Fluid Mechanics: Fluid Statics Examples (7 of 34)

[@zacharydavis4398]

Thank you for spending the time to make this content Dr. John Biddle, Mr. Matt Desalvio, Mr. Michael Olmos, Medivision production and the entire CPPMechEngTutorials channel staff. It is appreciated. Comments left in this thread were made prematurely and were all addressed by the end of the video. Regardless, great content all around. Thanks

[@dantesinaguglia3474]

Thank you For these videos. Your lecture structure and teaching methods are extremely efficient compared to my professor. I haven't attended a lecture for fluid mechanics in a month. Ive only been watching these videos and practicing.

[@bhradramazani]

1:17:58 The equal sign initially there was correct. The minus sign gives a totally different answer. The solution also has it with an equals sign .

[@sagarpuri7838]

I also think initial equal sigh was correct because it follows law of buoyancy.

[@chichorro1000]

Nice class. Thank you for the videos. 7/34

[@youssefalnaser]

beautiful ✨

[@edwintan65]

at the end, Why was gamma1*h2*A2 MINUS gamma1*volume2 ; but not EQUALS? because when you solve for delta h, wouldnt the equation be altered subsequently as well?

[@MisterBinx]

Why are you only using half of the weight of the mercury if the entire shell is filled with it? The bolts are holding on to half the the shell weight but all of the mercury in the container.

[@akshays3572]

I am not sure which of the two methods you are talking about but if you consider the second method, that is taken care by the formula for the vertical component of Force for curved surfaces

[@tufailbhat3885]

At 42 min...you forget multiply radius 2 with area pi by 4 (.5)*2 (2)...

[@rtrt2889]

Great lecture!

[@ken-cf7tf]

in the first problem why is the shearing stress at the bottom of the cylinder neglected? should it be considered on the calculation?

[@porterd3160]

No slip condition. The outside cylinder doesn’t move. So the liquid on that surface is not moving. Thus it is experiencing no shear force.

[@Mujtabh]

Can you help me with that?

[@MisterBinx]

The only thing I can think of to explain it is that you are using gage pressure in the middle and since you're ignoring the atmospheric pressure you also ignore the weight of the fluid on the top half.

[@nagoenes]

You saved my semester

[@CPPMechEngTutorials]

All in a day's work for Professor Biddle.

[@adityakushwah4980]

In the very first problem torque should be integrated because radial distance is not constant i.e dT = dF×r

[@alternatifoyuncu8026]

can anybody help to find the manuel solution forthat book 7th edition

[@zacharydavis4398]

38minutes in ... hmm didnt he just describe how pressure with respect to depth is constant across a horizontal plane in a previous video (in this example @ ~38minutes how he explains his set up for finding F(rv) was verbally described incorrectly, because what he said is not the same thing as saying the pressure of the fluid above said area.. even though in this case, it will eventually equal the same thing). Meaning the F(rv) would equal the total weight of the water above the projected area above the curved surface (i.e. 0.5*0.5*2 plus [(0.5^2) minus (1/4*(pi)*0.5^2)], which ends up equaling the same thing as the train of thought that he utilized in this video @ ~38mins into this video, but the way he describes it contradicts his chosen methodology/discription in his previous videos within this series. Just saying. It turns out in this case, it

[@RobertSpaw]

In the first problem, should the r_0 - r_i be switched in the shear stress?

[@AmeerHamza-bc4fh]

The distance should be positive, that's why he used (ro-ri), a positive value.

[@ken-cf7tf]

@@AmeerHamza-bc4fh why he can do that? should it be r_i - r_o since the corresponding velocity at those points is v - 0? if the velocity gradient turned out negative, then that just means that velocity decreases which is the case in the fluid?

[@AmeerHamza-bc4fh]

@@ken-cf7tf yes, you are right. I think Prof did mistake here. If velocity gradient is negative, then tau (shear stress) is also negative, which would mean that its direction is opposite to that of applied shear force F. Applied stress and internal shear stress should always be in opposite direction.

[@ken-cf7tf]

@@AmeerHamza-bc4fh also id like to ask does the bottom of the cylinder experiences shearing stress? if yes, why is it neglected?

[@tomasmackeon399]

@@ken-cf7tf yes it does, the problem is you'll have to use integrals to solve that and integrals don't seem to exist in this course

[@zacharydavis4398]

Never mind about my previous question/comment. I'm an idiot. @ ~40minutes into the video he in fact does what i previously said when he solves the same problem utilizing the second methodology. Verbally it still remains consistent that he was describing the first method in a manner that verbally contradicts what he has said in a prior video to this, in regards to the 2nd method he utilized in this particular resultant force calculations on a curved surface/etc

[@furkandurdu9615]

hello, i got a question about the problem which the professor deals about 1:00:00, why are we not taking into account the reaction of the ground to the gate in our calculations or in the free body diagram ?

[@grethuman]

Hi Furkan Durdu, I think that's because actually water supports the gate not the ground, so we don't account its reaction.

[@joshuapancuelo1942]

7:03 why was ri cubed, not squared?

[@joshuapancuelo1942]

oh nvm, they corrected it at 9:23

[@Mujtabh]

Can you help me with that?

[@zacharydavis4398]

7:26.. anyone else confused, shouldnt T be a function of r^2, not r^3 ? Or am i completely off

[@Mujtabh]

Can you help me with that?

[@juniorjay001]

it's ok, just a mistake. it is supposed to be squared

[@seandylannagayal]

how did he get such a high resultan value when gamma water is 62.4

[@UwinIquit]

SI units

[@SamidBatista]

Sos un groso💪🏾

[@CPPMechEngTutorials]

Sí

[@notadestinygun6556]

LMAO this guy gives his students 4 pages of equations AND lets them use 2 sided piece of paper with whatever they want on it. Meanwhile at Rutgers.. Prof. Sahi won't let us bring anything.. and won't be giving us equations either.

[@kgbkgb7616]

This is a real engineering professor though