Growth Definition and 327 Threads

Homework Statement At the beginning of the Gold Rush, the population of Coyote Gulch, Arizona was 365. From then on, the population would have grown by a factor of e each year, except for the high rate of "accidental" death, amounting to one victim per day among every 100 citizens. By solving...

Homework Statement The count in a bacteria culture was 900 after 15 minutes and 1400 after 30 minutes. What was the initial size of the culture? What is the doubling period? What is the size after 70 minutes? When will the population reach 11000? Homework Equations P0= 900/e15k=1400/e30k...

Hi, I am explaining the function of each parameter in my model: a*bcx Are these correct? I said that as a changes the graph is stretched parallel to the y axis. The movement takes place when we change b and c but I said the growth is exponential... Is that the correct term...

Homework Statement Here is the equation I am given. I'm supposed to find the carrying capacity. dp/dt=.05P-6.6666667e-5P^2 I know the general solution is rp-rp^2/k with k=carrying capacity, but the addition of the middle term has thrown me off. The Attempt at a Solution I tried...

Fairly straightforward. How did you, as a person[i.e, your personal characteristics; your own little quirks], end up where you are now? When you were much younger, what kind of child were you? What about your teenage years and then your adult life? I think that this might be a pretty...

Everyone knows that education is important for economic growth, but does anyone have any ideas how much the government should use to rise the knowledge level(not necessary in dollars but maybe in how much free/cheep education) and if there are educations they should encourage more than others?

I have been thing about this, seems logical in a way, most reactions increase with concentration surface area, temperature and catalysts. Some of the factors are listed here:- http://library.thinkquest.org/12497/factors.htm They seem pretty similar to the one I put in the answers to my...

hi all, i am looking to build an ultrasound producing device that emits at 50,000 cps? i need a list of materials and how to construct the circuit. research shows that you can multiply the growth of plants (radishes were tested) by 150% if subjected to ultrsound at around 50,000 cps. thank you...

Why do economies need to grow? If a country has a narrow social inequality, a high GDP/capita, why does that country's economy need to keep growing? And isn't that insustentable? Do we have the resources necessary to keep increasing the production of goods every year?

Are the two following hypothetical observations contradictory according to GR? 1. Particles fall towards a black hole but never cross the event horizon 2. After observing this for a few million years, the mass of the black hole is observed to have grown over that few million years. Or...

Homework Statement In 1996 the total energy used in the world was 400 million terajoules = 400 exajoules (EJ)= 4 x 10^20J . Projections for energy use vary, but generally it is expected that between 20 and 30TW will be needed by 2025. (a) What percentage growth in energy consumption on an...

Homework Statement In a nanocrystalline material the grains grow from d0 = 5nm to d = 10nm over a period of t = 1h. The temperature is 500K and the material constant is k0 = 1/s. Homework Equations http://en.wikipedia.org/wiki/Grain_growth#Ideal_grain_growth The Attempt at a...

Help needed with crack growth simulation in Ansys implementing CZM Hello, everyone! Could you, please, help me with the following issue? I’m trying to simulate a crack growth in an anisotropic media using cohesive zone model (CZM), and the results I get do not agree with my expectations...

So I recently took a job in R&D right out of my Master's program (in electrical engineering). When I was interviewing at the company, I quickly realized that everyone was "Dr. so-and-so". I actually did not interview with a single person that did not have a PhD out of 8 people (except for the...

Hi I am reall stuck on this question. company A has invested in a new machine The company has decided that for the next two years that it will reinvest all its earnings from other company products into rolling out the new product. Earnings per share were $2 in the past year and have been...

Homework Statement Water is pumped into a tank. Volume V, is kept constant by continuos flow. The amount of salt S, depends on the amount of water that ahs been pumped in, call it X. ds/dx = -S/V Find the amount of water needed to eliminate 50% of the salt. Take v AS 10,000 gallons...

I am curious to what extent black hole growth can be used to probe understanding of various particles/fields. 1] Dark matter: Let's consider dark matter to be so weakly interacting we can model it as a perfectly non-interacting gas. For even more simplification, let's assume dark matter...

Hi! I am amateur in mathemathicals growth models but I am doing my graduated work in adjust five differents models in some growth parameters in onion, [PLAIN]http://img820.imageshack.us/img820/2929/models.png So my doubt is basically in a derivate for gauss model, i can't derivate this model...

Hi, this contracted company that I am working with has this data. Basically they collect the number of transactions each day. Then they graph these transactions out by Week, always monday - sunday. The data is then stored in a table where the x-axis is the date of the monday the week started...

This topic emerged in another thread but I find it interesting enough to warrant a new thread of its own. The premise is that GDP growth provides more money for investment, consumption, and other spending. To the extent that this extra money allows fiscal discipline to relax, it can have the...

Homework Statement Leaking oil is forming a circular patch on the surface of the sea. The area of the patch is increasing at a rate of 250 square metres per hour. Find the rate at which the radius of the patch is increasing at the instant when the area of the patch is 1900 square metres...

Hi, I am trying to understand how one can derive the lattice growth formula of L (n) = n^2 ( n + 1)^2 / 4 I looked at 2x2 and 3x3 matrices and could count the squares and rectangles in the figure. L (2) = 9, L (3) =36 and so on. However, I am more interested in finding out...

Why is the emf induced in an inductor much larger when the switch connecting it to a battery is closed than when the switch is opened? Somewhere in a text I had read that di/dt is very large when an LR circuit breaks but then its value for growth and decay in an LR circuit is...

Homework Statement A colony of bacteria is grown under ideal conditions in a laboratory so that the population increases exponentially with time. At the end of 3 hours there are 10,000 bacteria. At the end of 5 hours there are 40,000. How many bacteria were present initially? Homework...

hi, I am confused about how the vapor pressure affects the materials growth. Can someone comment on the following : If the vapor pressure of a precursor, let's say N, is high then it will be hard to grow a material containing N because it will be hard to incorporate it onto the substrate...

Homework Statement If there is a quantity T comprised of two other quantities such that T=L+B, and quantity T and B are both increasing in every period at a fixed percent such that %growth T > %growth B, it will be true that %growth L > %growth T. It will also be true that as n approaches...

My group is doing a research project for our technical writing class :/ We are studying carbon nanotube production, and are going to say super growth CVD would be the best production method for this company. Would super growth CVD produce usable nanotubes for electrical circuits, batteries, and...

I have a project in my grade 11 biology class to design a controlled experiment showing how some factor affects plant growth, specifically radishes. I have decided to add urea as a nitrogen fertilizer to one group and do nothing to the other leaving all other factors the same between the two...

Homework Statement How at a cellular level does salt concentration affect the growth? Homework Equations The Attempt at a Solution -sodium ions stimulate the growth -stabilise the cell membrane -affect Na-dependent active transport/motility Could you give me a bit more info for...

Hello I am currently researching on crystals and how their growth rate is affected by magnetic fields for my upcoming lab. Most of the information is based on labs but I quite don't understand what they speak of. So I was wondering if anyone here has any nice reading material on crystals and...

Hi I was just wondering if anyone could please tell me what Australians desired trade balance growth rate is Per year of GDP (macroeconomic policies)? is trade aimed at a target of 3 % of GDP? i know inflation = 2-3% GDP = 3% but cannot find trade? Any help would be really...

Homework Statement A Czochralski growth process is begun by inserting 1000 moles of pure silicon and 0.01 mole of pure arsenic in a crucible. For this boule, the maximum permissible doping concentration is 1018 cm-3. What fraction (X) of the boule is usable? (k=0.3) Homework Equations...

Homework Statement Homework Equations <see above>The Attempt at a Solution I'm a bit unsure how to set this up to solve for a solution. Any advice? Its obviously a separable differential equation. But I'm unsure what it is I'm looking for. This looks different then some population...

Say we take a carrot... or steak (or whatever food you fancy) and put it in a sealed container along with a culture of 'normal' bacteria (I'm talking about the regular bacteria that would be present to decompose food). Now, here comes the question: What would be the most effective way to stop...

For the period from 1900 to 1980, calculate the log base e (ln) of the world population values and plot these values on the vertical axis against the year on the horiontal axis. Draw the best straight line you can through these points and determine its slope, k. What is the exponential...

Can someone please describe the different growth strategies that plants use in dark and light, and explain why these are important at different stages of growth in natural environments.

I've had some arguments after I assumed ( perhaps wrongly) that electric fields were responsible for the direction that branches grow in. In any case my inquires on this all result in the same answers. That the direction of growth is determined by light and gravity. Do all you agree with...

Homework Statement Homework Equations The mark scheme is 2, 2, 3, 3 For a) ii), it's a sequence of integers up to the floor of n2/2 The Attempt at a Solution We haven't done growth rates of sequences, only of equations. a) i) looks like the growth rate would be 5n, but I...

Sorry if this is the wrong section (already posted it in the biology forum and got no response) but this question comes from a convo I had with some friends the other night.. Say you were able to grow a full size tree indoors (assuming you had the space, nessesary lighting, soil, etc..) and...

Hello, for continuous compouding (in the exponential growth and decay) the function for interest after t years is: A(t) = A0*e^rt A0 should be read A at time 0 in the book, they say when you differentiate this function this is what you get dA/dt = r*A0*e^rt = rA(t) I don't see...

What do you put in diary if you write one, how often you write and where do you store it? I have been using a personal (private) google blogger for past 2 years where I am writing how I am growing and overcoming my weaknesses.

Homework Statement The population of the world was 5.7 billion people in 1995 and 6.2 billion in 2008. Assuming exponential growth by what year will the population reach 11 billion? The Attempt at a Solution i started by trying to find R but am not sure the my way is right...

Homework Statement As long as N isn't too small, the growth of cancerous tumors can be modeled by the Gompertz equation, dN/dt=-rN*ln(N/K), where N(t) is proportional to the number of cells in the tumor, and r, K > 0 are parameters. (a) Sketch the graph f(N)=-rn*ln(N/k) verses N...

Homework Statement Consider a population whose number we denote by P . Suppose that b is the average number of births per capita per year andd is the average number of deaths per capita per year. Then the rate of change of the population is given by the following differential equation...

let be the integral equation h(x)= \int_{0}^{\infty} \frac{dy}{y}K(y/x)f(y) here the kernel is always a positive , then if h(x)=O(x^{a}) and the integral \int_{0}^{\infty} \frac{dy}{y}K(y)y^{a} exists and is a positive real number then also f(x)= O(x^{a})

There are "quasicrystals" with fivefold symmetry in the crystal diffraction pattern. They're aperiodic in a systematic way, similar to Penrose tiles, which tile the plane in a five-ish way. The pattern doesn't have translational symmetry, but you can get the pattern to correspond as closely as...

Homework Statement To encourage buyers to place 100-unit orders, your firm's sales department applies a continuous discount that makes the unit price a function p(x) of the number of units x ordered. The discount decreases the price at a rate of $0.01 per unit ordered. The price per unit for a...

Catastrophic event" stopped growth of galaxy{ON News} Growth of the galaxy stopped,it exploded does this may effect our galaxy http://uk.news.yahoo.com/4/20100311/twl-catastrophic-event-stopped-growth-of-41f21e0.html

dS/dt = kS - W How do I solve this problem if k is the growth constant and W is also constant? Here is what I have so far, but I don't think its quite right: dS/dt = kS - W (kS - W)-1dS = 1dt 1/k*ln(kS - W) = t + C ln(kS - W) = kt + C1 kS - W = C2ekt S = (C2ekt + W) / k...

Homework Statement A cell of some bacteria divides into two cells every 40 minutes. The initial population is 2 bacteria. a)Find the size of the population after t hours b) Find the size of the population after 6 hours. c) When will the population reach 12? Homework Equations...