# Flow rate calculation

1. Nov 11, 2008

### venky56

hi,
problem:
I have a flat plate of dimensions 2.6*2.2, above which a 4mm sheet of water is there(stagnant). Now i will lift the plate on one side, with certain rate till i reach the plate inclination some 10 deg.

Physics:
when i start lifting the plate on one side, water starts flowing to other side.

question:
how much time it takes for the water to completly drain out from plate.

Plz provide me the complete solution taking as many factors into consideration as possible

2. Nov 11, 2008

### tiny-tim

Welcome to PF!

Hi venky56! Welcome to PF!

Show us what you've tried, and where you're stuck, and then we'll know how to help.

3. Nov 13, 2008

### venky56

i calculated in two ways
1) i have taken it as flow over inclined plate and calculated the velocity at bottom end using bernoullis equation. v=sqrt(2gh). and then mass flow rate. since i knew the intial total mass of water, i calculated the time for the water to drain out.
2) here i considered vicosity effect of water also. Vavg=2g*rho*h*h*cos(x)/3mu ........

i dont know if my approach is correct. but as per my calculation, first case is giving more drain out time than the second ase, which is not correct acc to physics.... plz make me clear

4. Nov 13, 2008

### tiny-tim

Hi venky56!

(have a rho: ρ and a mu: µ )
(I suspect you've just got a minus sign in the wrong place, but …)

We can't see where the mistake is unless you show us your full calculations.