Rate Definition and 1000 Threads

Thank you for taking the time to read my thread. I do not agree with the TA's correction of my quiz and would appreciate if someone could give it a look before I approach him about it. Homework Statement Cobalt-60 has a half-life of 5.24 years. How long would it take for a 100 mg sample of...

Hi all I'm sure this has been asked before and I'm hoping someone be kind enough to direct me to the answer. Which is probably 'you're question is nuts' :) Particles interact with each other and this affects the probability of where they are? Right so far I hope. This probability has to be...

Hi all, I need to model an hydraulic cylinder with simulink and to control it according to some rules. What I don't understand is to find a relationship between the flow rate and pressure inside it. Any suggestion is appreciated. Thanks

I am just a hobbyist and try to learn for myself. I understand that the value of a field and its rate of change play the same role of position and momentum of a particle with respect to Uncertainty Principle, i.e. both pairs are conjugate variables. My question is: does the rate of change of...

Equation of standing waves→ y=Asinkxcosωt What do i get if i differentiate the above equation with respect to "x" ? Do i get the rate of change of amplitude when i put t=0?

Here is the question: I have posted a link there to this topic so the OP can see my work.

Homework Statement A diver jumps from a 13m high tower, and hopes to complete 212 somersaults. what should be the rotation rate be Homework Equations The Attempt at a Solution 13 m = (1/2)(9.81 m/s²)(t²) t = 1.628 s ω = 2.5 rev / 1.628 s ω = 1.53 rev/s I'm still...

I am in a lab class and we are currently measuring count rates for a specific source. Yesterday we ran a program that runs 3 second gate times on a CS-147 source with a voltage of 500v running through the detector, and a threshold of .5v on the counter. This 3 second gate time was to be repeated...

Here is the question: I have posted a link there to this topic so the OP can see my work.

Hi PF, I am trying to get a good explanation regarding time dilation and how it works. I want to understand why we can't slow an objects inertia down enough to see it age faster than we age at our velocity. I will try to use a reference which is understandable to everyone. So, an easy...

Hi we know the relation between wavelength, frequency and energy : The greater the energy, the larger the frequency and the shorter (smaller) the wavelength -> E=h\upsilon On the other side, SAR is common property that measures absorbed energy. Now if we calculating SAR for human brain...

Hi everyone Firstly this is not a homework question, i work in transport engineering. ( i do study part time which is why i sometimes post in the homework section) Now to the problem. I am trying to understand how to solve this problem, i already know the answer. A train is traveling...

I was looking at a site which described the classic demonstration to illustrate how water pressure increases with depth (shown by punching three holes, one above the other separated by a few centimeters, in a container of water): "The smaller the holes, the greater the rate of flow from the...

I'm trying to figure out some things regarding leak rates. I have a system which is constructed to adhere to UHV standards (total leak rate < 10^-10 Torr*L/s), baked out and evacuated to 10^-9 Torr, and then backfilled to about 600 Torr with N2 and Xe. So, there's a leak of air from the outside...

Homework Statement A truck traveling at 40.0 m/s decelerates uniformly to 20.0 m/s over a distance of 100 m. Determine the rate of deceleration and the time required for the truck to travel the 100 m. Homework Equations Deceleration=(original velocity-final velocity)/Time The...

Folks, I was reading the Cacuci Handbook of Nuclear Engineering, and he defines two times the conversion rate, once as: C= fissile produced/fissile consumed but later as : C= transuranic produced/transuranic consumed and said that the breeding rate is the former but for fissile...

Is there any thing that could, or any way to increase the atomic decay rate of already unstable elements, such as the radio active elements. magnetically or otherwise, even if the thought is only plausible or otherwise theory, I wouldn't mind hearing it. A thought accord to me, what if...

Sorry if my questions are rather naive, this is my first post on this forum. Whilst burshing my teeth, I was watching water drain from the sink and came up with a few rather curious questions. Does the ingest of matter suggest by black holes suggest that the pressure of our universe is...

1. Forgive me for this novice question, but can variation in the expansion rate of the universe, be partially explained by an increasing number of stars turning mass into energy, hence reducing gravitational attraction between galaxies, and at the same time applying radiation pressure (a small...

Lets say you have the reaction aA + bB => cC + dD The rate of the reaction is given by the change in initial concentration over the change in time. -\frac{\Delta \left[ A \right]}{a\Delta T}\; =\; -\frac{\Delta \left[ B \right]}{b\Delta T}\; =\; \frac{\Delta \left[ \mbox{C} \right]}{c\Delta...

I'm sure we've all envisioned bombs made by allowing macroscopic quantities of antimatter to react with ambient matter thereby releasing vast quantities of energy in very short time scales. I'm wondering how realistic this actually is. Suppose I have a 1 kg chunk of anti-iron in the middle of...

Note: this is not a homework question; this is strictly conceptual in understanding the equations at work in this scenario. The tank is vacuum-insulated, the liquid is saturated, and the vents have just been opened in order to vent down the ullage pressure. My question is simply how do you...

Hey all, I'm trying to simulate a simple chip-heatsink situation in SolidWorks using their thermal modeling suite. I have found an ideal set of parametric values for the chip to work at a reasonable temperature, but I need to figure out what the convection coefficient means in terms of air flow...

Hi All, I'm designing an exhaust system in brewery. Does anyone know the recommended air changes (ventilation rate)? My concern is the elevated level of carbon dioxide during the fermentation process. I'm planing on exhausting the air thru sidewall propeller fans and make-up the air thru roof...

"What is the heat flow rate [...]?" Homework Statement The problem is: "A copper tube (length, 3.0 m; inner diameter, 1.500 cm; outer diameter, 1.700 cm) extends across a 3.0-m long vat of rapidly circulating water maintained at 20 °C. Live steam at 100 °C passes through the tube. (a)...

Homework Statement Write a simplified algebraic expression, in terms of a and h, to estimate the instantaneous rate of change of the profit for each numeber of athletic shirts sold. Use h = 0.1. The Attempt at a Solution { -0.25(1000+h)^2 + 4(1000+h) + 12 - [ -0.25(1000)^2 + 4(1000)...

Dear all members, I just need anyone of you to verify my system and some equations I have worked out for my problem below. Please feel free to point out any flaws in my reasoning and formula applications. Problem Definition: Two flat blocks (different materials, Fiberglass and Rubber) rubbing...

so this is what i know: m=ρ*V*A ρ = 0.669 ρ (kg/m3) for Methane (gas) I think... A = flow area = ( D^2/pi) units are m^2 I think for a pipe I really think this is wrong V = M * sqrt (gam * R * T) R = Universal Gas Constant = 8314 J/kmol-K. T = temperature gam = K = 1.304 for Methane...

Homework Statement A soccer ball is kicked into the air from a platform. The height of the ball, in metres, t seconds after it is kicked is modeled by h(t) = -4.9t^2 + 13.5t + 1.2. I solved for the expression that represents the average rate of change of height over the interval 2<= t <=...

Homework Statement I want to compute the following integral I=\int_0^1 f(x) dx for a function f(x) such that the integral I cannot be evaluated analytically. f(x) is a known function. Therefore we want to obtain I numerically. To do this we want to use the Trapezium method with...

Hello! I was wondering if somebody could help me develop an answer to the question below. I would like to calculate a rate of change of the following function: θ = arctan (a * (tan β)) where "a" is a constant. By the way, the shape of the curve -- angle alpha as a function of angle...

I've got a problem regarding tensors. Premise: we are considering a fluid particle with a velocity \mathbf{u} and a position vector \mathbf{x}; S_{ij} is the strain rate tensor, defined in this way: \displaystyle{S_{ij}=\frac{1}{2}\left(\frac{\partial u_i}{\partial x_j} +\frac{\partial...

Homework Statement Look at the image.All the O's are of equal length.O1=O2=O3 etc.Angles are subtended from two ends of An O to point P.As you see,O1's angle is larger than O2 ant )2's angle is larger then O3 and so on. As you Go down the O's(i.e. O1,O2,O3 etc),the angle subtented by the O's...

Is there anyway to figure out the distance at which the universe is expanding (rate of stretching) at a rate that is equal to the speed of light?

Homework Statement This is not my homework I'm a self-learner and I faced a problem solving these two problems and I found nobody to help me to solve them, I hope somebody here will help. The two problems are : 1- An airplane is flying at a constant speed of 360 mile\hr and climbing at an...

https://www.khanacademy.org/math/calculus/derivative_applications/rates_of_change/v/falling-ladder-related-rates Homework Statement Essentially, the question states that a ladder, with length 10ft, is laid up against a wall with its bottom 8ft out. The ladder begins to slip, on a...

https://www.khanacademy.org/math/calculus/derivative_applications/rates_of_change/v/falling-ladder-related-rates Essentially, the question states that a ladder, with length 10ft, is laid up against a wall with its bottom 8ft out. The ladder begins to slip, on a friction-less surface, at a...

Uncertainty--what is the rate with 0.59% precision?? Homework Statement Assume that negligible uncertainty in timing of a clock, calculate the number of counts required to measure a rate with 0.50% precision. Homework Equations The least accuracy is 0.50%? The Attempt at a Solution...

Need some help here! My plant just installed a water scrubber for controlling methanol emissions. Results obtained from stack tests have consistently shown the flow rate of the gasses from the scrubber outlet is about 30% of gas flow rate into the scrubber. From process knowledge, most of the...

Hi all, Doing some calculations on an air-cooled heat exchanger at the moment and could use some help understanding the variation of air-side heat transfer coefficient (htc) with flow rate. It's more of an intuitive problem really as I'm okay with the math, etc. So I know that as you...

Hi Reading another post about the inverse square law by trewsx7 on this forum, I had the idea that maybe the gravity field isn't constant at some parts. Imaging a 2-dimensional gravity field produced by a source. Considering ∏, there might be a repeating infinitesimal patterns on ∏ where...

I know how to calculate transition rates between nl resolved states in a hydrogen-like atom, but I don't know how to calculate transition rates between nljm states. I know that dipole transition rate is \frac{32}{3}\frac{\pi^3 \alpha c}{\lambda^3}\left<\psi_1|\mathbf{d}|\psi_2\right> The...

I was wondering how fast x! grows as it approaches infinity as compared to x2, 2x, and xx. The last one was fairly obvious since x*x*x*x... > x(x-1)(x-2)(x-3)... But I can't figure out a way to show that x! grows faster than x2 or 2x. I know it grows faster since I can compare the graphs of...

Homework Statement Estimate the minimum proton lifetime from the fact that you haven't yet died from internal radiation. Use the following conditions: 1.) At a dosis of Dmax = 2 Greys per year (Jkg-1 yr-1) you would already be dead. 2.) The human body is made mostly of water. 3.) The total...

From the standpoint of temperature (not pressure), would components that could experience fission experience a higher fission rate toward the center of the Earth because of the higher temperature, or at ordinary room temperature conditions?

Hi, I have a small gardening project and am trying to decide what kind of pump I need in order to maintain 50 psi (344.7 kPa) inside the line. The line is a 0.170 inch inner diameter vinyl tube with mister nozzles every few inches, for a total of 2 feet. This is a volume of about 9 cm^3. I...

oops I meant "Rate of change of area of a square with respect to its side length" Ok I have to use this annoying Stewart textbook for my Calc class in college. Most of the questions require what I like to call "Monkey Math," where you just memorize a set of steps and then follow them rigidly...

Good Morning Sirs, it seems to be surprisingly hard to get the numbers of a mystery: How fast expand hot rocket exhaust gases into empty space? Of course aside from its exit velocity! Does the expansion interfere with the impulse direction? I.e. is the impulse omnidirectional effective...

For example... wind turbines are primarily listed by their wattage (1.5MW etc.) Presumably their output is varied according to rotational speed, so I'm guessing that the rating is simply a guide. However, for a given mass, at a given height; due to standard gravity, can we state that this...

Homework Statement [10] The air pressure in an automobile's spare tire was initially 3000 millibar. Unfortunately, the tire had a slow leak. After 10 days the pressure in the tire had declined to 2800 millibar. If P(t) is the air pressure in the tire at time t,then P(t) satises the di...