Rate Definition and 1000 Threads

Homework Statement An initially pure 3.4 g sample of Ga-67, an isotope with a half life of 78 hr. What is its initial decay rate? Note: Molar Mass values given in tables for chemical elements are for natural mix isotopic ratios. (i.e. the relative percentages of each isotope normally present...

when an object moves relative to something it experiences time at a slower rate right? now let's assume that an rocket moves 99.99% the speed of light, then what will be the rate of fuel consumption? will it remain the same or it will increase/decrease?

Homework Statement A beam of thermal neutrons (10^12 neutrons per cm^2 second) strikes a 1cm thick water target normal to its surface. The target is a round disk with diameter 20cm. Find the exposure rate (R/second) 100cm beyond the water target (the middle of the disk) from only the...

From my research I am showing that if an input signal becomes too slow (ie: a low slew rate) then the noise can cause multiple state changes. But I am being told that if the slew rate is low then it will get rid of unwanted noise. I read my results from this: (I lost the link but I did copy...

Do systems further away from equilibrium increase entropy faster than a system with a high level of entropy and does this increase push the universe towards thermal equilibrium faster. Is there anything stopping the universe from reaching thermal equilibrium?

I have a condenser with a mass flow rate of 60kg/s, an initial point 1: P=50kPa, Quality = 95% and a final point 2: P = 50kPa that is saturated liquid. cooling water flows through the condenser with a mass flow rate of m(dot) and has a delta temperature of 15 degrees Celsius. how do i...

hello In venturi meters, orifice plate meters and generally when there is a neck, constriction at a point in a pipe there is, at that point, a drop in pressure and an increase in velocity, so that the whole energy is preserved (theoretically) my question is, why if we increase the flow rate...

Homework Statement See Diagram Homework Equations See Diagram The Attempt at a Solution I have been looking for hours for the correct formula but do not know what to use or where to start. If you can point me in the direction of the right formula if one is needed, and I would be very...

I am in need of a formula to calculate mass flow rate of liquids through a known orifice size and known pressure/secondary pressure. I need to do this for multiple liquids and I know the specific gravity for each liquid. can anyone help with this formula.

Hi everyone, this is my first thread i hope i do it right. I will get right into it by saying, how can i prove that : w=w0*(1±4πƒv/g) Where "w" is the weight of an object moving along the ecuador, v is it's velocity and g is the gravitational acceleration. I have...

When is the rate of change of momentum equals zero ?

What If we accept starting point of the big bang as the central point and what If the equatorial expansion rate of a spinning universe was the speed of light, how would it impact universe? ( In this question, you may think yourself as an observer from out of universe. I try to mean with "the...

Homework Statement A hose with a nozzle 80 mm in diameter ejects a horizontal stream of water at a reate of 0.044 m3 s-1. With what velocity will the water leave the nozzle? What will be the force exerted on a vertical wall situated close to the nozzle and at right-angles to the stream of...

Homework Statement This is the question: Consider the reaction: $$2NO_2(g)+O_3 (g)\longrightarrow N_2O_5 (g)+O_2 (g) $$ The reaction of nitrogen dioxide and ozone is first order in ##NO_2(g)## and in ##O_3 (g)##. Which of these possible reaction mechanisms is consistent with the rate law...

It's known that the nuclear reaction rate (inside a Star) can be determined with $$R_{ab}=n_a n_b\left<\sigma v\right> \, \approx \, n_a n_b \Big(\frac{8}{\pi m_e}\Big)^{1/2} \frac{S(E_0)}{(k_BT)^{3/2}} \Delta \frac{\sqrt{\pi}}{2} e^{-3E_0/k_BT},$$ where ##k_B## is Boltzmann constant, ##T##...

I am a part C mechanical engineering student and require some advice for my individual project, which is based on the high strain-rate testing of a particular glass filled composite material using a split-Hopkinson pressure bar (SHPB) experiment. I gathered the results on a SHPB test rig and...

A car is purchased by 12 million by paying 48 monthly fee due to x each quarterly fee due and 400 000 each for four years . If a rate of 44% effective annual, determine the value of x . Answer from textbook is $353 137.09 Ussualy, in problems I've seen, annuity is separated, but here is...

Homework Statement A 0.8m high and 1.5m wide double pane window consisting of two 3mm thick layers of glass(k=0.78W/mK) is separated by a 10mm wide stagnant air space(k=0.026 W/mK). The convection heat transfer coefficients on the inner and outer surfaces of the window are 10W/m^2K and 35W/m^2K...

I've Attached the question and my answer to question 1 to task 3 and guidance if I've done it right? Or any guidance?

I want to create stress/strain curves for Higher Strain Rates from an available stress/strain curve? I am interested on the mathematical formulation aspect to generate a Dyna Material card.

Homework Statement Diffusion coefficient (D) of 100 nm particles ( density = 1050 kg/m3) in a viscous solvent at 25 C is 2.2 x 10-13 m3/s What is the average shear rate at the particle surface? Homework Equations D = kT/ 6πηa (1) where k is Boltzman constant, T = temperature, ηsusp =...

Let's say we have two samples of pure Helium-4, and two other samples of pure hydrogen fluoride (consisting of Hydrogen-1 and Fluorine-19) all in separate containers. One container of each chemical is at the same initial temperature of 200°C at a pressure of 101kPa, and the other ones are at...

From particle data group,(http://pdg.lbl.gov/2014/listings/contents_listings.html) I can see the decay branching ratios of N(1875),but the total width is not found.The "Breit Wigner width " are very different.So my question is ,How do they get the branching ratio without a certain total width?

Homework Statement Overall reaction: A + F = I + J (just take = as the equilibrium sign) It is first order in both A and B. The following mechanism has been proposed: 1. A + B = C + D 2. C + D = E + B (B is the catalyst) 3. E + F = G + H 4. G + H = I + J These are all...

Homework Statement A patient receives an injection of 1.11×108 Bq of 131I,30% of which goes to the thyroid, having a mass of 20 g.What is the average dose rate in the organ? Homework Equations D=1.60×10–10AE Gy s–1 The Attempt at a SolutionA=(1.11x108x(30/100))/20=1.665x106Bqg-1 E=0.192Mev...

So I'm trying to model the process of towing an iceberg from Antarctica to elsewhere to use for fresh water. I hit a dead end trying to find how much of the iceberg would be left. I know it takes 333 J/g to melt ice and the mass of the iceberg is 7 million tons so i know how much energy it...

A patient receives an injection of 1.11×108 Bq of 131I,30% of which goes to the thyroid, having a mass of 20 g.What is the average dose rate in the organ? Solution: D=1.60×10–10AE Gy s–1 A=(1.11x108x(30/100))/20=1.665x106Bqg-1 E=0.192Mev =1.60x10-10 (1.665)(0.192Mev) = 51μGy s–1 This is...

Homework Statement I need help for this kinetics question: Chlorination of butene at 0 degrees c, liquid phase, dichloromethane as solvent. initial concentration of butene is 0.1M conversion of 47.71% achieved after 3.1 hours. an additional 0.5M of hot butene was added at this point, which...

Hi Guys, I'm solving this for almost a week, this is a part of our probset in chemical kinetics: The thermal decomposition of dimethyl ether: CH3OCH3 ---K1--> CH3' + OCH3' CH3' + CH3OCH3 ---K2--> CH4 + CH2OCH3' CH2OCH3' + --k3---> CH3' + HCHO CH3' + CH2OCH3' ---k4--> C2H5OCH3 using steady-state...

Homework Statement Nitric oxide and oxygen gases react to form nitrogen dioxide gas in the reaction 2NO + O2 -> 2NO2 Write a mathematical expression to represent the rate of production of nitrogen dioxide: 4.0x10-3mol/(L*s) Homework Equations r=k[X]m[Y]n The Attempt at a Solution Not...

My textbook says: One of the decays occurs via a ## b \to c ## quark transition and is 'colour-allowed'.(Left of diagram). The other decay has a of ## b \to c ## and is 'colour-suppressed'.(Right of diagram) I'm unsure of what is meant by these terms, it doesn't really explain. I've...

Hello everyone, I'm new to this forum and this is my first post so go easy! I have an engineering problem which I am uncertain as to how to solve. I am trying to design a basic ballast system for pumping seawater. The idea is to use compressed air to evacuate the water through a series of...

Homework Statement Concentration of Hydrochloric Acid (mol/L) 3 2 1.5 1 0.5 Reaction Rate (s/M) 1.333 13.30 38.67 73.00 1466 Homework Equations r=k[H+]m (r is rate in M/s, k is constant, [ ] is concentration, m is order of reaction) The Attempt at a Solution I'm not entirely...

Does the mass flow rate differ depending on whether it's after the feedwater heaters or before the turbines or is it just constant throughout the entire system?

Hey fellas and ladies. So I have an issue. I've been exercising regularly for about 3 months now by doing jogging and brisk walking. Just basic cardio to get my terrible heart into shape. The thing is, I can't jog for very long at all without my heart rate jumping up to 170-180+. I know this...

I was trying to google it, but coudn't find any specific answer. Oxidation of Magnesium, for example, emits a lot of light. Is there a table of reactions by high much light they create ? What chemical reaction emits the highest number of photons per unit per time ? Thank you.

Is there a direct correlation between calorie burn and heart rate? If an athlete and a couch potato each weighed 175 lbs and ran a mile in 10 minutes, would they burn the same amount of calories? I would assume the couch potato would have a much higher heart rate during this event. Does that...

Hello everyone, I am quite new to Fluid dynamics, so I would like to ask for your help. Is it possible to calculate volumetric flow rate from the instantaneous pressure? We need to know the flow rate of the air entering the cylinder in the engine due to the suction pressure. It is required to...

I was doing my homework and really got stuck on one question. Not looking for just an answer as that is useless, I really want to understand how to do this problem as I have no idea how to involve some of the givens. UO_2 is a common fuel for reactors. If the fuel is enriched to 4 atomic percent...

I'm trying to look up sources on the nyquist sampling rate, but I keep finding this small subtle difference between sources, and I am not sure if it is laziness or some subtle point I am missing. Sometimes I see the nyquist rate as Fs>2Fm and sometimes I see it as Fs>=2Fm. So is it the sampling...

Hello! I have a PAL TV, and that means it is best for footage of 25fps and 50fps The TV's refresh rate is 200Hz Well, my questions are: What happens if I play an NTSC file on the TV? (≈30fps), since it doesn't go well with 200Hz much (isn't a multiple)... I thought about how would the TV...

Homework Statement Ina light bulb, billions of electrons flow through the tungsten wire bumping around, causing the filament to glow hot. Hot tungsten evaporates slowly, so its initial thickness profile r(x, t=0) can change over time. Consider a volume V of tungsten, with N bonds total, each...

Is flow rate at inlet of pressure regulator ( not relief valve) equal to flow rate at outlet ?

Hello, I am Primarily a Software Engineer, but have some background knowledge from my A-Level and Uni days. However, I have the following problem. I'd like to find out the rate of change in pressure across a valve. Here are the things I know about the system: Cv at 100% open = 0.004 (I...

Homework Statement R = 4000mi phi = 60 Me = 5.972E24 kg Mm = 5.972E16 kg distance of procession = 100 mi Homework Equations I know the answer is supposed to be ~1010 years. I also know what I am trying to do is have that e3 axis be pointing straight up, then when the mountain is placed on...

Hello guys, I need to calculate the flow rate for the following system. 2 lines of CO2 cyclinders at 60 bar. Each line (1/2'') goes to a 1/2'' PSV valve. Downstream the 2 PSV the line are collected together into 1'' pipe. The two PSV are identical and as per datasheet they have the following...

Homework Statement [/B] My question is regarding Part B of this problem, I have solved it but I'm wondering if there is another way to solve it since it says dtheta/dt and one of the hints I found online suggested that I use the chain rule. Homework Equations Q = mc(deltaT) Q/t = P The...

Hi. First of all, I should mention that I'm quite a novice in both physics and engineering. Let's consider an hourglass (or a silo) that is inclined at a constant angle. I'm unsure of how to calculate the necessary diameter of an orifice for a given mass or volume of granular matter to...

So I have a problem where I'm given the decay rate of a sample which contains Cs137, 10 mCi, and I'm basically given the percentage of radiation detected by the detector. But the wording of the question is: "What count rate would be observed in a perfectly efficient gamma detector" Sounds to...

Sand falls on to horizontal ground at the rate of $$9m^3$$ per minute and forms a heap in the shape of a right circular cone with vertical angle $$60^{\circ}$$. Show that 10 seconds after the sand begins to fall, the rate at which the radius of the base of the pile is increasing is...