Drop Definition and 876 Threads

hello all... Please can i know physically why the pressure drop in a fluid when there's shear stress? what happens? thank you

I am calculating various pressure drops in a pipe and am and am having trouble calculating the pressure at a certain point, for a set case. This is the pipe... http://i50.tinypic.com/141mikg.jpg A and B are vents, through which air passes and travels on up the pipe, where is it discharged to...

Poles Formula (see page 10 of attachment) www.mech.hku.hk/bse/MEBS6000/mebs6000_1011_04_steam.pdf Where have I gone wrong? • q = flow (m3/h) • d = diameter of pipe (mm) • h = pressure drop (mbar) • l = length of pipe (m) • s = specific gravity of gas (density of gas / density...

Homework Statement The light bulb is 60 watts at 230 volts, how much does the voltage need to drop for the lightbulb to be 40 watts'?Homework Equations V=IA, P=IV, P=IR^2, V=IR The Attempt at a Solution I tried 60w/230v=0,26A... 40w=0,26A*XV<->x=154V so voltage drop is 230-154=76.. I know...

Can anyone explain point 44 of the attached pdf document on surface tension. (Here's the link in case attachment doesn't work: http://www.sakshieducation.com/EAMCET/QR/Physics/Jr%20Phy/12Surface%20tension%20_198-208_.pdf) How is the surface tension direction found out? Also why is...

The basic idea is to package an egg so that it will not break when I drop it off a roof (assume 10m tall). The packaging should be as small and lightweight as possible. I know using a fluid will be rather heavy, but I'm still curious about his. How would I determine the optimal fluid to use? I...

I have a pipe that needs to be 5 degrees below the external temperature outside(eg- 45 degrees outside means 40 degrees within). I cannot remove the pipe or anything, all I can change is the what the pipe passes through, for example if it passes a block of ice then technically the pipe would...

I wanted to know the function of a pressure regulator.. Am using one to control liquid flow rate. Here is my understanding- A pressure regulator can be connected across a valve. The pressure regulator maintains a constant "pressure drop" across the valve so if i set it to give a drop...

Homework Statement A 1.50 x 10^-14 kg oil drop accelerates downward at a rate of 1.80 m/s^2 when placed between two horizontal plates that are 9.40 ch apart. The potential difference between the two plates is 980 V. Determine the magnitude of the charge on the oil drop. m = 1.50 x 10^-14 kg...

Hello... I can't find the difference between the pressure drop in a pipe due to frictionnal loss and the Pressure difference that cause the flow like in Poiseuille Flow.. Thanks

why do the temperature drop if we take down the pressure? If you have a column with mehane, ethane and butane in a gas liquid phase(at 100 bars),why do the temperature drop if we lower the pressure?

Homework Statement Capacitor, C1, is initially charged so that it has a potential difference of 12V. At time t=0, switch S1 is closed allowing the capacitor to discharge through resistor R1. At t=5, the potential across the capacitor has fallen to 6V. At what time will the potential across the...

Homework Statement I need to know how much the temperature drops after an inline heater which heats an airflow of 5 lbs/min up to 88 °C with an pressure of 54 PSI. When the air exits the heater it is released into the free air where it is 20 °C. I know that the air will expand to a...

Hey. I've never formally taken a physics class but when I read the blurb on Brian Greene's The Fabric of the Cosmos it intrigued me and I bought it. I started reading it the other day and there's one particular idea that I'm confused by, and which I hope you all could clarify. Greene...

Hey, Currently I have a system where I have a high pressure at the lowest point of a vertical pipe and a low pressure at the highest point of the pipe. I want the flow to travel down the pipe vertically under gravity but I am unsure of how gravitational head works in the mechanical energy...

Ok, let's say you have a 100v voltage supply and two 50 Ohm resistors in a series circuit. The total resistance is 100 Ohms, leading to a current of 1 amp. Now my question is, what exactly is voltage drop? I know the voltage drop across each resistor is 50 volts. If we were to look at one of...

Homework Statement http://imageshack.us/a/img197/3519/circuith.png Equivalent Resistance of circuit = 17.31 Ω Homework Equations V = I * R The Attempt at a Solution Total voltage of the circuit, if I'm doing this correctly should be: E = (3.00 A) * (17.31 Ω) = 51.93 V...

Homework Statement I did the lab and have to analyze the data to determine the quantized charge of an electron. I have used the data to determine the 'total' charge on the observed drops using the following equation.Homework Equations q = 3 ∏ r (E) η (Vup+Vdown) Where r is the known radius of...

I have a big exam on Wednesday. It's the last one before the drop date. I just need all of the help I can get. Any help would be appreciated. Here is where I am right now: I want at least a B on this test. Made very bad grades on first two tests. However, if I get good marks on last two...

Hello, I am currently assigned to perform a drop tests on a unit that we sell. Thing is that I am an Electronic Engineer so I am not best at mechanics. I am wondering whether you can calculate forces and required material strength to withstand the drop test. The reason I am asking is...

The project requires me to build an Egg-Drop Vehicle that is ranked based on volume*mass (So ligher/smaller is better). And, of course, the egg can't break when dropped from 20 meters. critique my design please: http://img138.imageshack.us/img138/8872/eggdrop2.jpg Any suggestions or...

Millikan Oil Drop Experiment -- A few questions Homework Statement I'm currently doing the millikan oil drop lab; we're using a PASCO Scientific Model 300a (fairly ancient). Specifically, my partner and I are having major problems making any of the droplets in the viewing chamber go back up...

How do i relate pressure drop with "h"? http://www.2shared.com/document/L4fH2kdT/HES_2340_Assignment_1.html Homework Statement Hi, Regarding to the link above, I have a question on my homework on Q2 and Q4. In Q4, What pressure shall i consider in this situation? Shall i include the...

Hello, I'm struggling with the following problem. We have a dryer in our plant which evaporates acetone and with a blower the vapour is driven to a scrubber. However the efficiency of the scrubber is not sufficient and that is why I want to place a plate heat exchanger in the vapour line to...

I am a sophomore math and physics major who would like to go to study biological physics as a graduate student. My aim is not to go into the medical field, i.e. Hospitals, pediatricians etc. but my interest generally is to research ways to prolong the human lifespan. Lately I have been thinking...

Hello, everyone, I am doing an egg drop for my science class, (not sure where to put it so I put it here, sorry if it's the wrong place.) and I have developed a few designs. I would like to know which you think would be most successful. (Dropped from gym class bleachers.) Parameters: Must...

Having a little trouble with this latest advanced egg drop assignment. The main assignment has two parts - 1. Create a rocket that can reach a minimum height of 120 ft 2. Create a vehicle that can land with an egg for a passenger, and not have it crack. We also aren't allowed to use...

I've posted a thread awhile back about whether my work load for this semester is manageable. The courses I enrolled in were: QM II Nuclear and Particle Physics Mathematical Methods of Physics PDE Abstract Algebra After some serious consideration, I have decided to drop one of the...

Homework Statement Suppose I drop a ball from high enough in the sky that, at some point, it reaches terminal velocity. At this point, the ball is no longer accelerating. It is traveling at a constant velocity. Does this mean that at terminal velocity, the force of gravity on the ball is...

My chemistry teacher recently explained the Millikan oil drop experiment to us. However, he rushes his lectures to the point where it is almost impossible to ask him questions. What I was wondering in regards to this experiment is why is the positive plate used in the experiment? I...

Hi Folks; As we all knew, and I used to experimentally observe it, as the temperature of water increases, pressure drop through pipeline (kPa/m) decreases. Now, I am getting the opposite, while the results are so consistent and reproducible ! As the water temperature increases, pressure drop...

Hi folks, my prof gave us some problems calculating pressure drop in two phase flow. She did some examples and somehow she got the density of water-liquid and water-vapor from steam tables, but she did not explain how. I have never used these. I am especially stumped on the density of...

I'm given a strange single-diode circuit where you must find out whether or not the diode is on. See the top diagram in the linked image: http://i.imgur.com/y1sn3.png (Current source is indeed 1 Amp, not 1mA as the 2kΩ resistor would suggest. Please do not try to correct the initial question...

First, this is just something I've wondered for fun...not serious, and just wonder if if the laws of physics make this possible. Would it be possible to create a drop pod shape such that a person could be dropped from a helicopter from a high altitude and have it hit the water (ocean) such...

hi guys OK, this has annoyed me for some time. I like my cups of noodles. The pack of noodles and sachet of flavour powder (obviously dry) go into the cup with hot water poured on them. Now if I fill the cup to the brim with the hot water, it will start to lower in level over a period of...

I am contemplating dropping out of school right now and taking a year off doing work. Then coming back to a school later, hopefully a less expensive one, where I can take classes only focused on the subjects I want to do in science. My interests are math and physics as well as biology and...

In the bean machine, we usually drop the balls from the center of the top right? That's the reason why most of the balls accumulate in the middle bin. If you drop the balls from the top right corner (say) then balls should fall in the bins in the right side, right? Thanks a lot.

I am doing a simple steel ball drop test on glass to see if the glass passes the standards. We are dropping 1.18 inches (0.535kg) steel ball at the height of 51inches (1.295m). Now, I can calculate final velocity at the impact, but cannot calculate the actual impact force. One of the method...

I completed the Millikan oil drop lab in class with as much accuracy as possible. I used the PASCO interface and used a very accurate Air pressure calibration. My final experimental charge of the electron derived from the equation in the lab was, 1.8 x 10 ^-19 C. When I turned in my lab, I was...

Hey guys, I am new here so I figured I would post a problem I am having and see what comes out. I am designing a circuit that will force a voltage across a proprietary load that I cannot divulge on, but for this example we will assume it's resistors. So far everything works great but I am still...

Homework Statement Estimate the pressure drop in a tower packed with porous support. This tower is an integral part of a water oxygenation system and will need to operate over extended periods without cleaning. From the following data estimate the pressure drop you expect to see on...

Hi Guys, I have a model gas turbine that is driven by an ecu ... the ecu starter output is 12.6volts but the starter motor is rated to 6volts. The ECU can easily supply 20amps although the starter motor is rated to 5amps max efficiency. I need to drop the voltage from 12.6volts to...

1. An electrically charged macroscopic spherical oil drop of mass M=5.449x10^(-14) kg is released from rest between two electrically charged horizontal plates that produce a uniform electric field magnitude of E=1.667x10^6 N/C that is directed vertically upward. If, after release, the oil drop...

Hey all, I'd need help with determining the pressure loss over an orifice in a pipe. I have an equation for the friction factor so no problem there, and I know the Reynold's number as well. What confuses me is choosing the suitable velocity for the pressure drop equation; \frac{Δp}{ΔL} =...

Dear Experts I just connect a diode to a battery rated at 4.2 volts. The diode takes about 0.8volts ( i thought should be 0.7v but measurement says 0.8v) and the battery is currently at 3.12v. The supply voltage is 5v dc. After some time, if the battery reaches 4.2v, would current...

Universe is expanding but is it due to drop in gravitational forces all over in the universe ? Gravitational force holds all the objects together in the universe ...? Universe is expanding means one object is moving away from another, Is this due to drop in Gravitational force ? If Yes...

Let initial preasure (P) = 10 bar,volume of container (V)=100000 cubic cm. At what time period pressure will become 5 bar.

Electrical question: I live in Mexico ( retired ex-pat ) and my electrical supply ( 240 volt single phase ) comes through a transformer that is almost 1 km away from my house. The supply lines are 2-0 aluminum. Because of the distance and from usage by others on the line, the voltage is...

I must have been asleep in physics when we did torque (well it was a while ago, before I discovered beer) and am re-visiting the subject afresh. I am trying to choose a motor to lift a pop-hole door to a hen house. The motors I'm looking at have a torque rating from 400 to 1000 gf.cm, which I...

So here is the problem I have. There is a box that is 27.5" tall and 41" tall with a mass of 480lbs. One edge is put on a 3.5" tall block while the other is raised 12" and dropped. The question is to see if the block will continue to rotate and fall on it's side. I have been able to find the...