Rate of flow from a leak in a storage tank

AI Thread Summary
The discussion focuses on calculating the speed of water exiting a leak in a storage tank and determining the diameter of the hole. The speed is derived using the equation that relates pressure, density, and height, leading to the formula V2^2 = 2g(h(total) - h(from bottom to leak)). For the diameter, the flow rate equation is used, where flow rate equals area times velocity, with the area represented as A = πd^2/4 for a circular hole. The shape of the hole is acknowledged as potentially relevant, but the circular area formula is applied for calculations. The thread concludes with a clarification on using the correct area formula for determining the diameter.
mirandasatterley
Messages
61
Reaction score
0
"A large storage tank, open at the top and filled with water, develops a small hole in its side at a point 16.0m below the water level. If the rate of flow from the leak is 2.50x10^-3 m^3/min, determine; A) The speed at which the water leaves the hole and (B) The diameter of the hole.

So I used the equation;
P(air) + 1/2 d(density)v1^2 + pgh(total height of water) = P(air) + 1/2dv2^2 + pgh(from the bottom of the container to the leak)

The equation then simplifies to:
gh(total height) = 1/2V2^2 + gh(from bottom to leak)
V2^2 = 2g(h(total) - h(form bottom to leak))
V2^2 = 2g(h(from leak to top of water))

Since this h is known, I can solve for v.

I Just can't figure out the diameter part.

Any help is appreciated.
 
Physics news on Phys.org
You're given the volume flow rate (discharge or flux), Q.
 
Last edited:
okay so the equation is;
flow rate = A(flow area)V1

And I can find the area, but how do i find just the diameter.

A= 4/3 pi r^2 (if it were a circular hole)

I'm unsure because it doesn't tell us what shape the hole is. Does the shape even matter?
 
Why 4/3? and yes simply use A = \frac{\pi d^2}{4}
 
Okay, Thanks
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top