Pascal's principle/pressure/viscosity

  • Thread starter Thread starter ally1h
  • Start date Start date
AI Thread Summary
The discussion revolves around a homework problem involving a large storage tank filled with water, requiring calculations based on Pascal's principle, pressure, and viscosity. Key tasks include determining atmospheric pressure, calculating the flow rate from a smaller pipe, estimating the time to empty the tank, and finding water velocity and pressure at different points. The original poster expresses confusion about starting the problem, particularly with the atmospheric pressure calculation, which they found to yield an incorrect result of exactly 1 atm. The thread highlights the challenges of applying fluid dynamics principles to practical scenarios. Assistance is requested to navigate the problem effectively.
ally1h
Messages
61
Reaction score
0

Homework Statement


A large storage tank (diameter 10m) is filled 10m deep with water (density= 1000 kg/m^3, viscosity= 1.0x10^-3 Pa*s). The outlet at the bottom consists of 2 pipes, as shown. The large pipe has a diameter d2= 0.1m, and the smaller have a diameter d3= 0.05m and length of 20m. A pressure and flow gauge at point A indicates an absolute pressure of 1.95x10^5 Pa, and a velocity of 6 m/s for the water inside the large pipe. You may assume points A,B, and C are all at the same height, and that the height is 0.5m above the bottom of the tank.

Link below takes you to the diagram...
http://farm4.static.flickr.com/3073/2728597416_16e9339014.jpg?v=0

a) Determine the atmospheric pressure. (Warning: it will not turn out to be exactly 1 atm.)

b) If the outlet of the small pipe is atmospheric pressure, how many cubic meters of water leave the tank each second?

c) How long will it take to empty the tank? (Assume the outward flw is a constant for this calculation!)

d) Find the water velocity and pressure at point B, inside the smaller pipe.

e) At point C, the storage tank has a square hole, 5cm x 5cm. A little dutch boy is holding a patch in place over the hole. How much force does he have to exert (horizontally) to keep the patch in place? Explain the reasoning.



Homework Equations


Pascal's Principle
101.3 Pa= 1 atm
P = F/A
P = Patm + ρgd



The Attempt at a Solution


Wow... I am baffled as to how I should even start this. Trying to a) brought me to exactly 1 atm so obviously THAT isn't correct. I am at a complete loss...

Please, someone help?
 
Physics news on Phys.org

Thread 'Errors and significant figures'

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...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

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...
View full post »

Similar threads

How Does Bernoulli's Principle Apply to Fluid Flow in Pipes?
Replies
1
Views
3K
Bernoulli's Equation and A Water Tank w/ Small Outlet
Replies
2
Views
12K
Viscosity finding the velocity at a point
Replies
1
Views
2K
Finding speed of water leaving a pressurized vessel
Replies
1
Views
9K
Water flows from a compressed tank
Replies
2
Views
1K
Water Pressure in Pipe: 85L/s at 35m Depth
Replies
18
Views
4K
Understanding Pressure Drop Calculations in Fluid Mechanics
Replies
6
Views
11K
How Does Bernoulli's Principle Apply to Varying Pipe Diameters and Water Flow?
Replies
3
Views
2K
Problem about Hagen-Poiseuille law and pump
Replies
15
Views
5K
Pascal's Principle Homework: Pressure Variation w/ Height & Diameter
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top