 Okay, hang on to your hat, we are going to amplify our moments and then we're going to correct the amplification because sometimes we get a little over enthusiastic. You must be careful though because sometimes the correction gets a little over enthusiastic. So when you find out the plastic moment that you're good for is 200, I'm afraid I may have to amplify it. Let's say your request is 200 because of legitimate things. But then when you try and correct it you may find that it's corrected below the original number. That's not fair. What we've done so far didn't take into account and we admitted it. The fact that all columns when you get them, they've got a little bit of bend to them. We took that into account with the .866 times Timoshenko's value for how much buckling load you can put on something or how much load it'll take. But the problem is that little .866, what you didn't take care of is when you put the load down the axis you didn't add some moment in here p little delta. Sometimes it's not so little and so we need to discuss the fact that in the box it's got a little delta to it unless it's very rare. And when you put a little load on it that delta gets bigger because you've got an added moment p delta. Those are called secondary moments. But even though they're secondary they can sometimes get quite large. There's for all with the simplest of structures. Oh there he's talking about analysis. Almost always you're going to have a computerized analysis to get these bending moments and axial loads. And he's going to mention that all he's going to do is going to tell you he's assumed someone has done that and he's going to give you the results of that analysis. Now there's two problems. Number one I just mentioned is p little delta. That's if you're in a braced frame because you see the top and the bottom are not displaced with respect to each other. But in some of the frames where they're not braced internally or externally they not only will have a little offset when they're in the box when you put the load on them they will sway to the side. Are there some real loads that push it to the side? And now we're not talking about p little delta. We're talking about the possibility of p times big delta. So one is without side sway permitted. You're used to that. And one is we'll analyze them if side sway is not restrained. It is permitted. If you got a computer program and you put the analysis in the program and they put the loads on this frame right here I've shown them at the corners but there's probably some uniform loads and things maybe some will concentrate it. If you put that in the computer and he comes back in first time through says the moment is this at this joint because of the uniform load it's this at this joint the moment down in here to a moment down in here and then he quits that's called a first order analysis. If on the other hand when you put the load on there he sees the load let's say is off center and because the load is off center towards the right this whole thing tends to sway to the right or he goes in looking and he finds this horizontal load that's been stuck on there due to wind and it has moved to the right. He put all those loads on there and he got the moments at these points. But what he didn't take into account in a first order analysis is the fact that after he got the answers this point deflected. He says yeah I did I told him about that I say I'm not asking did you tell them that this load and the other loads cause that sway. Once you calculated that sway did you change your answer because you now have AP big delta. He says no I guess if they wanted to do that what they would do is they would come back and they would bend the member themselves they would tell me that the initial position of this thing was not 0 30 feet they tell me it was 0 30 feet plus 0.6 inches. They could do it that way. I say okay thanks a lot. That's a second order analysis. Now a lot of the computer programs today are set up to do that. Before they report to you they find out that this load didn't call did cause a deflection and then they put the load on the deflected shape first they put it on the undeflected shape then they put it on the deflected shape they run it again and then that load causing this p delta causes more moments in here probably causes more deflection and therefore he comes back says whoops it moved again and after three four times he says okay it's not moving enough to matter I quit and he reports the answers to you that's a second order analysis. Second order analysis is pretty good because you don't have to do any of the stuff we do here but if you're just doing regular old designing of something and you have a first order analysis then you need to correct your moments for these effects. Number one p little delta number two p big delta. There are three methods people been using them for years and finally the specifications had to sit down and say okay well there's 19 of these things let's let's get the three most common see if we can't jam everything into one of two or three methods the way they do business and then approve those we say these are good so my mind's not in there so do your own thing you don't think it'll fall down and you're a registered professional engineer and you show me some theory but we didn't much like your way of doing business it's not one of the blessed three. Number one is called a direct analysis some of these will have some direct analysis in more than one but basically this method is called a direct analysis this is the only analysis where tassabee is used where the softening of the member is included it is a second order analysis that considers both p delta and p delta effects is also it includes if you only do a first order analysis then give me those moments and I'll give you factors to correct them so you get an approximate second order analysis they'll both be considered second order analysis they're both legal nothing anything ever fell down was done by that method in this direct method analysis we use our tassabee just like you and I did previously we use an effective link factor of one so that means we're not going to our g tables with this method you say well you know I don't know why we don't use G I don't know why I don't get that gift I don't know why I don't get to reduce my KL the way this is done you do it with K of one you are permitted to reduce the stiffnesses when you put them in and analyze them for moments but the K one is you K equals one used both in the analysis and the strength and more details as you might imagine by the ton 16.1 dash 23 is the spec 16.1 dash 5 20 look at that big number must be down in the commentary on this information tassabee is only used here these have become clearer once you see them right now just a broad brush stroke an effective length method it's covered in appendix seven this one is covered in appendix eight actually this one kind of breaks down into two pieces the first one here is little discussion on seven point one then in seven point two they discussed the effective length method to give a chapter four we did that and secondly this is in seven point three of appendix seven it's also requires second-order approximation of the frame compute the available strength as we discussed in chapter four and you use an effective length factor and you do not reduce the member stiffnesses so if you decide to use this method and the exam says did you account for tassabee you say I use this method of analysis it wasn't permitted third it's what they call a first order first order would be just like we talked about with a computer with no correction for the member being a little bit out of straight before you got there with your analysis simplified version of a direct analysis so it's not a direct analysis can be used when certain conditions are satisfied they tell you what those are in here it's covered in seven point three the member stiffness again are not reduced so the only one you do reduce them is the direct analysis these two you don't got some examples of all of them well he got examples because he'll tell you what method to use and how the moments that he gives you from a structural analysis you didn't have to run how they were generated and then you have to do your work in a similar manner so here is the direct analysis approximate second-order analysis if you have a real second-order analysis from a computer you you're through you just stick the numbers in and you go but in general we're talking about if you don't have anything but a first-order analysis and you want to approximate a second-order then he tells you the limitations tells you the calculation procedures we'll talk more about that later basically we're saying that your moment ultimate request is going to be some factor to correct for the out of straightness of the column or lateral loads causing it to not be straight multiplied times the m that you request non no translation in other words assuming the frame is braced if the frame is unbraced you have a second coefficient which would be multiplied times the moment in the frame the moments generated in the frame if the frame does translate I imagine a lot of ourselves going to be without translation if you know how to do this half in the real world it's not that hard to pick up on that the ultimate request also has to be done the same way it has P no translation there is no factor with it but because the thing if you allow lateral translation you see that big delta we talked about then you need a correction factor for it all the terms are defined then if you actually have to have b1 remember there was a b1 times moment no translation and a b2 times moment with lateral translation then this is the amount that you have to amplify it first off that's what you and I derived anytime you see an alpha in the whole book or anywhere else that's because we're trying to accommodate the allowed stress design people so that for us is always a one we insisted if you're gonna let them in okay but put any of the factors they need to come up to our standards cause it call it something that I can ignore it's always a one times the P ultimate here's your generic term P request divided by P Euler one I've never found a P Euler two but I'm sure it's in there just haven't run across it but it's P Euler one it is the Euler buckling strength of the column under discussion and then that gets overly enthusiastic sometimes and causes your moment to be really bigger than it needs to be and therefore for that purpose you have like a C sub B you remember where C sub B corrected the load down to bending down to something that was more like the truth it was like a Christmas present for the same thing here this thing this amplification factor may get kind of rowdy and here you can tone it down if you got this coming you can correct that number first place if you're having an amplification factor and you go in here trying to help yourself so remember that said B1M M no translation somebody's making you multiply that times a number if you're gonna correct it if you got that coming to you well that's fine but you got to be careful you don't want to take a correction factor this was derived worst case this one over one minus P ultimate divided by P E one that's the worst thing could ever happen to you and therefore this is a cutting that down if that number ever comes out bigger than one just ignore it you say thank you I don't want that present because that's making the moment when you multiply this times the moment making it bigger by the same token if this number comes out point three you multiply that times a an increase due to the buckling about that axis and the buckling about that axis is one point one before you corrected it well point two times one point one is going to be less than one so they say look this is a correction factor for your use for your gift didn't have to be bigger than one that makes no sense it's no gift by the same token if you take our amplification factor and you drive it down below one then when you go get your moment you say hey that's really wonderful this much moment is really there and I know only need eight tenths of it that's not right you can't amplify a hundred percent down into something smaller so this must be stopped at the number one where we're a one and there are one point six now we get more into these c sub m correction factors because life is not as harsh as we thought and you already know what an oiler load is pi squared e i star divided by k l squared the star is the flexural rigidity correction for the thing it'll have a tau on it if you're permitted to use tau there's your tau e i it's used in the direct analysis method and cows define here will be your amplification factor for p big delta effects b2 and it's something just like we have on the previous one now that nobody called my hand on it I usually make sure I go fast enough you don't have time does that look familiar to you doesn't does it you're used to multiplying the tau times e i to soften up the columns so they're not as fierce in trying to to roll the joint as they could have been but the point eight you never saw before and so you say point eight he says yes point eight factor accounts for the additional softening under combined axial and bending you remember we got a tau for bending only and if the fibers were bent badly enough and yielded badly enough the joint itself became soft and less able to rotate the joints to the the girders and the beams coming in we're still at a hundred percent strength but the columns themselves their tendency to be able to make the joint role was reduced now you know to not only have the bending you also have some compressive load on it so that makes the joint even softer and that's what it's for counts for fact factor counts for additional softening under combined axial and bending so a very quick run through here is an approximate second order analysis that was what you and I were calling case one won't go into it at all got a bunch of tables psi c sub m got me uses these tables in that case this is the only one that uses tau secondly you had the elastic limit I'm sorry you had the effective length that was our case two he describes it he tells you what has to happen here are your required strengths here are your available strengths so we of course is summarized all this nicely in your book then third was a first order analysis which you then will have to correct because it's just a first order analysis says required compression strengths required strengths available strengths all of these have commentary going with them must be an effective length method there because I see him going for effective lengths I see him still using these so they're all here mostly to refer back to as we go on commentary on first order analysis method we'll come back to that as we seek questions in what Tim Shinko tells us I'm sorry sugui tells us so here's how I'm going to have to amplify my moments number one I have a column which is very slightly out of shape it has an eccentricity in the box as you start putting load on it because P got multiplied times the in the box out of straight it has a moment at this point and it has moments all the way up here it's zero therefore due to those moments the thing starts kicking out to the side as you get up to the full load P it's kicked out I don't know how far but possibly not a small amount the equation in the box you can take whatever you want you can take a parabola you can take a sign you can't take a cosine you can take a piece of a circle to get on people who tried all kinds of things for grins you get pretty much this obviously if you say that deflection off of the straight line is a sine function those derived take derivatives nicely you integrate them nicely all that kind of stuff so there we always just pick a sign the times sine of pi x over l x bending how far down the roads you are e being whatever 305 says that if you take the second differential of displacement on a beam that has to be minus m over e i the minus sign is in there just for signs use because we like to measure when the beam is bent it bends above the axis then here's the beam here's a positive y direction it just keeps compression on top tension on the bottom doesn't change anything the moment in it I see is the load axial times y is zero that came in the box plus y the additional y not necessarily the maximum but this one that varies from zero to something in the middle that's how much moment is in there then I'll be able to take second differential of that and set it equal to that and why is zero I'll have to put in this equation to do the job done a thousand of these substitute that into the differential equation d squared y dx squared is minus p over e i I'll let you just look at that check it out rearranging gives you this ordinary non-homogeneous differential equation plug in the boundary conditions you find that some of the terms got to go away you find some of the terms can be valid plug those boundary conditions in and you get p oiler is equal to pie excuse me p oiler is one of the terms you get past where the i divided by pl squared I rearrange it you get p oiler over p where p oiler is the oiler buckling load plug that back into the equation for y here's your equation for the moment you know the moment on the ends is zero stuff like that maximum moment occurs at l over two and you get the maximum moment turns out to be m zero times one over one minus the load on the column divided by how much oiler said would take the buckle that column you want to see that I'll be glad to do it it's nothing to it but your eyes already roll up now much less if I start deriving something so look through that the point is your maximum moment actually in that beam because it had a little bit of out of round out of straight to it once you put the full load on it it's not any longer m zero it's multiplied times one over one minus the request for load divided by oilers load that's an amplification factor look when you start requesting the oiler load or the load over or the load is one one minus one is zero one over zero it's infinitely increased which for all intents and purposes when it collapses that's what it looks like so this is your moment amplification factor if you put a load on a non-straight member for us he says forget a lot of stress people the load P is your ultimate request and piece of oiler is the oiler buckling load now it's kind of interesting if you have a frame and a wide flange in that frame looks like that you ought to draw it in three dimensions if I can here's the column in your frame if you load it from the side as I would think you would probably want to do I don't think you very likely want to load it from the side about its weak axis you'll orient it such that it has the most strength for the money then you are interested in these terms you're interested in how much load is requested that would be piece of you regardless of what's going on except this oiler load now since you're kicking this beam out about the strong axis I need to know how far it went out due to the load on the beam about the x-axis so there's one of these that really goes with the x-axis there's one of them if you have to do this and put the load about the weak axis then you'd be using orders opinion of life buckled about the weak axis so here's an example as you want you to use that amplification factor you don't get to correct it yet you don't know how to compute the amplification factor for the beam column of example 71 you'll find it on in my notes on page 302f it was probably before that in the text but I'll give you everything you need here it was a 10 by 49 wide flange had I sub x of 272 I sub wife 93 if I wrote it down and realized it's not used it was 17 feet long it had a 10 plus a 17 service load I don't remember what but factored it turned out to be 25.2 and the guy told me that he intended to orient this column in this direction he gonna put the 25 to and force it to bend about the strong axis that makes sense there's not much sense and if you got a 25.2 external load and you got a column there you might as well do your bending about the strong axis so first we go to P Euler because we need all these terms here we need P Euler we need our request we need the initial moment and so on we don't need the initial moment to get the amplification factor P Euler is pi squared E I about the x axis divided by how long is it effectively about the x axis squared yx because this out of straight in the box plus the more out of straight that you see here due to this is causing a P delta not about the weak axis it's causing it about the strong axis because that's the way you put the load on it so that is I sub x I really should have written down I sub y just so you would see it's not I sub y its length is still 17 feet and it's pin-pin so it's still k is a 1 and it's still steel and pi is still pi this is Euler's opinion about how much load it would take to buckle the beam about the strong axis the fact that there's a lower load did probably already buckled it about the weak axis isn't my problem my problem is because the load came like this it deflected it about the weak axis my strong axis thank you so here's one drawn up here is somebody who knows his business put the load about the strong axis the axis of bending is xx due to the transverse load P sub e would be P sub e about the strong axis here's somebody who doesn't know what they're doing they say that's not true at all I mean I got this frame all tied to other things like that and that's I put them the welded to the other pieces so they will be bent about the strong axis in general use but this particular column happens to be on the corner of a building and it gets them when load from the side I don't that's nothing I can do about it I can turn it so that this doesn't buckled about the strong axis but when I do that I lose all the strength I need in the frame to carry the loads this one the bending is about the yy piece of boiler would be e sub y as opposed to e sub x continuing here's where I recalculated here were the service loads 1.2 dead 1.6 live turned out to be 204 that's on page 303 in your text and your moment had the numbers given it had a 25.2 kip load in the middle of the beam causing a moment request of PL over 4 that's the equation for the maximum moment in a simply supported beam with a single load at the midpoint 107.1 sadly this 200.4 is going to have to be amplified or the skinny the moment's gonna have to be amplified you don't have to mess with the load but the load times e is gonna cost some more of this kind of stuff called moments our amplification is 1 over 1 minus your request is 200 kips of load at an eccentric eccentricity I don't know how much but I've already handled that inside of the amplification factor divided by P Euler P Euler we must have got 1871 1871 kips of Euler strength about the x-axis therefore we crank it out you get a 12% increase I see why that's there the beam has got a little less eccentricity to it and it gets worse when you put the axial load on it and therefore the moments are really a little bigger 12% bigger than the numbers we had before at 107.1 times 1.12 120 you don't know where the 107.1 comes from this PL over 4 you can look on page 302 G it's got the tables for bending moments and beams PL over 4 now brace frames are not too bad because they only deflect little delta for example here is a pin pin beam a little bit out of square with a load on it kicked out a little more that's a P delta moment that you hadn't counted on you'll count on it by that correction factor but when the thing is unbraced like this one is you don't have a little delta you got a cap delta because you loaded it from the side and you had all these loaded had to be carried in compression down the columns and therefore your moment request when these things get big not just a little bit that started out out of square is the same as before B sub 1 M sub no translation plus B2 with the lateral trend of translation considered we're gonna get into a lot of those this information is on 16.1-237 because you're what everything is and we'll do some now back to members in braced frames you derive that amplification factor you consider it was kicked out to the side and nothing happened except everything got worse and because you can have moments on the end or you could have the lateral load we showed you earlier things are getting really worse that's about the worst case you're ever gonna have and I'll tell you where the maximum moment is going to occur in this case it's going to occur if that's M0 and that's in M0 due to symmetry it's gonna act in the middle it's at the center here you see the moment these are the end moments applied at the end here is your P delta effect but no where the maximum moment occurs and the equation that I derived is for that worst case oh well there are your yeah those are moment diagrams and deflection diagrams maybe we'll come back for them because I don't see the one for concentrated loads maybe they belong a little down the road I won't throw them away he says in the case we just looked at the moment is constant throughout the member and the maximum occurs at the center however if you have if you have this case that's a worst case because it was already deflected that way and the load caused the load caused it to go out more that way here the same thing it was already been a little bit this caused it to bend some more making the P little delta effect worse here you have two moments on the end this came from beams up here and beams down here wanting to roll you not letting them because it was welded to the beams and those moments are for example 600 and it was already kicked out to the right and you just made it worse you might say well I tell you what I'm going to do and we'll go check which way it's out of straight and I'll put the out of straight out of the box this way and we can put the loads on it won't go out as bad and I shouldn't be penalized as badly and pretty hard to guarantee that so that's the worst case that's the worst case that's the worst case this is not a worst case because the moment on this end kicked it out maybe that far and a third of the moment on this end kicked it out that much see how this is six inches and this is only three inches and here's another not worst case another not worst case as you still have the 600 and the 200 but one of them makes it kick out to the right as a matter of fact it by itself would make it kick out like that and then when you put this moment on it it was enough to drive it all the way back to the left that's not a worse case even if it doesn't go to the left even if it really goes like this that's not a worst case and so I understand your pain you say I need a correction factor for this you're making me do this I need a correction factor for this in fact I don't only want just a correction factor I want a big correction factor you got it for wishes our demand these are the moments you're going to amplify your C 305 moments the moments that come out of a first order analysis for example you have a moment on this end looks like this M2 you have a moment on the other end on the other end going in effect the other way see this one's causing compression in the left side this is causing compression in the right side so here for example the moment 600 and possibly 200 down in here the bending of that would be don't know what I'm getting these numbers okay 06 okay here are the moments due to the axial load so you just take the axial load and you multiply it times this delta this has no delta so you have no moment right around here because there's some delta you get maybe a hundred and sixty moment down in here you get maybe a hundred and fifty I'm just trying to say that looks like 160 that looks like 150 that looks like zero that's zero these are your moments due to the loading these are your moments due to the P delta together 600 plus 0 is 600 400 160 is 560 200 plus 150 is 350 0 0 0 and something down on this end maybe this is 200 except maybe I gave you the wrong numbers here maybe due to the EI of this particular column this is not 160 it's 560 and something and something okay sorry about that 400 plus 560 blah blah blah blah blah here the moment diagram you say kind of looks like this the biggest moment still on the end but if these numbers are price as big as I did because I forgot to multiply times two then you may find the maximum moment out here somewhere not at the ends oh this is getting ugly in a hurry really getting ugly and howdy I want you to hurt yourself but I do see you have your book open so that'll immediately rate the impact when you when you're not off there which you're supposed to be doing stay in the way to make sure I don't go to sleep I need a nap so since you don't even know where the moment occurs in this situation you're going to get a correction and it's going to be better than these corrections here where they're both the same way but whatever it is you don't know where that's going to happen remember this is your ultimate request says no it's not this was my ultimate request right here I say well what did you do did you brace the frame yeah so that was the only moment you're right that was your original request unfortunately due to your irresponsible application of a couple of load down the middle of the column I'm gonna have to amplify your moments did you have any lateral translation he says no I say no problem that's a zero but if you had some lateral translation in there from your first order analysis I need to amplify those moments too our b1 now it turns out to be the amplification factor with the correction that you insisted on because every now and then your beam didn't deflect as horribly as it could and this took into account the worst case C sub m was always less than one otherwise it isn't a gift because you're multiplying your moment times this and that would make your request bigger or and alpha is a one because alpha doesn't mean anything to us in this world in the real world and beta 1 if it's an amplification factor I don't care what this guy does or how far down he makes you go you don't go below one or you'll be taking the real required moment and knocking it down to less than a hundred percent for no reason can't correct it out of existence or is as he said before E I is the flexural rigidity with the star on it you get to use the point eight tasks of the E sub I E I the stiffness reduction factor you'll find it on page 306 F you find it in your manual on page 321 you'll find this exact thing this specification on this page here this stuff is on this page this stuff's on this page I try and annotate everything so you can quickly go to those pages so to go to those pages those are good probably to have tabs on so you can get to them quickly on a quiz town should be as a stiffness reduction factor where if you're less than 50 percent you remember you didn't have to do it or you couldn't do it wasn't permitted to reduce the stiffness to your benefit if it was bigger than that what is he doing here free on this I'm going to these tables all I got to know is you know where to go on the table and pick a number out of a table this gives the table values but he must be assuming I've lost my calculator or something or I've lost my mind because I'm gonna go get those out of the table now this method is acceptable to one of the three methods includes a direct analysis it requires the application of notional loans in other words one of the things that you have to do for the translation stuff is you have to account for out of plumbness of the columns this isn't anything we've seen before this is not the thing side swaying this isn't it's a little bit of out of straightness as it comes in the box this is when you built the dying thing it looks like this and you say man I did everything I could we had levels and transits and everything else I say well how did that happen he says I don't know it didn't happen till we got up to there and somebody tightened down that tie rod and the forces went down and did this it's acceptable but I need you to account for it I mean when you find it's bigger than a foot well you have to go fix it but if it's just within tolerances it still needs to be corrected and we do that by putting what they call notional loads on the floors some percentage of the load on the floor itself I didn't know what the word notional meant I never saw it before until got into steel the second method here we're going to discuss there's the notional loads these these things go off on it in interesting directions Google notional what is notional abstract theoretical speculative in other words not really there but you take some percentage of the floor load and you put it on that floor to account for the fact that that load causes some bending around in your frame and it accounts for the fact that it may not be perfectly plumb not real or actual ideal or imaginary all right effective length method got the same kind of stuff same kind of information same times you can use it here is that note on the point eight what it's for it is a fortune at this core and coincidence I like that notional somewhere in here somebody sent me to AISC 360 Dickens is AISC 360 now I don't see it off hand but I was sent there because I didn't know what it was so I stuck that in there Mr. Risa the structural analysis people they knew what AISC 360 and Risa 3d you can automatically apply your notional loads to the structure to comply with the code notional loads take into account of buildings actual out of plumbness by adding a destabilizing lateral load AISC 360 recommends either two tenths of a percent or three ten oh this is the guy that sent me to 360 I was still looking up notional loads and I want to know what the structural people thought the name meant here's what a structural if you don't know what Reese is I'm sure you do somebody probably made you run it before so then he came up with AISC 360 so I stick AISC 360 in Google this is the new AISC specification now available for free downloading and see AISC it's a combined spec 360 specification for structural steel buildings specs codes and standards so that's evidently I don't know maybe in ours already I got to go take a look at it and see if it's just a piece of our code or if it's something that's a little different all right doing the next one would take more than one minute see you next time and he's out of here anybody get run over anybody killed no you're better you're better you're better you don't listen to a word I say ever do you sorry I asked there needs to be a is there always a no there does not there no there does not in other words here is the structure let's say you put the load off center when I put the load off center you cause more moment in this corner than you do in this corner because it's over that way those two moments are not the same and the whole thing will flop over towards the load unless the load is symmetrically placed it doesn't have to be a real load there although many times it is well I wasn't talking about the column itself that's okay but what I was talking about is this frame right here if you put the load straight down the middle the thing will deform like this excuse me the form like this and if you put that same load over here because this has been so much more this joint didn't roll as much this kicks out further and causes a moment down here on this which is not equal to this one see right now kicking out those were both the same due to symmetry now then this one's bigger and the whole thing gonna flop over on its side kind of like that it'll move delta it won't be near as much if you say well now I'm getting ready to okay well now you gonna call some real deltas no this is the amplification necessary not actually see this one has no cn just yet and the reason is you didn't know how to calculate it cn will correct this problem this this is you think it was a problem because somebody amplified your moment and if you can cut that amplification down real theoretically true then that helps you in your design we're amplifying every moment in sight if you requested it we're amplifying it well it does not we don't know what that delta is we're gonna correct for the worst case that might happen to you yes sir I do I don't but I know it's listed on your syllabus in 346 also on the syllabus it has a thing there that says what are your chances of making a bc if this is your first grade then once your a and b grade and chances are from past years somebody made that grade and then what was their chance of making an a slightly reduced till 10% b or something go look at that I wouldn't say that because you may get hit by a truck and you know only be able to see a little bit when you take the quiz I don't know but I think I think all I can tell you is statistically and it really is gives you statistics in the past what the people made grades on quiz a and then of course they inquisbee what they made in the class you just get a q drop form but if you go to larry.tema.edu slash advising just put in there q drop or drop you know and it was control f for fine and it'll go down to q drop and it gives you calendars and gives you dates no no no you can do it 20 minutes for it to do but you've got to write fast okay sure you too