Rate Definition and 1000 Threads

(context) I can remember reading about an atomic clock that could show time running slightly differently rates at different heights, due to the differences in gravitation. Is it realistic to think of it the other way round, ie gravity as an effect of miniscule time rate difference ? If an...

It seems there must be a way, but I cannot seem to wrap my head around it. Here's the scenario... I have a 24" line flowing with a wet gas (combustion flue gas) into a dryer. It comes in at 90 degrees F, at a rate of 180 SCF/M. It leaves the dryer at 73 degrees F at a rate of 124...

Homework Statement An Inductor L and a Resistance R are connected in series with a battery of emf E. Find the maximum rate at which the energy is stored in the magnetic field. Homework Equations Energy stored in an inductor : U= 1/2Li2 For a simple LR circuit with a DC voltage source the...

Say you have a rectangular channel with a width, w (m), and a height, h (m) and an infinite length. The channel itself is fixed and none of the sides can move with respect to one another. If you know the volume flow rate, V (m3/s) of fluid through the channel, how do you calculate the shear rate...

I would like to find the 12 to 19 abortion rate per 10,000 women from the following table: This would be the merging of age groups "12-17" with "18-19" to some how get the 12-19 abortion rate. EDIT: "Distribution of abortion age" was translated from "Répartition des ges l'avortement" in...

Homework Statement Consider the slab shown in Fig. 18-18. Suppose that L 25.0 cm, A 90.0 cm2, and the material is copper. If TH 125 C, TC 10.0 C, and a steady state is reached, find the conduction rate through the slab. Homework Equations Pcond = Kc *A*(TH - TC)/L K = 401 W/m*k The Attempt at...

I have a work related question. Although it seems like a relatively simple question, I am having difficulties finding the correct equation(s) to calculate the answer. Question: Given a fixed volume air tank filled with pressurized air, how does one calculate the flow rate over time through...

Hey people, I have a pressure vessel pressurized to say 20MPa at 33C, of which I'm working with a gas (scCO2 to be exact) which will then be released into the atmosphere (standard pressure and temperature) through a release valve; I'm wondering how long it will take for the pressure to reach...

Homework Statement A 700g ball rotates around a vertical shaft supported by two strings. If the tension in the upper string is 20.0 N, determine (I have attached the file) a. The tension in the lower string. b. The rotation rate in rpm of the system. Homework Equations [/B] F=ma F= m...

I have this problem: Consider the next state for the EM field: ##|A\rangle=\frac{1}{\sqrt{N!}}\left ( \int e^{-k^2} \boldsymbol{a}^\dagger_{k,+} \right )^N |0\rangle##. There is a particle in the unique bound state for spherical potential ##V(r)=-\delta ^\prime(r)/r##. for absorb a photon if...

Homework Statement Water vapor at 6 MPa, 600C enters a turbine operating at steady state and expands to 10 kPa. The mass flow rate is 2 kg/s, and the power developed is 2626 kW. Stray heat transfer and kinetic and potential energy effects are negligible. Determine (a) the isentropic turbine...

I'm trying to learn more about how air compressors work (not how they mechanically function - how they're input/out pressures and flow rates work) and I'm having a lot of trouble getting a specific questioned answered even after a lot of google searching. Suppose I have a compressor that the...

Homework Statement A composite pipe made of steel pipe ( ks = 16 W/m.K) of inner and outer radius of 0.5 and 1.0 cm and a plastic pipe (kp = 0.092 W/m.K) of inner and outer radius of 1 and 1.25 cm, respectively. If the inner surface of the steel is maintained at 900 °C and outer surface of...

First time caller, I'm a newb so go easy on me. So I was trying to work through a calculation to figure out the precession rate variation in terms of the Precession of the Equinox. I came across the following formula from...

I have a diesel pump doing 900 lpm with a hose reel 30 meters long, the inside diameter of the hose is 32mm. The frictional loss for 30 meters of hose is 461.04 kPa. The Viscosity of Diesel is 4.5 mPas. I would like to know the final flow rate. thanks in advance

Hello Maths Help Board Users, I was hoping for some guidance on the following problem. Thanks in advance for your contributions and time. "A fish population grew according to the following quadratic model - the number of fish on day t is given by P (t) = 800t - t2" Q) Find the average growth...

Hey guys. I could use some explanation since I am new to FM: So my problem is the following one: Fluid flows with an average velocity 8 m/s in a pipe with diameter 3m. What is the volume flow rate? Now, I think the formula I got to use is Q= v.A Yet, I found my solution from a formula I found on...

Hi, I would appreciate it if someone explains the difference between these two phases regarding a coil rotates in a uniform magnetic field. 1. The rate with which the coil intercepts the lines of magnetic field in the dynamo is maximum when the plane of the coil is parallel to the lines of the...

Homework Statement More a report question but unsure where to put it. Take a 5mL syringe and a 10mL syringe (both filled to 5mL) with the plungers removed. Time how long it take to full drain each syringe Make a statement regarding your results. Homework Equations Fluid flow rate = volume /...

So I recently learned that Teslas use AC induction motors rather than DC motors. Now I always assumed that DC motors would be easier to control the speeds of vs. induction motors, so it surprised me that they used an induction motor in the Teslas. Now in my old days I had heard that induction...

I was reading about strain rate tensors and other kinematic properties of fluids that can be obtained if we know the velocity field V = (u, v, w). It got me wondering if I can sketch streamlines if I have the strain rate tensor with me to start with. Let's say I have the strain rate tensor...

Homework Statement Find the rate of change of the area of a rectangle whose area is 75cm^2. The length is 3 times the width. The rate of change of the width is 2cm/second. Homework EquationsThe Attempt at a Solution A=75 A'=? L=3x= 15 L'=6 W=x=5 W'=2 A'=L'W+LW' A'= (6)(5)+ (15)(2) A'=60cm/sec

Homework Statement There is a paper in 1973: T. Kushida, "Energy Transfer and Cooperative Optical Transitions in Rare-Earth Doped Inorganic Materials I. Transition Probability Calculation", J. Phys. Soc. Jpn. 1973, 34, 1318-1326. DOI: http://dx.doi.org/10.1143/JPSJ.34.1318 that explains the...

Hello, I want to find the mass flow rate of flue gas, i have only the diameter of pipe and ID fan speed which are 1.48Meter and 980 RPM respectively

Hello! How is the count rate of a detector defined (I need for a scintillator)? It is just the number of particle hitting the detector per second times the efficiency of the detector at that energy?

Hi, So I am currently working on a rather simple problem of a projectile being launched by a spring at a certain angle. Ignoring friction, from conservation of energy we know that the velocity of the launched projectile would be ##v = \sqrt{\frac{kx^2}{m}}## (with ##m## being the mass of the...

Homework Statement Consider the process of decay of a muon into one electron, one electron antineutrino and one muon neutrino using the Fermi theory. Assume the matrix element is, ignoring the electron's and the two neturino's masses, |\mathcal{M}|^2 = 32G_F^2(m^2-2mE)mE being E the electron...

I have completed a 2D finite difference code in MATLAB that has a domain of (0,1)x(0,1) and has Dirichlet Boundary Conditions of value zero along the boundary. I get convergence rates of 2 for second order and 4 for fourth order. My issue now is that I'm now wanting to change the domain to a...

I am wondering if anyone has an idea of what typical acceptance rates to top nuclear engineering phd programs (e.g. MIT, Berkeley, U Wisconsin-Madison) are. I have looked and it seems that none of the departments release any numbers. If no one has any idea, does anyone have a perspective for...

I'm trying to solve one of the problems in my textbook (Atkins Physical Chemistry) and I just can't get it out. Here's the problem: "The data below apply to the formation of urea from ammonium cyanate. Initially 22.9g of ammonium cyanate was dissolved in enough water to prepare 1.00 dm3 of...

Homework Statement A fireman's hose acting as a water cannon, directs 100 litres/s (100 kg/s) of water horizontally at your chest at speed 5 ms-1. Assuming water essentially falls to the ground after hitting your chest (rather than say reflecting horizontally backwards), what horizontal force...

Homework Statement Given a detector with 500 pixels, and a pixel size of 5 um, is it posible to register next signal? I = cos(2 π 4 x) were x is expressen in umHomework Equations fs = fs/2 The Attempt at a Solution My problem is with the pixel size, I mean, the sampling rate will be...

Homework Statement Hi guys, it a very simple question, but it causing me a great deal of confusion. The questions are as follows: So I worked out the ans for one which I have displayed below. But what I don't understand is what they want from the second question. Because the way I see it...

If the universe is expanding at an accelerating rate, either through a "pushing" or "pulling" force in a direction, and we have come from a "big bang point", then I wonder if we could calculate all our vectors at anyone moment and time to find the universal acceleration point and direction. If...

Homework Statement A.[/B] Someone is walking outside when the temperature of the air is -10°C. The metabolic rate of walking is 140 Cal/m2hr, and the usual muscle efficiency (20%) applies. They are completely covered by clothing with a coefficient of thermal conductivity of 0.36 Cal-cm/m2hr...

If dark matter is responsible for the inner stars within a galaxy rotating at the same rate as the outer stars, then why is it that murcury rotates at a faster rate than say pluto.This posses the question why are we searching for evidence of dark matter deep in the Earth when there seems to be...

Hello If I travel toward a strobe light, will the flash rate appear to increase? If it does, would that then mean that the light entering your eyes was entering faster than the speed of light? If the strobe flash rate does not increase then this universe is stranger than I thought. I have been...

Homework Statement Due to formatting problems, I have attached the problem below. Homework EquationsThe Attempt at a Solution Plotting the appropriate graphs and based on linearity, I have determined that the reaction is first order with respect to [O2] and second order with respect to [NO]...

1. Homework Statement Due to formatting problems, I have attached the question below. The attempt at the solution: I am not sure how to deal with the hydroxide ion since it is written above the arrow. I believe that this signifies a species not included in the overall reaction but is...

Hi When I was writting my thesis I found in an article, published in International Journal of Heat and Mass Transfer, an unit of mass flow rate G - kg/(m^2*s). Isn´t it wrong? I think that the unit of mass flow rate is kg/s. Would you mind helping me to figure it out? Thanks.

How did this definition come to Newton's mind? Force seems to be the effort we apply. So, qualitatively, more the effort, more the force. How to understand intuitively that this formula given by Newton gives a quantitative measure of Force? And, how do we know that Force does not depend on more...

In the case of a kidney vessel from point a to point b(a-------------b), say we constrict point b and increase resistance. Would the flow rate be decreased before the constriction at b, or would the flow rate only be changed after the constriction. Thank you Physicsforums!

Homework Statement Classify the following actions based on how they could affect a reaction rate (rate increases, rate decreases, rate is unaffected) and provide a brief explanation as to why: Add a catalyst Decrease the concentration of a reactant Decrease the surface area of a solid reactant...

I am wondering if anyone has determined by experiment or calculation at what rate or even better what frequency the quarks move around at inside a neutron and proton? Do neutrons or protons vibrate at a specific frequency.

I've been digging through literature the last few days, and I'm starting to wonder if increasing strain rate EVER decreases yield stress? I found anomalies which increase it with increasing temperature. But I cant' find the reverse, so I was wondering if it was possible?

Hi Friends, I am Milind Nachane, New member of PF. We have to buy a Water Treatment Device which eliminates the scaling and rusting Hazard. To decide model of device we need to know Flow rate of Pump. I know that Pump is Mono-block (Non-submersible) of 7.5 Hp and has 2 Inches Diameter...

I have a basic question for my own understanding of things, Consider a straight horizontal piece of Ø15 mm pipe (inside), 20 meters in length, with 5 bars static pressure connected to a water main. Trying to find out what the flow rate through the open end of the pipe will be, doesn't seem to...

Hey everyone!Here's my first post in the forum!You probably usually discuss more substantial issues, but I'm having troubles and I'm sure you can help me!I'm trying to calculate the size of an ideal circular hole in a vacuum vessel given the measured leak rate in mbar l/s (helium spray leak test...

Hi all this is my first post. Okay I can have a rifle cut into a barrel at any twist rate I want, so I want to see if a cycloid can work for what I want. Now most twist rates are static so as an example one barrel may be 1 turn in 12 inches for 26 inches an example of what is called a gain...

Hi folk, i need an help for this esercise. 1. Homework Statement Determines the rest mass lost by the sun every second for emission of radiation. It assumes that the surface temperature of the sun is 5700 K and the diameter ##D_s=1.4 × 10^9 m##. The Attempt at a Solution The solar nuclear...