Drop Definition and 876 Threads

Hey I've gotten some good answers here before, so I'm giving it another try: Recently I attended a building-engineering meeting, and trying to learn something new (or refresh old knowledge in some cases..) I had a hydrodynamic question/case. My firm is engineering a concrete tank for a water...

Homework Statement In Fig. 26-5, how large must R be if the potential drop from A to B is 12 V? (The figure has been pasted into the attached file). The answer to this problem is 3.0 ohms. I keep trying to solve this problem but I get a wrong answer. The answer I get from my calculations does...

Something that routinely comes up as a problem at work is when we size flow projects for piping systems. We calculate pressure drop across a length of fixed diameter for compressible gasses, but we do not calculate pressure changes through an expansion or contraction with gas (for example...

Hi guys, I know the difference between these two things but I'm struggling with something that I hope someone could help me with. What dictates the water pressure needed for a "system" to work? I would imagine that if you've calculated your system to have a pressure drop of 1 bar (for...

1. Homework Statement Homework EquationsThe Attempt at a Solution [/B] I know that if white light is incident on a triangular prism , then lights of different wavelengths are deviated by different amounts and dispersion occurs . But I am not sure what would happen in this case where we have a...

Hello, I am calculating pressure drop through a pipe using CFD, which will be validated with hand calculations and experiments for a project. When I take results from my software, I can either take the pressure at a specific point (assume the centreline of the pipe) or I can take an average...

I am a non technical innovator trying to develop a new product. Can someone help me calculate pressure drop and flowrate across a cylinder packed with uniform spheres of 10mm diameter. I found this online but unable to calculate...

OK, first of all, I am not quite certain where this topic should go. It does deal with academic guidelines and requirements, but it isn't really a "guidance" for students. So I was half tempted to post this in the General Discussion forum, but at the last minute, decided to post it in Academic...

some may not have seen this video done in a vacuum chamber enjoy

I've been reading some speculative articles about the possible quantum arrow of time which emerges through collapse and irreversibility. My question is: does collapse in the Copenhagen interpretation (or perhaps in a objective-collapse model) allow the spontaneous decrease of entropy where an...

Voltdrop calculations are made as shown below. Total loadLine currentI=1.5/−60∘⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯+2.3/−18∘⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ =(0.75−j1.3)+(2.19−j0.71) <<< (How to get to these numbers only from above??) =(2.94−j2.01 )=3.56/−34.4∘⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯MVA

Homework Statement A stone is dropped into some water and a circle of radius r is formed and slowly expands. The perimeter of the circle is increasing at 3 m/s. At the moment the radius is exactly 2m, what rate is the radius of the circle increasing? Answer ## \frac {dr} {dt} = 0.48 m/s##...

Homework Statement Determine the voltage drop and current through each resistor. *This is just my sketch of the problem since I couldn't take a clear picture of it. Homework Equations Ohm's law V= IR Parallel total resistance Req=1/R1+1/R2+1/R3+... Series total resistance Req=R1+R2+R3+...

I have a pump running at 400rpm with 8" inlet and outlet with head 30 ft 500 gpm. Now I am planning to reduce the discharge line to 6" . Assuming the flow rate and speed constant the velocity in the pipe will increase. How do I calculate the change in head?

How is it that once the dew point is reached, moisture continues to condense. What is causing the imbalance of partial water vapor pressure? Does the rise in atmospheric temperature simply pass up the evaporation rate too quickly?

Not a question but such a good clip for those that have not had the pleasure;

I'm an engineering student, one of my task is to search the best orifice type for pressure drop. I have no idea which one would it be since I believe that the beta ratio is the one that would determine the best orifice for pressure drop.

Homework Statement Hi, Iv got to find the minimum diameter of a pipe if the pressure drops in a system is to be limited to 0.3bar. when delivered through a pipe of equivalent length 160m I have to use the formula Pressure Drop = 800lQ^2/Rd^5.31 I believe I have to transpose this to find...

So, a coworker approached me today with a 'simple problem' to solve, looking to sanity-check a design choice. Much to my dismay, I had no idea how to approach it. Worse, google had no straight-forward answers either, and any formulae I did find seemed circular. This seems too simple to...

I'm trying to optimize a system involving one or more propellers / fans driving air through a packed bed for scrubbing (compressed then expanded) and out the other side to achieve propulsive thrust. So there's going to be a pressure drop in the slipstream. I've already set up a system to do the...

Hey PF, first time here, I have a problem I can't seem to solve! Any help is appreciated. I am using some DC motors with peristaltic pump heads to pump water (picture). I was having issues so I've broken my circuit down to the bare basics: 1) 12V regulated power supply 2) 12V motor 3)...

Where does the voltage drop of a capacitor happen? My answer would be that It produces an electric field the opposes the field of the battery along the wires. So it is continuous lose to the capacitor which stores this energy in it. Another question related to this, When a positive charge hits...

Hi all, I'm having a Kaiser compressor producing compressed air for my garage. I've installed a FRL unit at point of use. I understand that the filter medium adsorbs atmospheric dust, moisture and oil particles in compressed air. Gradually the pressure drop across the filter builds up and I need...

Homework Statement [/B] Q = A / V Bernollis therom → γH = P+γZ+ρ.v2 /2 Air Flow Speed = 0.058 m3/s A = Section Area of the tube = π.r2 r = 19.65 mm ρ =1000 kg/m3 g =9.8 m/s2 P=pressure energy of water = 2.338 Homework Equations Find : V= Fluid Velocity = ? H=Energy Denisty = ? Z= Geodesic...

For my physics assignment we have to design and test a way to allow an egg to fall from a three storey building and not crack. The only requirments are the egg must be visible in atleast one place and the smallest design wins. I tried making a crumple area and then protecting the egg with...

Millikan Oil drop experiment. For my current lab, we are recreating the milian oil drop experiment to measure the charge of an electron. However, we are using 1-micron diameter latex spheres in place of oil drops. Problem: I am having difficulty deriving an equation for the speed of the drop...

Hi folks, I have a pressure sensor working with arduino to measure depth. I want to calculate what I should see as a change in pressure if I move the tube horizontally under the surface of the water, keeping the tube opening parallel to the flow. I have calculated the dynamic pressure but...

1. Homework Statement The problem is above, I am having a hard time figuring out why the right answer for part F is "greater than." Homework Equations Ucapacitor = 0.5 * C * V^2 The Attempt at a Solution [/B] My problem is figuring out the logic in how the capacitor's energy would...

In our textbook, it says that the intensity of a double slit interference pattern stays the same if the slit width is negligible. I do not understand this concept. As far as I am concerned, intensity should decrease as the circle of diffraction increase, as intensity is work per area, and the...

Hi. Consider a simple circuit consisting of a voltage source ##U## and a load with resistance ##R##, e.g. a lamp or a motor. The current is given by ##I=U/R##. The number of electrons passing the circuit per second is ##n=I/e##. The power consumed by the load is calculated by $$P=U\cdot...

Homework Statement In a measurement of the electron charge by Millikan's method, a potential difference of 1.5 kV can be applied between horizontal parallel metal plates 12 mm apart. With the field switched off, a drop of oil of mass 10-14 kg is observed to fall with constant velocity 400 μm...

Homework Statement Suppose you want to run some apparatus that is 95 m from an electric outlet. Each of the wires connecting your apparatus to the 120 V source has a resistance per unit length of 0.0065 Ω/m. If your apparatus draws 2.9 A, what will be the voltage drop across the connecting...

Hello, The particle Reynolds number makes me confused and I hope someone can help me on this please! Normally (as I read in every books and papers) that when a bubble or drop rises in a fluid, the bubble/drop Reynolds number is calculated by: Re = ρUD/μ where U is particle velocity, D can...

Hey everyone can anyone tell me how much energy is released (joules) if you take 1 liter of water at 100C and drop it down to 25C (room temp, reg pressure)? Is it significant amount? Better even how much energy is released (approximately) for every 1c drop in temp? Is the release in energy...

Howdy y'all! If you could help with the following question, my physics class and I would be extremely grateful. A charged oil droplet is suspended motionless between two parallel plates (d=0.01m) that are held at a potential difference V. Periodically, the charge on the droplet changes as in...

Hi. I learned that in an ideal conductor in a circuit, the voltage drop is zero. But how does this agree with the basic definition of voltage $$U_{AB}=\int_A^B \vec{E}\cdot d\vec{s}\enspace ?$$ The electric field inside a conductor only vanishes in static conditions, but in an electric circuit...

Homework Statement Homework Equations Projectile motion. Vy = 0 Vx = V0The Attempt at a Solution I integrate Vx to find d in terms of t I found d = V0*√(2h/g) Correct?

Good evening everyone, I have a pressure meter from where we determined a pressure drop of 5.5 psi (Initial pressure 45.5 psi, final pressure 40 psi). The working fluid is air. The diameter of one of the hoses that is connected to the pressure meter is 1/4". I wasn't able to take a picture of...

Hi I'd like to ask how you would put a droplet at high viscosity (say 2.5 million times more viscous than water) on a solid surface? The droplet would have to be small (volume less than 10uL, r<1.34mm).. Thanks!

Hi I'm trying to solve a problem but I'm a bit confused about this part: Suppose you are walking at a speed of 2 m/s when you drop the ball that you were holding in your hands. Is the initial velocity 0 m/s? In the textbook it says that initial velocity for dropped objects is 0 m/s but that...

Homework Statement The pressure in a bulb dropped from 2000 to 1500 mm of mercury in 50 minutes when the contained oxygen leaked through a small hole. The bulb was then evacuated. A mixture of oxygen and another gas of molecular weight 72 in the molar ratio of 1 : 1 at a total pressure of 6000...

Would it be a drop in power as the square of the distance in a directed microwave beam? Thanks!

In CE amplifiers with negative feedback I can't understand what it means that the emitter becomes more positive (when hfe increases and VE increases with it). Does it mean that there is less negative charge after the emitter resistor (going from ground to Vcc) and the emitter feels some positive...

https://puu.sh/qzv6o/5abc45494b.png I was under the impression that voltage drop was the same in parallel which would make it the power supply, but apparently not? Any insight would help. I know this isn't a hard a question, I'm just horrible at physics.

why does the pressure drop equation derived for the laminar flow has no parameter to indicate the surface roughness of the material of the pipe,unlike the turbulent flow !

Hi guys, I am performing drop-weight impact tests on concrete slab. I have designed a bullet made of high tensile steel and I am interested to recorded the acceleration, then convert it to impact force. For this purpose, I need to implement an accelerometer on the bullet. I have tried two...

I want to make something clear. Most diodes have in their datasheet some current for a given treshold voltage. For example a led will pass 20mA current when 4volts are applied to it. Or a zener diode's minimum turn on current is 10mA when 5,6 volts are applied across it. Does this mean this...

I've modeled a U-Pipe with laminar flow. The pressure drop from Fluent is about 3 kpa , but by theory it should be about 6 kpa (checked several times and I'm sure) My mesh is very fine and boundary conditions are vel-inlet and pre-outlet and wall. Would you please help me with the problem?

Hi everyone Would like some help here. If I draw a control volume across a valve that I can control the flow area to, and I know the temperature and pressure upstream of the valve, I will know its enthalpy:in. High temperature liquid going through this valve supposedly changes to steam due...

for my own intressest i thought of a way to look i a potato could survive a 100 metre drop. my hypothesis was abviously no not it will be potato salad when it hits the ground. but my calculations turned against me as far as i know. here are they average potato weight: 0,15 kg height: 100m i...