii_gii]

You are the best! Thank you so much brother

[@QuestionSolutions]

Happy to help and best wishes with your studies!

[@SakthiVel-vm6ub]

Top much explanation sir❤

[@QuestionSolutions]

Thank you very much! ❤

[@bolingonraffyt.6154]

I think sine is for summation of Fy and cosine is for Fx? Correct me if im wrong.

[@QuestionSolutions]

You are wrong, do not fall into that pitfall. I am not sure why students tend to this think way, but they are NOT related to Fy and Fx. It's all based on the side opposite to the angle. Please take a look at this video: kzbin.info/www/bejne/hKOvZpdjZ6iUmLM

[@jr1753]

Just wondering for moments how do you determine the direction for them?

[@QuestionSolutions]

Please kindly watch this video: kzbin.info/www/bejne/h3-xn4OQa52Giqs So initially, when writing a moment equation, I pick clockwise to be positive (this is an assumption). So you're looking to see, if we apply a force at a location, will that member turn clockwise about the point where we are calculating the moment at, or counter clockwise. If it's clockwise, its positive, if its counter clockwise, its negative (because it's opposite to our assumption). The first 2 examples in the link I provided will help out a lot with directions.

[@hunggaming4555]

Thank you bro

[@QuestionSolutions]

You're welcome!

[@krizzelannaquino4981]

why the problem 3: DC=125 kN (C) is compression? And not Tension?

[@QuestionSolutions]

Force is coming towards the pin so it's in compression.

[@imansalim3874]

Check me if I am wrong,you said if we chose the moment at 1 point then we can eliminate the action force acting on it,but I don understand in 2nd example at 6.30 ,which moment at point D ,the 5 kN still considered?Tq

[@QuestionSolutions]

If you're referring to the top most force, applied at D, that is NOT considered when writing a moment about D. Please carefully look at the color coded boxes and lines, each corresponding to which moment is being calculated. The 5 kN used for the calculation is the one applied at point E.

[@imansalim3874]

@@QuestionSolutions ohh I see it now,my mistake.Thankyou

[@QuestionSolutions]

@@imansalim3874 Glad you got it :) Best wishes with your studies!

[@sabahhabas]

Thank you i understod verey well

[@QuestionSolutions]

Glad to hear!

[@kingzzzmen7242]

9:07 could you have used the moment at F and still got the same Force HI?

[@QuestionSolutions]

You can find the values using any moment location but try to use simple ones since you want to make your life as easy as possible. So go for the one that eliminates the most unknowns or leads to a direct force value.

[@sapphireblue9209]

Hello, thanks a lot for this video. It was very helpful. I have a question: 5:35 can we cut the truss through BF, AG, AB? basically diagonally

[@QuestionSolutions]

You can pretty much cut it anyway you want (as long as you have enough info to solve it). The cut should be made to figure out the unknowns you want, so try to cut the ones you need to find. So yes, you can cut it diagonally 👍

[@sapphireblue9209]

@@QuestionSolutions ohh I see, thanks a lot and THANK YOU SO MUCH FOR THE INSTANT REPLY I admire your dedication💙💙💙

[@QuestionSolutions]

@@sapphireblue9209 You're very welcome. Best wishes with your studies!

[@sapphireblue9209]

@@QuestionSolutions thank you very much!

[@Xav-p3z]

Bro, thank you

[@QuestionSolutions]

You're very welcome!

[@hananhemed4772]

Thank you for ur help 🤗👏

[@QuestionSolutions]

You're very welcome!

[@fritszieboy7805]

thank you needed this

[@QuestionSolutions]

You're very welcome! :)

[@fatemaalshehhi1144]

Thank you so much. I have a question regards problem 2. To find Force AB can we use the moment around F? and why did you use the sum of Fy not continue using the moment to figure out the other sections. I used moment around F to find AB but ending up with different answer. Thank you

[@QuestionSolutions]

Can you please give me a timestamp so I can look at the spot you're referring to? Many thanks!

[@anakhash190]

first thank you very much for the incredible job. But I got question! why didn't you give some 3d examples about this lesson (trusses)

[@QuestionSolutions]

You're very welcome. The reason is that usually, 3D examples aren't covered in first year courses. Maybe in the future, I'll make one :)

[@anakhash190]

@@QuestionSolutions oh that's why. I'm studying at TuDelft university, we have to study everything also the friction, potential energy, virtual work, and centroid (this is for the first quarter in the first year). But lemme tell man, you did a great job I will do the resit and I am watching your videos they are very well explained, instead of looking at the lectures again and again. thanks man and happy new year.

[@QuestionSolutions]

@@anakhash190 Yeah, I think it depends on the university. Some of them are covered in 2nd year courses with a lot more in-depth details and questions than what the Hibbler book covers. Either way, I wish you the best with your studies. Keep up the great work :)

[@darrenwood3826]

Can you do a video about space trusses?

[@QuestionSolutions]

I will add it to my list, but it probably won't get done for some time. I am still working on thermodynamics videos.

[@stevo_cars]

6:15 is it also possible to find the moment about point C since it also helps us get rid of F-BA?

[@QuestionSolutions]

Yes, you can write a moment about any point you want. The goal is to eliminate as many unknown forces as possible.

[@quh2828]

6:31 Why the FbgSin45(8) is positive but not negative? Thank you🥺🙏🏻

[@QuestionSolutions]

So if you try to imagine the x-component of FBG, it will be pointing to the left. In other words, it will try to make this whole truss turn clockwise, and since we picked clockwise to be positive, it creates a positive moment.

[@quh2828]

@@QuestionSolutions​​⁠ Thank you for your reply and explanation🥺🙏🏻, but I can’t imagine the x-component of FBG pointing to the left. I thought it points to the right😢Could you please further explain why it points to the left?😭🙏🏻

[@QuestionSolutions]

@@quh2828See this diagram, I've drawn just point B so you can see the force and it's components. drive.google.com/file/d/12S2auvgrdjIPVzI8UhO1KHartq6aIhM8/view

[@PasantAssem]

thanks alot'

[@QuestionSolutions]

Happy to help!

[@Khromax]

I don't understand how do you know the direction of the force based of the positive/negative value? In the first example the value was positive 2 times in a row. In the first situation it was compression, in the second it was tension. How did you assumed those?

[@QuestionSolutions]

Please kindly watch this video first: kzbin.info/www/bejne/laOuYWWkmrR5Z5o Especially the introduction, where I explain how to determine whether things are in tension or compression. If, after you have watched it, and still have trouble, please let me know and I will do my best to help you out.

[@bashirullah4512]

Really nice vedio Sir I also want to learn such kind of annimation ....can you so please tell me Or provide some vedio leink .I will be very thankful of you

[@QuestionSolutions]

I use aftereffects for animations. If you google or search on youtube "after effects tutorials" you can find lots :)

[@bashirullah4512]

@@QuestionSolutions thanks you are great 👍

[@QuestionSolutions]

@@bashirullah4512 Thank you 👍

[@la_silenciosa_maria]

so every slope needs to represent vertical and horizontal components?

[@QuestionSolutions]

Sorry, I don't understand your question. What slopes?

[@emmanuelboateng1055]

When are you starting with fluid mechanics

[@QuestionSolutions]

Not sure, probably not for some time. I have to finish thermodynamics first.

[@Matthew-McCallister]

You are the best!!!

[@QuestionSolutions]

Many thanks :)

[@EfirDop]

I confused in part 7:20 b/c the force BC=0 is it correct??what abt the external force 10kN

[@QuestionSolutions]

Sorry, I don't understand your question. We didn't calculate force BC? Did you give me the proper timestamp? Regardless, all values shown are correct, except at 9:08, where force F_HI = 42.5 NOT 45.2.

[@XIVRedd]

QUESTION : at 8:23 why didnt we divide height over base? Like 1.5/2???

[@QuestionSolutions]

Divide it by 2 to get the angle or to find what?

[@XIVRedd]

@@QuestionSolutionsdont we usually do Tan(angle)=(height/base) ??? Our height is 1.5 and the base is 2… why in the video we did the opposite…like base over height…sorry for my bad explanation

[@QuestionSolutions]

@@XIVRedd That's incorrect and you should remove that thought from your mind. Instead, remember, tan = opposite over adjacent. So you look from the perspective of the angle, and look for the opposite side to the angle. Here, that's 2 m, and the adjacent side is 1.5 m. While we are at it, remember this too. Sine is opposite over hypotenuse and cosine is adjacent over hypotenuse. Always look from the perspective of the angle and look to see what side is opposite to it and what side is adjacent to it.

[@XIVRedd]

@@QuestionSolutions I’ll memories it right now so it doesn’t get me confused…thank you soo much sir :)

[@QuestionSolutions]

@@XIVRedd Great! If you have any other questions, let me know. Keep up the good work and best wishes with your studies :)

[@brienyeboah1497]

Can you please enlighten me on why force BC and BG would be eliminated when taking the moment at B. I am confused.

[@QuestionSolutions]

Their lines of action go through point B. The same as the 5 kN force, and the y-component of force HG. If you need a refresh on lines of action, please kindly take a look at this video: kzbin.info/www/bejne/h3-xn4OQa52Giqs

[@nancylu7644]

@@QuestionSolutions super helpful, thank you

[@steve20004]

just to be sure is it not supposed to be cosine on the second question Fbg since the Fbg sine will cancel at the pivot D.asking just to be sure

[@QuestionSolutions]

You are calculating your components incorrectly. Cosine would give you the y-component, in other words, the vertical component of force FBG. Sine would give you the x-component, the horizontal component.

[@judekirkcruz7177]

wowowwwww thank youu so muchhh!!!!

[@QuestionSolutions]

You're very welcome!

[@kevcopo]

Organic chemistry tutor of statics

[@QuestionSolutions]

Thank you very much!

[@noimosyni_0594]

thank you

[@QuestionSolutions]

You're welcome!

[@Julianzz_19]

3:46 PLZZ tell me how do you determine if its in cos or sin??? I understand the whole thing but always messed up the cos & sin part in the equation 😭😭

[@QuestionSolutions]

Please see: kzbin.infovynnKlJD_Jo?feature=share

[@cieloves]

thank you sir....

[@QuestionSolutions]

You're very welcome!

[@SavaRanya]

it was helpfull thanks

[@QuestionSolutions]

You're welcome!

[@muhammadsyaiful67]

at 8:49 , can we know wether we need to x eithr clockwise or anti clockwise because my answer 345 for fdc

[@QuestionSolutions]

It doesn't matter which way you assume it, if you get a negative answer, it'll be opposite to your assumption. So here, I picked it going towards the pin, but assume we did the opposite. Then the only thing that changes is that instead of -F_DCsin53, you would get +F_DCsin53. Which would yield a negative answer, and that means your assumption is incorrect. If you get 345, you made a numerical error, please double check your work.

[@steve20004]

can you help me with the second question.is Fbg not supposed to be cosine for the moment because the Fbg sine is going towards the pivot which will cancel.asking just to be sure

[@QuestionSolutions]

No, it's sine because that gives you the x-component. So you need to look at the sides from the angle. The opposite side to the angle gives you sine, which in this case, is the x-component of FBG. Cosine would give you the y-component, which wouldn't create a moment.