Balance Definition and 461 Threads

I collect branded goods and came across this old Energiser battery which had been left at one of those communal recycle collection points in our local supermarket, what a find, it's the old ones that I remember from my childhood and labelled as "Made in Britain" (my God, that must have been some...

Green Plants do Photosynthesis in day during presence of sunlight and intake C02 to produce O2. In night, Plants do respiration and intake 02 to produce C02. If there will be no animal then Green plants will survive ? Because Earth is like ball, Plants will do photosynthesis=respiration...

So for the last 3 years (off and on) I have been designing an engine. I have gotten much more serious lately as it could help me get a job that I seriously want, but somethings have stopped me in my tracks. On of the biggest things is the g.d. crankshaft. It is a pain because it does so much for...

Homework Statement Two forces are acting on an object. The magnitudes of them are F1=10.0N, F2=4.0N. If a third force F3 is applied on the object, what is the smallest magnitude of F3 needed to balance the first two forces? Homework Equations N/A The Attempt at a Solution I've done...

This seems like it would be pretty simple and I apologize if this is in the wrong area, here goes. Picture a flat disc. It is supported by a pin or marble in the center. There are no forces acting on it. Now at 0 deg, I apply a force F (all forces are a distance equal from the center)...

Homework Statement Question 2. Tetraethyl lead was used in early model cars to help reduce engine knocking, boost octane ratings, and help with wear and tear on valveseats within the motor. In Australia, our petrol contained lead between approximately 1950 and 2002. Consider the impact of...

Homework Statement Question 1. An industry uses a long drainage ditch to break down their wastes and in particular to remove the odour. The waste travels along the ditch at a velocity of 0.5 m/h. The odour is reduced as a first order reaction with a reaction constant of k=0.30 day-1 The...

Hello, Im new here, sorry for my english, but I am in desperate need of help regarding my own experiment which i need to finish. I need to calculate steam kg/kg (flash steam maybe in english?). Basically i have entering steam temperature and pressure and exiting steam temp. and pressure from...

Homework Statement The following chemical reaction takes place inside a reactor where 80% conversion is obtained with an equimolar mixture of NH3 and O2 fed at the flow rate of 100 mol/h. 4NH3 + 5O2 ⇔ 4NO + 6H2O What are the output rates of all species? There's a diagram shown where...

Why is it that it's much easier to balance on a moving bike than a stationary one? I've heard a few different answers: 1. The wheels of the bike each have their own angular momentum vectors, which like to stay pointed in the same direction, and hence resist tipping from side to side (sort of...

Homework Statement Ten kmol per hour of air is throttled from upstream conditions of 25°C and 10 bar to a downstream pressure of 1.2 bar. Assume air to be an ideal gas with Cp= (7/2)R. (a)What is the downstream temperature? (b)What is the entropy change of the air in J mol-1K-1? (c)What...

Homework Statement Question: is the charge sum an approximation? Homework Equations E.g. consider 0.10 M Na_{2}SO_{4} solution. Charge sum appears to be 0.20 from elementary stoichiometric considerations. The Attempt at a Solution The charge sum, however, seems to be ignoring...

First of all, let me just say I'm a long way away from being a wife/mom and from even thinking about having a career. I'm still an undergrad. Although I love physics and want to pursue a PhD and eventually begin a career, I guess that being a mother is more important to me. And now that it's...

I have a classroom full of Ohaus cent-o-gram model 311. Most work fine, but a few I can't calibrate to 0. I've used the calibration screw, but even maxed out it isn't enough. I could always place a couple of pennies under the tray, but there's got to be some way to do a course adjustment...

Homework Statement A particle with charge q = 4.00 10-6 C and mass m = 1.30 10-4 kg is moving parallel to the Earth's surface at a speed of 1000 m/s. What minimum strength of magnetic field would be required to balance the gravitational force on the particle? Homework Equations Not...

Homework Statement For 1 M CaCl_{2} what is the correct "charge balance" for all species? Homework Equations Charge balance is an algebraic statement of electroneutrality. The sum of positive charges = sum of negative charges. The Attempt at a Solution My prof never really explained how...

Homework Statement A thin, uniform, 3.8kg bar, 80cm long has two 2.5 kg balls glued on at either end. It is supported horizontally by a thin, horizontal, frictionless axle passing through its centers and perpendicular to the bar. Suddenly the right hand ball becomes detached and falls off, but...

I'm trying to model a Transfer function for the response of the deviation in temperature of water coming out of the concentric tube heat exchanger in response to an input velocity of water function. THE PROBLEM I start the derivation with a couple equations in Seborg's Process Dynamics...

Homework Statement a. Assume that yo dollars are deposited into an account paying r percent compounded continuously. If withdrawals are at an annual rate of 200t dollars (assume these are continuous), find the amount in the account after T years. b. Consider the special case if r = 10% and...

Homework Statement Ca3(PO4)2 + C + SiO2 --> CaSiO3 + CO + P4 Homework Equations The Attempt at a Solution I'm okay with balancing reactions that have 2 reactants but when there's 3 i take an extremely long time to do it. is there any easy way or strategy to go about balancing...

Hi all, I'm learning how to solve redox equations. I found the algebraic method to solve equations such as this one: Fe^{2+} + Cr_{2}O_{7}^{2-} +H^{+}\rightarrow Fe^{3+} + Cr^{3+} + H_{2}0 and i was able to solve it. What I don't see is how to use that algebraic method to solve an...

Hi everyone, I am currently reviewing for a thermodynamics exam and have come across a difficult problem while studying. Here it is: An insulated tank containing helium, a monatomic gas, at P1t = 1000kPa and T1 = 800K is connected to an initially evacuated insulated piston-cylinder device...

Homework Statement One mole of CO and 1/2 mole of oxygen are mixed and the products consist of CO2, CO, O2, and O. Write the atom balance for C and O. Homework Equations Mass conservation The Attempt at a Solution 1/2(O2)+CO2 -> aCO2 +bCO+cO2 +dO. a, b, c, d are unknowns. I make a table...

A top pan balance measures the force.So if I jump(or fall from a height) on it,Why does it show a greater value?(Acceleration and mass does not change,so the force is same)??

Hi, As part of a larger hobby project, I'm building a microgram balance based on the one described at Sci-Toys.com, but I believe my questions are appropriate for the "general physics" forum. Background: I purchased a 36" threaded steel rod, connected it to a razor, and then put it on a...

Homework Statement Write the charge balance for a solution containing H(+), OH(-), Ca^(2+). HCO3(-). CO3^(2-) , Ca(HCO3)+, Ca(OH)+, K+, and CIO4(-).Homework Equations Also, I am having a trouble understanding the concepts of mass balance and charge balance. The Attempt at a Solution The...

Hi: I am taking a radiochemistry class, and I am confused by beta plus decay. (1) p --> n + positron + electron-neutrino The mass of a proton is less than the mass of a neutron. In addition, the neutrino has mass as does the positron. (2) E = mc2 There must be come sort of...

The apparatus above has an initial angular velocity of \omega_{1} as the rods are released. I need to find the angular velocity \omega_{2} of the apparatus at the bottom. I've tried 3 methods. First I tried a work-energy balance where I included a gravitational potential energy. KE_{1} + PE =...

Hi, I've been wondering about the charge balance in the known universe, factors that might alter it, and the consequences of any small imbalance that might exist. This is a sort of layman's theory. I don't expect it to be right but I'd love to understand how it can be refuted. I am surely...

Homework Statement Consider an AC electricity system operating with a balance between generated power and the consumed power. Explain what happens to the frequency of a system if a large generator is suddenly disconnected. Explain the role of the governors of the remaining generators in...

Hi All Ive been racking my brains and i just can't remember how to calculate a 'seesaw' type balance point!? Please see the attachment - It am trying to work out what 'C' is (I know A, B & D) Thanks very much

We all know that a professor has many attributions such as teaching, administrative stuff and of course research. But, how you and your colleges deal with this? I've seen a lot of professors that find teaching very rewarding while other neglect the teaching part and just focus on research. I'm...

Figure Q4. illustrates a rotor assembly with out-of-balance rotor discs in planes A, B and C. The out-of-balance mass x radius products in planes A and C are as indicated in the figure. The out-of-balance mBrB in plane B and its angular position \ThetaB are such that the system is in static...

Hi everyone , I have a small question .. I have attached a ppt . I am having two sensors which can measure the weight of my object at two end position so fmy support .. My question is that can i find the angle beta if am having the value of X kg and Y kg .. your answers would...

Homework Statement Hi! I am currently learning how to balance equations in chemistry but something that I don't understand is using fractions to balance an equation. I have a problem that I can't work out because I'm so confused! The problem says: Complete and balance the acid-base...

The Problem: Bio fuels are receiving more and more attention. For biomass waste materials (cellulose, manure etc.), the first step in the process is typically to convert the biomass to sugar (glucose, C6H12O6). This first step is only able to produce 0.1 g glucose per g of biomass. The...

As opposed to guess and checking by inspection. Is there a method mathematically like with an algorithm or something to balance equations by hand (without the aid of any computer programs or anything like that except a simple calculator)?

1. What must the charge of a 1.45g particle be for it to remain stationary when placed in a downward-directed electric field of magnitude 650N/C? Homework Equations E = \frac{F}{q} The Attempt at a Solution So the field is pointing downwards. E fields point in the direction a...

Hi all, I was looking for some advice for my course as I have just entered the final semester of my final year and already find the workload overwhelming. I'm also trying to avoid leaving everything last minute like I usually do :) This semester I have 5 classes and a thesis to write(as...

solve (first three terms) $y''-(2+x^2)y=0$ using the method of dominant balance (for large x). I solved this and got 4 different solutions when I think I should be getting 2.

Several articles I've read describing one theory of how everything could have started from nothing. State that all the energy of nothing equals zero as gravity is negative energy. One of those articles was written by Stephen Hawkings. He also stated that quantum fluctations will always exist...

Homework Statement The mass of the Moon is 7.35*10^22kg. At some point between the Earth and the Moon, the force of gravitational attraction cancels out. Calculate where this will occur, relative to Earth. Me = 5.98*10^24 kg Mm = 7.35*10^22 kg D = 3.84*10^8 m g = 6.67*10^-11 Nm^2/kg^2...

I have been shooting both a Vertical Crossbow and a Horizontal Crossbow, I find that I shoot the vertical crossbow (off hand or free hand, without a rest) much more accuratlly than I shoot the Horizontal Crossbow, Is there a technical reason why? Most all vertical compound bow shooters (shooting...

On the flat bottom of an aquarium is an old fashioned balance. On one scale of the balance is a piece of plumbum, on the other side is a piece of iron. The scales are exactly in balance. Now we let the aquarium fill slowly with water, until the entire balance is under water. What happens now...

Homework Statement A cup of water has weight X. A stone has weight Y in the air is immersed fully in the cup and it displaces water of weight Z. What will be the new reading on the balance after the stone is immersed inside the cup? Homework Equations The Attempt at a Solution My...

I'm a little confused, in my fluid mechanics course we've covered many equations and they are all derived using an x-direction fluid flow. If I was to use these in a system in which fluid flowed in the y-direction would I have to re-derive them? Or would it be more of a case of using a...

This may seem like a really dumb question, but I can't figure out what the answer is, so please just bear with me. Why does a balance that is equal come out straight? If one side is tilted slightly lower than another, shouldn't it just stay that way since the masses are the same on either...

THANKS, I ONLY NEED HELP #2 NOW, PLEASE 10/31/12 @ 9:10 pm bumpHomework Statement 1)If the fulcrum of a 0.1 kg meter stick was placed at the 40 cm mark and a 200 g mass at the 0 cm mark, would it be possible to balance the meter stick with a 200 g mass on the long side of the meter stick? What...

Hi, first post newbie here, so go easy please:smile: I'm trying to get a grip on the understanding of a car cooling system for a friends race car. It seems the more I look into it the more questions I'm left with. For this post I would like to clarify the coolant side, leaving the air side...

Attached pdf contains the problem, and my progress in working it. My question is, I'm not really sure how to proceed. Anyone care to push me in the right direction?