Fluids Definition and 482 Threads

Homework Statement I have an empirically-derived equation for the shear stress of a fluid on a surface, given by the equation below. I am supposed to take the derivative of density with respect to distance, and I must use this equation to find an expression for density. Delta = Boundary...

http://img255.imageshack.us/img255/7909/hrw71431.gif http://g.imageshack.us/img255/hrw71431.gif/1/ An open tube of length L = 1.8 m and cross-sectional area A = 4.6 cm^2 is fixed to the top of a cylindrical barrel of diameter D= 1.2m and height H=1.8 m The barrel and the tube are filled with...

Tank A |...| |..h2o...| |..h2o...| |_h2o__| Tank B \.../ .\..h2o../ ..\.h2o./ ...\h2o/ Tank C .../...\ ../.h2o.\ ./..h2o..\ /__h2o__\ The three tanks shown above are filled with water to an equal...

I am working on the problem below that is confusing me. I am not sure of how to approach the center of pressure and resultant force. I attempted the problem using the formulas for a rectangular wall but I am not sure if its right. The problem asks for the pressure acting against the FLAT ends...

Homework Statement A typical mud is compsed of 76 wt% sand and 24 wt% water. What is the density? Homework Equations No relevant equations but density of sand is 951 kg/m^3 and 1 kg/m^3 for water. The Attempt at a Solution Just multiplied the density by the percentage and added...

So it has always been my understanding that in order for something to electrically conductive it has to have more electrons than it needs. If the electrons can be easily shaken from their atoms, then it's conductive. The easier it is for the electron to move to the next atom the more conductive...

Homework Statement A submarine is at a depth of 500 m under the water. The force on a circular hatch of 1.00 m in diameter due to the seawater (density = 1,025 kg/m3) pressure from outside the submarine is: Homework Equations F=PA P2-P1=pgd The Attempt at a Solution F=(pgd+P1)A...

What's wrong with this statement: 'Ideal fluids always flow from high pressure to low pressure'? Could someone give me an example of where this is not true?

Homework Statement [This probably seems really easy to the physics whizzes out there but...*blushes*] Two identical cylindrical vessels with their bases at the same level each contain a liquid of density 1.30x103 kg/m3. The area of each base is 4.00cm2, but in one vessel the liquid height is...

Homework Statement I'll just post the question given: You are at the clinic getting your flu shot. The syringe that is being used to deliver the vaccine has a volume of 2.0 mL, an inner diameter of 6.0 mm, and the needle has an inner diameter of 0.25 mm. The plunger on which the nurse has...

1. A fountain sends a stream of water straight up into the air to a maximum height of 4.23 m. The effective area of the pipe feeding the fountain is 5.38 x 10^-4 m^2. Neglecting air resistance and any viscous effects, determine how many gallons per minute are being used by the fountain. (1 gal =...

I want to write a opengl (graphical) representation of a non-deformable ball or other shape in general being dropped onto a liquid surface. The surface will consist of a grid with surface maps. So I need to calculate I assume the wave equation in response to the object impact. Once I get the...

seeking help..please why do low frequency contributes a low pitch?how?& why only longitudinal in fluids?can any1 please explain to me,tq please..:smile:

Every student knows the flow through a long tube ignoring end effects but my "A" level son has asked if there is a formula for the flow of a fluid through a this hole (or out of a bucket with a hole at the bottom). I think such a formula would include surface tension, viscosity and other...

Fluids -- pressure Blood plasma flows from a bag through a tube into a patient's vein, where the blood pressure is 10 mmHg. The specific gravity of blood plasma at 37°C is 1.03. What is the minimum elevation the bag must have so the plasma flows into the vein? Prof gave this problem for us...

Hey guys, I am studying in heriot watt university Dubai. I would like to be a Fluids expert. I have been doing well in my course-works and my professor usually helps me around to get a few extra info. However recently due to a tight schedule he is unable to help me out. I have managed to...

Hi I am working in an application where we pump a fluid in a water -filled tube, where the second fluid has a viscosity of 3-4 times the viscosity of water. We have laminar flow (Re around 20). If the fluids were 100% compatible (e.g. colored water vs clear water) I have determined that...

Hi, I am trying to do a cross flow analysis in FLUENT. Air and water in a cross flow heat exchanger. The fluids do not come in contact. I have modeled and meshed the geometry in GAMBIT. Could someone pls help me with the steps in FLUENT as to how to assign different fluid properties for...

I'm stumped on a HW question that I just can't seem to proceed on. Homework Statement An incompressible ( rho = constant ) flow in 2 dimensions [x = (x,z)], with F = (0,-g), satisfies Euler's equation. For this flow, the velocity is u = (u0,w(x)), where u0 is a constant, with w = 0 on x...

Homework Statement A boat floating in fresh water displaces water weighing 37.3 kN. What is the difference between the volume of fresh water displaced and the volume of salt water displaced (Vfresh - Vsalt)? F(bu) = 37.3E3 kg/m^3 (rho)fresh water = .998E3 kg/m^3? (rho)salt water =...

Homework Statement Very small particles moving in fluids are known to experience a drag force proportional to speed. Consider a particle of net weight W dropped in a fluid. The particle experiences a drag force, Fd = kV, where V is the particle speed. Determine the time required for the...

Homework Statement In an ideal fluid, the pipe length is doubled, while radius is decreased by factor 2 what will have to the velocity and volume that is flowing? Homework Equations Q=Av = pi*r^2*v The Attempt at a Solution From this the volume that will pass, in ideal fluid cases...

An open tank has a horizontal bottom. It is divided into two parts by a vertical gate. The gate is rectangular, 3m high and it is hinged at its top. Water of density p,=1000kg/m3 in one part of the tank is acting on one side of the gate, and oil of density p, in the other part of the tank is...

Hi - I'm having trouble with the bouyancy force. I understand that in static equilibrium a force from below a submerged object (not resting on the floor of a container but in the liquid) equals the overlying liquid plus the weight of the object. So that the bouyancy force is the difference of...

Okay, so I'm stuck on the last part of the problem : A hydraulic lift has two connected pistons with cross-sectional areas 15 cm2 and 430 cm2. It is filled with oil of density 620 kg/m3. -------------------------------------------------------------------------------- a) What mass must...

Homework Statement Hi, I'm trying to follow the proof for the statement \nabla . u = 0 I'm basing it off this paper: http://delivery.acm.org/10.1145/1190000/1185730/p1-bridson.pdf?key1=1185730&key2=4151929021&coll=GUIDE&dl=GUIDE&CFID=25582973&CFTOKEN=82107744 (page 7, 8) In...

I understand that in an ideal fluid, when the cross-sectional area of the pipe is increased, the pressure that the fluid exerts on the walls of the pipe also increases. Also, when the cross-sectional area of the pipe is decreased, the pressure that the fluid exerts on the walls of the pipe...

[SOLVED] need help with fluids and pressure problem Homework Statement The L-shaped tank shown below is filled with water and is open at the top. (a) If d = 4.0 m, what is the force on face A due to the water? N (up) (b) What is the force on face B due to the water? N (right)...

Homework Statement THe human lungs can operate w a pressure differential of abt 1/20 of an atmosphere. If a diver uses a snorkle for breathing, about how far below the water level can they swim? Homework Equations P=P(i) + pgh where p is ro, density. The Attempt at a Solution...

Homework Statement A simple U-tube that is open on both ends is partially filled with a liquid of density (491 kg/m^3). Water is then poured into one arm of the tube, forming a column height of (8.2 cm). The density of the heavy liquid is (1000 kg/m^3). What's the difference , h, in the...

Hello all, I have a very basic question about fluids. Here it is. There are two containers, one has alcohol in it and the other has oil. A steel ball is held down inside of each. A scale will weigh the steel ball as it is held down in the alcohol and then in the oil. Will the ball be...

1. A man falls into a tank at 40 degrees C. His body temperature is 98.6 degrees Fahrenheit. I want to ask if the man will freeze to death, but I don't know at what temperature that happens. Can I ask them to figure out what his final body temperature is, if say he doesn't get rescued in 10...

Homework Statement An above-ground backyard swimming pool is shaped like a large hockey puck, with a circular bottom and a vertical wall forming its perimeter. The diameter of the pool is 5.2m and its depth is 1.4m. Find the total outward force exerted on the vertical wall of the pool...

Homework Statement Hi guys Please take a look at the second question in 10.20 (the question with the diff. equation)...

1. The time required to fill a bucket with water from a certain garden hose is 30.0 s. If you cover part of the hose's nozzle with your thumb so that the speed of the water leaving the nozzle doubles, how long does it take to fill the bucket? 2. Homework Equations : None required. I hope...

Homework Statement A solid cylinder 350mm in diametre and of total length 750mm floats upright in fresh water to a depth of 500mm determine (a) the mass of the cylinder.(b)the density of the material in the cylinder. Homework Equations mg=pgha The Attempt at a Solution area= lxd...

First, let me introduce myself. I am new to these forums, but not new to sharing ideas that cause argument. If you think anything I say is wrong, please speak up. The reason I joined was because of this outrageous 2+ year old thread: https://www.physicsforums.com/showthread.php?t=70227 The...

[SOLVED] Fluids and Forces Hi, I'm new to this site, so I'm not sure if this is the right place to post. I found a year-old entry with the same question that I'm having trouble with, found here: https://www.physicsforums.com/showthread.php?t=153538" For Part a, I followed the same method...

Homework Statement Using Archimedes' Principle and the diagram shown: (diagram is a "mass" of something in a liquid with an immersed portion (Vb) and an Un-immersed portion (Va)). A. prove that if an object is floating in a liquid, the fraction of the object's total volume that is...

Fluids at rest problem help! Homework Statement How much force does it take to hold 0.5 m^3 of medium density (specific gravity = 0.77) wood under water? The Attempt at a Solution density of wood is 770 kg/m^3. Fb is the force of buoyancy that pushes the wood up. F-Fb = mg...

Hi, I am having some trouble with a couple problems from an AP Physics worksheet. I don't really think that they are actually that hard overall but I'm justhaving a hard time tryng to figure out where to start. Here they are: A 90,000 kg structure is built on stilts on the surface of Saturns...

Homework Statement A cylindrical can of height h and base area A is immersed in water to a depth ho and left to sink down. A small hole of area 'a' exists at the bottom of the base of the can. Determine how quickly the can sinks. http://img80.imageshack.us/my.php?image=fluids1wb7.jpg...

heheh...I need some help understanding something. If there was an object, such as a sphere, in water, gravity would be pushing it downwards, while a resistive force R = -bv would be pushing it upward (b as a constant). that would imply that the net Force Fy would be Fy = mg - bv = ma =...

Homework Statement A small sphere 0.75 times as dense as water is dropped from a height of 11 m above the surface of a smooth lake. Determine the maximum depth to which the sphere will sink. Neglect any energy transferred to the water during impact and sinking. for clarity's sake, I'm...

A cylindrical container 1.2 m tall contains mercury to a certain depth, d. The rest of the cylinder is filled with water. If the pressure at the bottom of the cylinder is 1.9 atm, what is the depth d? Does anyone have any ideas on how to approach this problem, better yet,solve it!?

[SOLVED] i need help with a static fluids question Homework Statement A block of wood of 1.8 kg mass floats on water with 64% of its volume submerged. A lead block is placed on the wood and the wood is then fully submerged. Find the mass of the lead block. Homework Equations Fb =...

Homework Statement Heated air at 1 atmosphere and 35 deg. Celsius is to be transported in a 150 meter long circular plastic duct (smooth) at a rate of 0.35 cubic meters/sec. If the head loss in the pipe is not to exceed 20 meters, determine the minimum diameter of the duct. Homework...

Homework Statement A brick weighs 15.0 N and is resting on the ground. Its dimensions are 0.203 m 0.0890 m 0.0570 m. A number of the bricks are then stacked on top of this one. What is the smallest number of whole bricks (including the one on the ground) that could be used, so that their...

I have solved this problem but am not sure where I'm going wrong here... Suppose you pour water into a container until it reaches a depth of 20cm . Next, you carefully pour in a 9.7cm thickness of olive oil so that it floats on top of the water. What's the pressure at the bottom of the...

Homework Statement In scuba diving, a regulator is used so that the pressure of the air the diver breathes is close to that of the ambient water. A reckless swimmer decides to use a hose sticking out of the surface to breathe underwater while diving in a lake. When the air pressure in the lungs...