Jump to content


  • Posts

  • Joined

  • Last visited


  • Quark

Maqboole's Achievements


Quark (2/13)



  1. You are offered to finance a compressor , with a nominal interest at 8.2% compounded monthly. YOU PAY £590 PER MONTH FOR 134 MONTHS. Estimate the total amount of money to be paid . I would like some help in this ,i was m trying to do economics exams preparation .i would like can someone suggest me a solution or which site should be helpful. i would be very thankful, plz tell me if i m wrong what i did is i multiplied 11.2 yrs by 8.2 then multiplied £590. is that the correct way. Maqbool
  2. thx for your kind reply i have seen the link you sent me. i have seen the three formulas givens for the reynolds numbers but i dont understand whihc one to put as you see the 1st one is (density x mean fluid velocity x length of the object / dynamic viscosity ) if we see we have all the information we need to find reynolds numbers but we are also asked to find the dynamic viscosity . so that does not fit here all are to me used if the dynamic viscosity of is given . So i m still confused . waiting for your kind reply Merged post follows: Consecutive posts mergedOk this is what I have tried. I tried using the two formulas which come close to solving the problem. [math] u® = Vc [1-(\frac{2r}{D})^2] [/math] and [math] V = \frac{\pi*R^2*Vc}{2*\pi*R^2} =\frac{Vc}{2}=\frac{\Delta p*D^2}{32*\mu*l}[/math] if i use the 2nd formula, then I can calculate [math] \mu [/math] by making it the subject and doing the arithematics but the question, as I am sure you would have noticed by now, doesnt give the length or the pressure difference so I have more than 2 parameters missing rather than 1. Does anyone think that we can assume the pressuse as 1 atm (as it is constant) and the length as 1 m to get [math] \mu [/math]? If I do that I get [math] \mu = 7440 [/math] any help now please.
  3. Hi I am trying to solve this i really help .anyone i would be thankful. Fluid of specfic gravilty 0.06 flow in a long vertical 2.56 ^10-2 m diameter pipe with average velocity of 0.15m/s .if the preasure is constant through the fluids,what is viscosity of fluid? assume laminar flow/ i) Determine the shear stress ii) Viscosity of the fluid iiI) Dertermine Reynolds numbers i tried that i used my best to put reymonds number which is shown in following link. http://en.wikipedia.org/wiki/Shear_stress but i couldt . i hope you would be able to help me thx.
  4. hi i m trying do this question but i just dont understand how .i would be thankful if someone guides me . 1 :- The wall shear strees ina fully developed flow portion 0.3m diameter pipe carying water is 89 pa. dertermine the preasure gradient(Pa/m) if the pipe is a :- Horizontal b :- Vertical with flow up or c :- Vertical With flow down. 2:- A viscous fluids flows in a 0.10m diameter pipe, such that its velocity is measured 0.012m away from the pipe wall si 0.8 m/s. if the flow is lamiaar. Dertermine the center veocity Dertermine the flowrate/. Thanks .
  5. I didt get this answer at all i got something else this is the answer what we are told by our teacher. I wanted to use the formla A=Q/Utln For that i used the formula Q=m cp t then i used the formula for calculating tln = (t1-t2)/ln(t1/t2) we are given u now when we use that we dont get the right answer
  6. Plz help i just dont knwo how to solve it i just want a little help.thz Water at the rate of 68kg/min is heated from 35 to 37 C by oil having a specific heat of 1.9kj/kg C. The fluids are used in a counter double pipe heat exchanger, & ayhe oil enters the exchanger at 110 C & leave at 75 C/.The overall heat transfer coefficient is 320 W/m^2 C. Calculate the heat exchanger area. Answer is 15.82 m^2
  7. I have an other problem of the same nature now. I have understood the question well but i dont understand what formula should be used for the solution. Answer to the question is 7.579 W/m2 C 19 W Water at 50 C flows inside 25cm diameter tube such that hi 350Wm-2 k-1.The tube has a wall thickness 0.8 mm with thermal Conductivity of 16W m-1 K-1.The outside of the tube loss heat by free convection with hoof 7.6 Wm-2 k-1. Calculate heat transfer cofficient & heat loss per unit lenght to surrounding air 20C.
  8. Thz a lot i did get the solution & i did it right.Thz a lot if you would like i can explain that to you.
  9. first of all i would like to say my thank to CaptainPanic. In helping me in that question i would like to inform you that i did manage to calculate Gr & Pr .so i multiplied them & my answer came up as 3.08x10^9. What to do next now i am confused . yes i have the answer of the question answer is 1953 W. Can you help me Thx
  10. Hello i was working on my crousework on Thermodynamics of chemical engineering i would like to ask for help as i would be vevry appriciateable & other might benifi from it too the question is . Calculate the rate of hear transfer from vertical plate of side length 1m ,if its surface temperature is 500k & air flow by the plate due to natural convection,at a temperature of 300k. Data: For air viscosity ; 1.9x10^-5 kg m-1 s-1 specific heat capacity ;1.01 KJ kg-1 k-1 Cofficient of cubical expansion : 3.33x10^-3 k-1 Density ;1.165 kg m-3 thermal conductivity;0.0337 Wm-2 k-1 Gravity; 9.81s-2 For Lamimar flow: Nu = 0.59 [Gr.Pr]^0.25 For Turbulent Flow Nu=0.13 [Gr.Pr.]^0.33
  11. Intergrate by parts: ∫ x(x +1)^4 dx X . ∫( x+1)^4 - ∫(∫(x+1)^4) . dy/dx (x) X. (X+1)^5 /5 - ∫(x+1)^5 /5 . 1 X. (X+1)^5 /5 – (x+1)^6 /30 +C. This is the best I can go. Our A’level teacher says its fine to do it till here, but the book has simplified answer I want to get to. Could someone tell me how to reach to the answer of (5X-1)(X+1)^5 /30 + C. Help appreciated !
  12. This is the same problem I have actually. I think I need to relook the question and tell whether I have stated wrongly or not. My apologies if I have though!
  13. Hi there I hope you people must be doing well & if you be kind enough to please help me in my problem I would be grateful thx. Maqbool This is Physics question related to ideal gas Q: A uniform capillary tube, closed at one end, contained air trapped by tread of mercury 85mm long. when tube was held horizontally , the length of the air column was 50mm. when it was held vertically with a corked end downward The length was 45mm. find the atmospheric pressure. take g=10 Density of mercury; 14 x 10^3 How to solve it I tried it answer comes 5, use p=density x gravity x change in length Ans should be 1.01 x 10^ 5 (according to Mark scheme). PS. I need urgent help please, Ok don't give the answer but at least direct me to the solution! Thanks!
  14. Hi, I was wondering how you calculate bond lengths of HCl? Infra-red spec is an option which uses the mechanism of vibration to determine the functional groups. I want to know would this technique aslo be used to find the bond length of HCl? If so then should not HCl be in Gaseous state? Thank You
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.