Recent content by Jaydude

Question with diagram: Relevant equations: Attempt : My question: Using my method I got the wrong force , not sure if in this situation I can use Q=A1U1 = A2U2, hence maybe that's why U2 = 195 m/s looks wrong/too fast? I continue to use momentum conservation in the x and y directions...

Solved ! I see what you now mean, y bar is 0.6, distance between centroid and water line, that makes more sense, thank you! Just lastly if possible, what is that last equation in my original first post, with the integral sign? A more complex version of the Yp formula I used initially? Thanks!

Thanks , still can't get the answer though! Tried using y bar as 0.9 and 0.45. Do I use the water line as the reference line and measure y bar up to...where? Centroid, the bottom plate part, see what I mean? And Yep, my badly drawn diagram shows COP lower than centroid :)

1. The problem statement: A removable plate is mounted in the end of a swimming pool. The plate is 60cm square with the top edge 30cm below surface of water. Compute the force on plate and distance to centre of pressure below surface of water. 2. Homework Equations . 3. The attempt at...

After researching that I can see what you did there. For diatomic molecules which is air use Cv = 2.5R . To determine Cp simply use Cp/Cv = k, and usually k is taken as 1.4 unless given. I used this technique on other questions and it works every time so far, including the question posted above...

My mistake and confusion - sorry! I want to start again to make it clear for myself: In the solutions he uses Cp - R rather than Cv, why? We could have just used value for Cv like you said equal to 2.5R Ignoring above and continuing like the solutions, how is Cp value obtained? Eg you said...

I see, if R has value 287, then Cv is 717.5 - still not the value used according the solutions which is 1010 Jay

Stuck on part of this question regarding Cv value: I don't understand how one can get the value for Cv, I tried saying Cp - Cv = R (1) Cp/Cv = 1.5.so rearrange gives Cp=1.5Cv (2) Now sub 2 into 1 and that gives 0.5Cv = R But according to solutions that's wrong, Cv is 1010 and I can't get...

Bump. Can Someone point me in the right direction here/helpout with the solution? This is only for my practise and is not part of any H/W or Cwk and all of my friends are struggling with this Q too. Kind regards, Jay

I see my problem. V2 does not equal V3! Can't solve this, its getting annoying as I've spent hours ripping my hair out on this!

If V4 = V1 and V3 = V2, and we know V1/V2 = 16, then V4/V3 = 16 too...?

I see what you did there, but I get the incorrect answer, T4 should be 1379k What have I done wrong ?

But I don't have V3/V4 compression ratio :(

Sweet! But now I'm not sure how to get t4? And how do I apply that to get work done? I could use my equation (correct) in part b but I don't know what Cp and Cv are, how do I apply the constant 1.4 there? (I'm going to assume t2 is correct here...) Thanks!

I'm stuck on a question, part d below: My attempt: I reckon that T4 = T3 and T2 = T1, otherwise I don't know how else you can get T4 and T2...? Once I got first part of d, I reckon I could do efficiency using part c that I derived. I don't see where I'm supposed to use compression ratios...