Rise Definition and 269 Threads

Hi PF! I have a question regarding the use of centrifugal pumps. I have a system with a constant flowrate of water at 2m^3/s pumping water from a lower to a higher reservoir. The inlet condition is a head of 10m. The Height of the upper reservoir will vary from 83m in the beginning to 287m...

Hi, I have taken some math classes recently, but I feel that they opened some new questions. I am specifically unclear about complex numbers. I have understood how they can be added, divided, multiplied and subtracted algebraically, and then represented on the Argand diagram (is this the same...

Homework Statement (This is not a homework problem; it comes from a real-world problem I'm trying to solve.) Sunlight is falling on an absorptive object. What will be equilibrium temperature of the object given the solar irradiance (I) and the ambient temperature? I = solar irradiance =...

Is the field of the theorized Higgs particle totally distinct from those fields which give rise to fleeting virtual particles? Would the latter also have some kind of 'drag' effect on elementary particles like the Higgs is thought to do? IH

http://www.nature.com/nature/journal/v473/n7346/full/nj7346-243a.html Hmm, what percent of these jobs will be in the private sector, and what percent in the public sector? I'd be concerned about anything in the public sector since the Republicans can easily take it away when they win control...

If you released a balloon filled with helium, how high would it go if it never burst from the pressure change?

Dear All I'm stuck on something that seems to be contradictory. I was under the impression that the further the 2 closed loop poles are in a 2nd order system to the left of the root locus, the higher the damping. Surely high damping means longer rise time? But other sources say that the...

Homework Statement A simple open U-tube contains mercury. When 12.3 cm of water is poured into the right arm of the tube, how high above its initial level does the mercury rise in the left arm? Homework Equations density of water=1000kg/m^3 density of mercury=13534 kg/m^3 The...

what will happen to capillary rise effect if we take capillary to space g=0?

I hope this isn't a half-baked question but it's in regard to recent news stories about massive rises in birth defects in the Iraqi city of Fallujah since the US assault in 2004, for example http://www.guardian.co.uk/world/2009/nov/13/falluja-cancer-children-birth-defects and the possibility of...

I know there have been some forums here about hot air rising, but I'm curious - how fast does hot air rise? Also, how fast does it disperse? If we consider steam, for example, rising and dispersing horizontally from a boiling pot of water. Does anyone know some (hopefully simple) equations to...

When you release a top with high speed, it rises for an instant. Why is this? I've also seen magnets spinning madly when suspended above superconductors. Are these observations related and is there an explanation for this? Many Thanks, :)

What gave rise to cosmic inflation of the early Universe?

Homework Statement True or false: a two input nor gate is designed to have the same worst case rise and fall times. The best case fall time is smaller than the best case rise time in this gate. Homework Equations - The Attempt at a Solution The second part i get, the best case fall...

Homework Statement By what factor would the rate of a reaction for which the activation energy is 159 kJ be increased by a temperature rise of 10degreesC from 25 to 35degreesC? Homework Equations The Attempt at a Solution

hello :) Homework Statement (Q)A 20 cm long capillary tube is dipped in water.The water rises up to 8 cm . If the entire arrangement is put in a freely falling elevator, the length of water column in the capillary tube will be <a>8 cm <b>6 cm <c>10 cm <d>20 cm Homework Equations...

Homework Statement The rise and fall of water in a harbour is simple harmonic. The depth of water varies between 5.0 m at low tide and 9.0 m at high tide. The time between sucessive low tides is 12 hours. A ship, which requires a minimum depth of 6.0 m approaches the harbour at low tide, how...

I was thinking about the function of a capacitor on a very basic level, and it occurred to me that the capacitor also resembles the high voltage electrostatic generator. There is the std LC circuit but that behaves as an AC signal. A capacitor will not build its charge without some potential...

Hey guys, I have a problem in one of my classes where I need to make an equation of capillary rise in a strip of paper towel. I am given data points and I need to make an equation that fits the points. Can someone please help me through the physics and derivation behind this. I tried doing some...

I think evidence is increasingly suggesting that an explosion of sugar, HFCS and refined carb consumption has led to the huge increase in incidence of cancer in the past few decades.

Will there be any difference in capillary rise if the capillary tube is sealed at one end? What is the value of pressure at a point in the capillary tube on the same horizontal level as that of liquid outside? - Is it equal to the atmospheric pressure + the height of liquid column above it?

Is this a good or bad thing? http://abcnews.go.com/GMA/Parenting/unschooling-homeschooling-book-tests-classes/story?id=10410867 https://www.youtube.com/watch?v=XEUzsooa1JE

Homework Statement An aluminum boat is floating in a swimming pool. A hole opens up in the bottom of the boat, and it sinks to the bottom of the pool. Does the water level rise, fall, or stay the same?Homework Equations (Is the buoyancy equation applicable here?)The Attempt at a Solution...

Homework Statement Calculate the rise time (the time require for the output to go from 10% to 90% of its final, or steady state, value) for the circuit shown above when a step input of 5V is applied for the following resistor values: 1k, 10k, 100k, 1000k with C equal to 0.01uF...

Why do we take slope=rise/run (or y/x)? Is it just a definition, or does it have a special significance? Why can't we take slope as run/rise (i.e. x/y)?

I am interested in calculating the temperature rise of a 10 mil aluminum bond wire. Assuming relative purity of the wire, I feel like I should be able to use the method I have worked out below. If anyone can advise on the accuracy of my method, it would be greatly appreciated. Method: 1...

Homework Statement A manometer using oil (density 0.91 g/cm3) as a fluid is connected to an air tank. Suddenly the pressure in the tank increases by 0.72 cm of Hg. (a) By how much does the fluid level rise in the side of the manometer that is open to the atmosphere? (b) What would your...

U-shaped tube-- how far does the mercury rise when water is poured into one side? Homework Statement A U-shaped tube containing mercury is open to the air on both ends. Water is poured into one arm until the water column is 15.0 cm deep. How far upward from the initial position does the...

In Cadence we built a CMOS inverter. I made a transient response graph showing the input and output voltage waveforms. We're supposed to measure rise delay and fall delay of the output voltage. How do I do this? I heard from someone else that it's where the graphs cross 1.5V, but I'm still...

Homework Statement Consider a frictionless track. Imagine point A to B is one quarter of a circle; point B to C is a horizontal flat plane; point C to D is also one quarter of a circle. The block m1 is released from A. It makes a head-on elastic collision at B with m2 (that is initially...

The post "Temperature rise in power transformers was locked, however there may be a simple safe answer. The post said the winding temperature was 73 deg C. 73 deg C is safe for winding temperature. If it was winding temperature RISE of 73 deg C, then there may be problems. So which was it?

The following transformer gets overheated and I was looking for most probable the causes associated with it. 1. Rating : 7.5 MVA, 0.85 power factor, Power Transformer (Manufacturer - Kirloskar) 2. Connected Load : Upto 6 MW 3. Oil Natural Cooling System 4. Normal Atmospheric Temperature ...

In the energy producing region of the sun there is a large radial flux of high energy photons. Does this outward flux polarize the plasma and give rise to a electric field in this inner region? What is an order of magnitude estimate of this field? As the sun rotates this field gives rise to a...

This is actually related to Thermodynamics but as it comes directly under the Mechanical field I'm asking it here and I invite all my fellow Mechanical Engineers and Physics Experts to answer this. The question is : How does the Tempreature of a gas change (increase) when the gas is...

Homework Statement Wind (dry air, so R=287 Jkg^-1K^-1) is moving isobarically along a flat surface at 30m/s. It hits a forest and 3/4 of its kinetic energy is transformed into heat energy by friction. What is the maximum temperature increase that could occur? Homework Equations...

Homework Statement A tennis ball is shot vertically upward in an evacuated chamber(neglect air resistance) with an initial speed of 20m/s at time t=0s. How high does the ball rise? A)98.0m B)72.4m C)20.4m D)10.2m E)40.8m Approximately how long does it take the tennis ball to...

I noticed a couple of similar threads, but I thought it might be better to start a new one for clarity. Imagine a simple DC circuit with a static (time invariant) source of potential and a closed circuit with a simple conductor. If you were to trace the potential from the negative terminal...

Can someone give me a formula or give an approximate approach to calculating the time it would take for an object to be raised up (due to buoyancy) from a certain depth of water? For instance, take a ship (say it weighs 300,000kg and it's a rectangular shape with surface area of 100m square...

I have recently read a few articles by physicist Victor Stenger and about his book The Comprehensible Cosmos: Where Do the Laws of Physics Come From? and it seems he has a fascinating answer to the ancient question of "Why is there something rather than nothing?". Since I am not a scientist I'd...

Hi all, :smile: Technology has advanced phenomenally in the past few decades or so. A particular point of concern…….yeah that’s right!, ‘concern’ is the massive advent in Artificial Intelligence (AI) technology. Softwares so powerful that it will decide the fate of mankind! Maybe, the...

OK, I am attempting to calculate the reuirements for creating a 3-ton, 90-day air conditioner using nothing but ice and an exchange loop between that ice and a heat exchanger in my house. I can calculate everything except knowing how much I can practically insulate a storage vessel, and, given...

Tent cities are springing up. https://www.youtube.com/watch?v=CnnOOo6tRs8 Also http://www.knx1070.com/-Tent-City--Rapidly-Growing-in-Sacramento/3975097 This is reminscent of the Shanty Towns that emerged during the great depression...

My Physics teacher gave us a quiz problem and I don't understand it really how he got his answer. Can you please give me your answer and an explanation for the answer Thanks. Here is the question: A .5 kg rock is dropped from a height of 20 meters into a pail containing .6 kg of water. The...

My Physics teacher gave us a quiz problem and I don't understand it really how he got his answer. Can you please give me your answer and an explanation for the answer Thanks. Here is the question: A .5 kg rock is dropped from a height of 20 meters into a pail containing .6 kg of water. The...

Homework Statement JayJay is running topspeed of 8 meters/seconds, he grabs a string handing vetical fr. a tall-tree. how high will he swings upwards,b.does the length of the string affect the total height?c. if it tkaes him 2s to reach that height, how long is the string.d.explain why the...

Obviously we all know the sun generally rises in the east and sets in the west. But due to axial tilt, it is only really due east and due west at the equinoxes. At other times of the year, the sunrise will be somewhat north of east or south of east (and likewise for the sunset, but let's focus...

I was wondering if there is any solid scientific explanation for the very recent temperature rise in the western-coast of the United States. I live in Arizona, and it's been over 75 degrees for the past week or so. Is this a complete meteorological anomaly? Or does science have some sort of...

There is a new paper about it, the results of the measurements of the GRACE satellites on the sea level changes. http://sciences.blogs.liberation.fr/home/files/Cazenave_et_al_GPC_2008.pdf Good news.

Dunno whether this is the right place for this question! but As it is related to subatomic particles, I think it is! We know that magnetism arises due to rotation of an electron around its own axis in metals, but after all what happens due the moving electric current? Will the same...

i have been searching for something i am positively sure about but I've been told that i am wrong, i couldn't find anything on the internet...so i thought this to be the best way to find some answers to my question... is it true that sound ...also rises up like heat...? pleas answer...