A community for students.
Here's the question you clicked on:
 0 viewing
agdgdgdgwngo
 3 years ago
An ideal liquid with density ρ is poured into a cylindrical vessel with cross section A1 to a level of height h from the bottom, which has an opening of cross section A2. Find the time it takes for the liquid to flow out
agdgdgdgwngo
 3 years ago
An ideal liquid with density ρ is poured into a cylindrical vessel with cross section A1 to a level of height h from the bottom, which has an opening of cross section A2. Find the time it takes for the liquid to flow out

This Question is Closed

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1324391218466:dw Ok you have this problem

agdgdgdgwngo
 3 years ago
Best ResponseYou've already chosen the best response.0quick analysis reveals that time is independent on the density rho, so thats one down

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1We can translate the units into units/m2 rho*v*g => rho*h*g m*g => rho*g 1/2*rho*v^2 = p*g + p*g*h So that's initially, but in the end h=0. We are gonna view this as a linear problem (not 100% true, but ok. A better assumption would be to take an integral over it). So at the end the formula is: 1/2*rho*v^2 = p*g To get the average velocity, solve this problem. Because you know the volume of the total box (A1*h) and now know the liquid flow (in m/s which multiplied by A2 becomes volume/s)

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1The average velocity can be found by combining both formulas: rho*v^2 = 2*p*g + p*g*h

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1Wher I say p, I mean rho ;P ... I mix em up sometimes

agdgdgdgwngo
 3 years ago
Best ResponseYou've already chosen the best response.0after we solve for v, what can we do to obtain ttime?

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1You translate V (m/s) into cuubs per second (by multiplying with outlet surface A2). Now you have a box with a fixed volume, that decrease with that rate over time

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1I don't usually work with inviscid flow, so maybe your teacher wants a more complicated solution, idk that.. this gives at least a relatively accurate solution

agdgdgdgwngo
 3 years ago
Best ResponseYou've already chosen the best response.0im stuck on the very first problem :(

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1Always draw before you start your analysis... It makes the problem a lot easier.. I think my solution is the one your teacher is searching for... But you might want to open your book to see if it's done there differently.

agdgdgdgwngo
 3 years ago
Best ResponseYou've already chosen the best response.0it was done quite differently :( http://ocw.mit.edu/courses/physics/801scphysicsiclassicalmechanicsfall2010/unitsanddimensionalanalysis/MIT8_01SC_problems01_soln.pdf

henkjan
 3 years ago
Best ResponseYou've already chosen the best response.1They've made more assumptions than I did. Haha, dimensional analysis, I've had that a long while back. I don't think I'll be to good at that. I only use it as a check, not as a way to work ;P

agdgdgdgwngo
 3 years ago
Best ResponseYou've already chosen the best response.0Yeah I don't even understand how they could pull out those assumptions.
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.