Rate Definition and 1000 Threads

Hey everyone, I have a fluid system of water coming from a pressure source. Then there is a converging nozzle, which I have calculated the resistance coefficient using Crane's Manual and it has an outlet to the atmosphere. I have tried to simplify the system. The full system is a pressure...

So I have a 30" pipe that splits into 3 parallel paths, each 24" in dia. The pipes converge into a 30" outlet and then flows at about 40,000 gallons per minute at full head pressure. Assuming the same head pressure and one path closed off (i.e. now only flowing through 2 parallel paths), how...

So flow rate is calculated using only the parallel velocity to the area vector. Why is this? How can I mathematically prove this? Namely, how do I prove any perpendicular component of the velocity vector is not contributing to any volume output? I know this is the result of the dot product; I...

Observation of the growth of some beetle population suggests that discrete logistic equation would be more appropriate since these animals have distinct breeding season. discrete logistic equation: Xn+1=Xn+rXn(1-(X2/K)) the result of this equation accounts for population only season to...

How accurate do you think are the assessments made by students on this website??I had nothing but good things to say about all my professors. When I started in community college last year I joined late and had to take the professors whose classes were available. I did not even bother to check...

i want to find V(t) At first i found this problem was very simple but when i try to write differential equations i ended up with these V' = kA that's for sure then i confined the problem only to spherical shape and no other shapes of raindrops involved as i can't express A in term of V alone(...

Homework Statement A force is applied to a box 60 degrees from the horizontal. The box weights 5kg. If the force is 120N, and the surface upon which the box rests upon is frictionless, at what rate does the block accelerate? Homework Equations Fnet = ma Fg= mg The Attempt...

Hi, I've attached the problem that I'm trying to solve. I've also done the manual calculations to calculate Ithreshold. I'm not very good with MATLAB and I need MATLAB code for laser rate equations and I also need to plot LI characteristic of the laser. I_th=qV/(η_i τ) N_th=qV/(η_i τ)...

So I know that the rate of expansion of the universe is increasing, i.e. the 2nd time derivative of the size of the universe is positive. But, is the next time derivative (i.e. 3nd time derivative of the size of the universe) positive of negative? Do we have enough information to determine this...

There has been a flood of new data. Cosmologists have not yet settled on a new agreed value of H0. This may help lead to one. http://arxiv.org/abs/1406.1718 The 1% Concordance Hubble Constant C. L. Bennett (1), D. Larson (1), J. L. Weiland (1), G. Hinshaw (2) ((1) Johns Hopkins University, (2)...

Hi, The attachment below is about strain rate in fluids*. It shows how the strain rate d\phi/dt is related to the velocity field derivative du/dx when you stretch the element in x (i.e. longitudinal strain). It has no intermediate steps, and I can't see how the angle has been related to...

Homework Statement Determine the Strain Rate for a Material Fiber in the direction of the surface normal. The Velocity Field is V=((4y-3x)i+(5x+3y)j) ft/s http://puu.sh/9hQ7Q/2bda80620f.jpg is the picture which describes a steady, planar flow where i and j are unit vectors. Homework...

Hello All,I was given a problem today that I could use some guidance on. I have a compressed air pipe flowing into a container. This container has a pressure of 5 psi while the pipe has a pressure of 90 psi. There is a valve that controls when the air is released into the vessel and only...

I just want an alternative solution(preferably easier approach) to this problem "A" can finish a job two hours longer than "B". After working for 1 hour, "B" joins him and they complete the job in 3 more hours. How long would it take "A" and "B" to finish a similar job if each worked alone...

Hi, I was wondering if there was an equation for the flow rate through a straight vertical or angled capillary tube. All I can find is how to calculate the height it rises but I would like to know how to find the rate it rises. I imagine it is not a steady rate since it must stop once it...

Homework Statement The Wikipedia article on spatial rigid body dynamics derives the equation of motion \boldsymbol\tau = [I]\boldsymbol\alpha + \boldsymbol\omega\times[I]\boldsymbol\omega from \sum_{i=1}^n \boldsymbol\Delta\mathbf{r}_i\times (m_i\mathbf{a}_i). But, there is another way to...

Hi, is there anyone familiar with rate equation solving using Matlab? I need help on this

I want to consider the rate at which time slows as gravity increases near a massive object such as a sun or even a black hole. Obviously there is a distance component here but I am after a generalisation that simply shows the relationship between time and gravity (ought to be possible)...

Hi everyone, I'm currently a mechanical engineer interning at an HVAC company. I need to measure the resistance of a fluid through ductwork. The CFD shows a linear curve through a plenum when plotting R vs volumetric flow rate. For example, a straight rectangular box 1 1/16” by 2.5” and 3ft...

Homework Statement The space shuttle Endeavor is moving at a speed of 27870 Km / h. At takeoff, its mass is 2, 28 * 10 ^ 6 kg, however, its mass decreases as it uses its fuel: the engine burns liquid oxygen which has a density of 1141 kg / m^3, at a rate of 1340 liters per second. Calculate...

Hello, Im a student and I try to design a valve connected to a tank. However I have some troubles to define the phenomena. I have a pressurized tank with air at 100 bar and I would like to know the evolution of the flow rate through the opened valve. The valve outlet is at the atmospheric...

Calling kinetics experts: rate law from conductivity isn't possible!? Consider the usual primary halogenoalkane aqueous alkaline hydrolysis reaction RX + OH- --> ROH + X- We know the rate law is first order in RX and OH-. We could separately represent the drop in OH- conductivity as an...

Hello, I need some help understanding Bernoulli's principle, flow rate, velocity and pressure. I understand that when the diameter of a pipe decreases, the velocity will increase and the pressure will decrease. But I am having a hard time applying this to a practical application. For...

Homework Statement Hi all, I am helping in designing a conveyor that takes freshly milled mild steel bars and submerges them in a tank of cooled water to reduce their temperature enough to to not damage the proceeding equipment. The tank of water will be connected to a separate...

Homework Statement A rectangular opening is cut into the side of a large open-topped water tank. The opening has width W and height H2 - H1, where H1 is the distance from the top of the tank to the top of the opening, and H2 is the distance from the top of the tank to the bottom of the...

In euclidean quantum field theory, the imaginary part of the free energy, defined as the logaritm of the partition function, is it connected to the decay rate?

Hello Forum! I was wondering: In the rate law expressions, I could never find an example with a solid or a liquid in the reactants in my textbook (Chemistry by Zumdahl). I searched Chemistry (Raymond Chang) and Principles of Molecular Chemistry, without any success. What happens to...

Point $$P$$ moves at $a$ constant rate along the semicircle centered at $$O$$ from $$M$$ to $$N$$. The radius of the semicircle is $10cm$, and it takes $30s$ for $P$ to move from $M$ to $N$. $∠POM$ has measure $x$ radians, $∠OPM$ has measure $y$ radians, and $MP=S$ cm as indicated in the...

Hi all, I am having a homework problem that is statement really bothers me and I think it might be a typo. It goes in the following: Homework Statement A is a short life unstable state and it is in equilibrium with B and C. A\LeftrightarrowB A\LeftrightarrowC The equilibrium rate constants...

Homework Statement A circuit board has 20 integrated circuits(ic) with constant failure rate of 5 chips per million per hour (5FITs), 300 resistors(r) with a constant failure rate of 20 chips per million per 1000 hour (20 FIT), and 10 diodes(d) with a constant failure rate of 10 chips per...

Hello, At my work I'm working with testing the leakage rate of a gas system, and right now I am trying to gain some understanding of it all. However, there are some things which are very confusing to me, in regards to these rates. Searching the internet I find several different ways to...

I wanted to see how the rate of change of rate constant with temperature (dk/dT) changes with activation energy. I tried to do this with differentials: k=A*e-EA/RT so \frac{dk}{dT} = \frac{A E_A \cdot e^{-\frac{E_A}{RT}} } {RT^2} and then \frac{d(\frac{dk}{dT})}{dE_A} = A \cdot...

Light of constant intensity is incident on a metal surface, causing electrons to be emitted. State and explain why the rate of emission of electrons changes as the frequency of the incident light is increased. My answer: As frequency increases, energy of photons also increases, so more energy...

Homework Statement Here is the question: I am confused about the solution. In the solution they found that the minimum capacity rate ratio R = C_min/C_max was zero. This is because of the term I circled in the red which I do not understand why it goes towards infinity. Here is the solution...

Homework Statement The reaction v1A+v2B--->Products is 1st order wrt A and 0 order wrt B.If the reaction is started with [A0] and [B0] find the integral rate equation. The Attempt at a Solution I have got ln[A0]/[A0]-v1x=kt but answer is given as ln[A0]/[A0]-v1x=v1kt.Which one is right?

Let's say that you have an open tank of water and a hose connected to the bottom of it. Water is flowing out of the hose. You then cover half of the hose with your thumb. Will the flow rate (liters/second) right before you cover the hole be the same, less, or greater than right after you cover...

Is possible to compute the rate of change of x wrt sin(x)? ##\frac{dx}{d \sin(x)}##

A few years back I started a thread to make the point that there is a common misconception about main-sequence stars that their fusion rate sets their luminosity, in the sense that to know what the luminosity of the star will be, you need to know what the fusion rate is. In particular, you...

Marxian economics: Differentiating the "Rate of Profit Equation" While watching a recent Youtube video on Marxian crisis theory and the Tendency Of The Rate Of Profit To Fall, I decided to apply calculus to the equations to see what I got. The rate of profit is defined as ∏ = S / (C...

Just a curious question. How would the rate for a net reaction involving multiple steps of all similar (perhaps exact - i know it's highly unlikely) activation energies be calculated? I've been told to just look at the slowest step (highest EA) in all cases, even if they are similar in...

Homework Statement The average counting rate of a radioactive sample is 486 cpm (counts per minute). Find the probability that in any given 10s interval one gets less than 72 counts. Is this the same as the probability of getting less than 72 X 6 = 432 counts in 60s? Homework Equations...

A helicopter is flying to the right (in the +x direction) with a constant speed v, carrying a package of mass M suspended below it using a cable as shown in the figure (you can assume that H and L are not changing with time). Choose the package as your system. What is its rate of change of...

I'll start with what I do know: [SIZE="2"]Shannon Law gives the theoretical upper limit C_{noisy}=B*log_{2}(1+\frac{S}{N}) if S = N, then C = B As N→∞, C→0 As N→0, C→∞ Nyquist Formula says approximately how many levels are needed to achieve this limit C_{noiseless}=2*B*log_{2}M (If you do not...

One plane is flying due east straight and level at 30000 feet and at 420 mi/h. A second plane flies due north at 40560 feet and at 480 mi/h. The second plane crosses above the flight path of the first plane 2 minutes after the first plane passes that point. How fast were they approaching each...

Why an increase in the volume of output cause interest rate to rise? Any one can explain thoroughly?

Homework Statement Patients with certain heart problems are often treated with digitoxin, a derivative of the digitalis plant. The rate at which a person's body eliminates digitoxin is proportional to the amount present. In 1 day, about 10% of any given amount of the drug will be eliminated...

Suppose in the reaction 2 NO + O2 --------> 2NO2 Why when the the concentration of NO is doubled, the rate increases 4 times, I know that the rate is directly proportional to the square of NO concentration (I don't know why) and it's order of reaction is 2 ( I don't why ). but I still can't...

Hi everyone, I have a question on the rate constant of a kinetic model(like the one we use in describing chemical reaction). Suppose we have the following model between two states A and B: A--(a)-->B A<--(b)--B where a, b are the rate constant for the transition. So the corresponding...

I am simulating a system where I have as a function of time the rate at which something happens, like for instance n atoms per second passes a boundary. Now what happens in the system is that as soon as one atom passes the boundary, everything goes back to initial values. So my problem is that I...

Homework Statement The underside of a smoky layer 7m x 10m is radiating like a flat, isotropic plate at 440°C to the floor of a compartment 1.85m below. The mean emissivity is 0.45 and the floor is homogenous/flat plate at 40°C. What is the rate of heat transfer from the smoky layer to the...