Growth Definition and 327 Threads

Hi everyone, I am looking for the correct form of the growth factor in large scale structure. I have found two different equations which I think are not consistent! Can anyone please tell me why it is like this? The first one if from the book "formation of the structure in the universe" Edited...

What factors affect the rate of growth of current when an emf is induced in a coil?

Homework Statement Emily's brother, Jack, is now 105cm tall, having grown by one sixth of his height a year ago. How tall was Jack one year ago? Homework Equations Now my teacher told me to do this: x = 105 - (105/7) x = 105 - 15 x = 90 cm The Attempt at a Solution So 90cm is the answer...

Homework Statement There are initially two cells seen through a microscope. every hour, a computer was tasked with taking a cell count through the microscope. Taking the sum of all the cell counts after the 7th hour, the total cell count was 280 cells. Find the exponential growth rate...

I have a logistic growth problem. I know this because there is an upper limit of approximately 21,000 people. I need to calculate growth rate. Would it be something as simple as taking two populations and dividing them to get the rate (X2-X1/X1) to obtain it or is there an equation I am missing...

First post on these forums, thanks all for your help! Homework Statement It is estimated that the growth rate of the fin whale population (per year) is rx(1 - x/K), where r = 0.08 is the intrinsic growth rate, K = 400,000 is the maximum sustainable population, and x is the current population...

a) On January 1 2000, the park estimated that they had 500 deer on their land. Two years later, they estimated that there were 550 deer on the land. Assume that the number of deer was changing exponentially, i.e. P(t)=ae^bt where P is the number of deer at year t, and a and b are parameters.Find...

When a tree grows even at an angle on a hill side it mostly remains vertical . What is at play here to cause the vertical direction of growth ? Thank you, Pat Hagar

I've always thought that when people say exponential growth, they mean e^x. But other times I hear people just say that the quantity doubles 2^x every time. So which is it? And if it's just doubling, why don't we say that 3^x or 4^x is exponential growth as well, since that's what those...

Homework Statement These questions require you to see a graph - which can be accessed from the link below 43. a). Find the growth factor between the numbers of stick insects in consecutive time intervals of two weeks. Hence find a relationship between ##x## (time in days) and ##y## (number of...

Homework Statement A bacteria culture initially contanis 100 cells and grows at a rate proportional to its size. After an hour the population has increased to 420. a. Find an expression for the number of bacteria after t hours. b. find the number of bacteria after 3 hours c. find the rate of...

Homework Statement A mass of 3 mole gas is heated in a constant pressure of 1.5 atm, expanding from 40 litre to 60 litre. Find the temperature growth. Homework Equations V1/V2=T1/T2. The Attempt at a Solution I thought to write V1/V2=T1/T2. But I don't know T1. The answer is 121 K in my book.

1. The population of a certain country grows according to the formula: N = N0e^kt Where N is the number of people (in millions) after t years, N0 is the initial number of people (in millions) and k = 1/20 ln 5/4. Calculate the doubling time of this population. Leave your answer in terms of ln...

Homework Statement I'm not able to identify this, i found it on my window railings. Could you help me out. Also, they are attached firmly to the railings, i couldn't blow them away, i tried pulling out a few the white parts comes off easily, but the stalk(if i can call it so) is hard to pull...

1. The Problem In the mythical country of Myland, the population recently reached 10 million. At that time, a popular news magazine predicted that with an average yearly growth rate of 2%, the population would be 20 million in 50 years. How does this value (18 million) compare to the value...

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...

Assume that I have absolutely no clue to what is the formula used to generate a sequence. How do I know what kind of formula that is? (Exponential / Linear / Polynomial / etc) Also assume that there is only 1 formula that generates the sequence. I have read somewhere before that: f'(x) ~...

Hi! :o I'm stuck :confused: I was thinking I need to use the equation $f=kw^2$ but I'm really not sure.

Homework Statement If a stock has increased 400% over the last 6 years, then how much does it grow on average per year. Homework Equations 400 = 100(1+r/6)^6 The Attempt at a Solution Divide both sides by 100 4 = (1+(r/6)^6 Take the sixth root of each side. 1.26 = 1 + (r/6) Subtract...

Hello, Do you know the total dissolved particle molarity of fibroblast growth media, and could I achieve to keep the osmotic pressure constant while adding both salt and water to it? (I am assuming the salt does not pass through the cell membrane) Thank you.

Hi All, Having plotted a cell growth curve (fluorescence vs days), I have found that during the lag phase, the fluorescence values decrease. I haven't come across this previously during lectures and can't seem to find any examples online to help explain it. My only thought was that cell death...

Homework Statement The growth of a giraffe population on an island follows a logistical growth model. The maxium giraffe population on the island is estimated at 1000. The population was first measured in 1970 at 125. Then in 1975 the population was 158 a) Find the rate of change in the...

Homework Statement I need to write \begin{align*} N_{k+1} = \frac{\lambda N_{k} }{1+aN_{k} } \end{align*} in the form \begin{align*} N_{k+1} = N_{k} + R(N_{k})N_{k} \end{align*} Homework Equations As above The Attempt at a Solution I know that \begin{align*} N_{k+1} = N_{k} +...

Hey guys, Few more questions for the problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: The first one starts off easy but I found that it gets progress more challenging later on. So the rate of spread should be p'(t) which is: p'(t) =...

Hey guys, I've two more word problem questions this time. Question: So for the first one, I know that y=T-Ts where Ts = 20. Thus, if T(0) = 90, then T'(70) = -1 T'(t) = k (T-Ts) k= -1/50 (via substitution) Now, we must find y. y'(t) = ky and y(t) = T(t) - Ts y(0) = 90- 20 y(0) = 70...

Hey guys, I need help with a few more questions for this problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: For the first one, I took v(t) as 0 since that is when it would be stopping or changing directions. Then I solved for t to get...

Hey guys, Few more questions for the problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: The first one starts off easy but I found that it gets progress more challenging later on. So the rate of spread should be p'(t) which is: p'(t) =...

Hey guys, I have a couple more questions about this problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: For the first one (part a), I went through the steps for logarithmic differentiation by using the ln laws to separate terms, and then...

i suck at these kind of problems #1 Suppose a population grows according to a logistic model with initial population 1000 and carrying capacity 10000. if the population grows to 2500 after one year, what will the population be after another three years.#2 a. make a guess as to the carrying...

[I don't know if this is in the right topic or not so I hope I'm all good] My question is related to the exponential growth and decay formula Q=Ae^(kt). Simply, why is the value e used as the base for the exponent? Does it have to be e? If so, can anybody tell me why? Thanks~| FilupSmith |~

Hi guys, I am not economist, but can anybody tell me whether there is a mathematical model for growth in free market economy without state intervention? Where can I look them up? Thanks.

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)...

I've been wondering about a simple question that I can't just google and get the answer to. Usually when we calculate probability, we know the number of possible outcomes. Say we toss a coin, there are 2 possible outcomes with one being head and one being tail. So the chance of getting a head is...

Homework Statement Consider an item that is initially sold at a market price of $10 per unit. Over time, market forces push the price toward the equilibrium price, $20, at which supply balances demand. After 6 months, the price has increased to $15. the Evans Price Adjustment model says that...

Homework Statement Suppose water leaks out of a barrel at a rate proportional to the square root of the depth of the water. If the level starts at 36 in. and drops to 35 in. after 1 hour, how long will it take for all the water to leak out of the barrel? I have to choose and implement a...

Problem: A tumor may be regarded as a population of multiplying cells. It is found empirically that the "birth rate" of cells in a tumor decreases exponentially with time, so that birth rate is given by B(t)=(B_0)*e^(-a*t) where B_0 and a are constants. Consequently, the governing equation for...

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

Homework Statement Investigate The number of atoms splitting up in a nuclear reaction and Bacterial growth Your investigation should use appropriate formulae and graphs and include information from records of real events. You should aim to show how good the mathematical models are in...

A bacterial population B is known to have a rate of growth proportional to B itself. If between noon and 2pm the population triples, at what time no controls being exerted, should B becomes 100 times? what it was at noon? using this formula $\displaystyle P(t) \;=\;P_oe^{kt}$ please help me...

"...incarceration or institutionalization can delay emotional growth" I once read a criminal profile of a serial killer made by a forensic psychologist. The forensic psychologist wrote the following: "Age is difficult to predict because this analysis is a measure of an offender’s emotional age...

I originally posted this on the Biology message boards. But I have not received any responses. In models of exponential growth, we have an intrinsic growth rate (r) that is calculated as the difference of birth rates to death rates. With the logistic growth model, we also have an intrinsic...

Hi all, I've got this logistic growth problem that I'm unsure of on how to start. I've read though the textbook but it's just not clicking for me; I missed a day of class and don't have a chance to go to office hours, so any help would be much appreciated. I've been given a set of values: time...

Hi all, I've got this logistic growth problem that I'm unsure of on how to start. I missed a day of class and don't have a chance to go to office hours, so any help would be much appreciated. I've been given a set of values: time, population, and change in population. The values are as...

If you don't know anything about this please just read the first 20 lines on the below link and help me understand (I don't know anything either). The vapour liquid solid method: http://en.wikipedia.org/wiki/Vapor%E2%80%93liquid%E2%80%93solid_method uses a solid, liquid and gas phase to grow...

In models of exponential growth, we have an intrinsic growth rate (r) that is calculated as the difference of birth rates to death rates. With the logistic growth model, we also have an intrinsic growth rate (r). How then do birth rates and death rates relate to the intrinsic growth rate in...

Homework Statement There are now about 3300 different human "language families" in the whole world. Assume that all these are derived from a single original language, and that a language family develops into 1.58 language families every 5860 years. About how long ago was the single original...

Homework Statement State whether (e^4-x) + 2 is an exponential growth function or an exponential decay function. Explain why. Homework Equations I want to use the formula f(x) = ae^kx where a>0, and k<0. The Attempt at a Solution I know it is an exponential decay formula...

Hello, I am looking for some help in understanding jet diameter growth due to entrainment. I have an impingement plate positioned approximately 20 cm from the nozzle exit. Is there an equation or information that will allow me to figure out how a free jets diameter grows the further it gets...

Suppose that there is initially x(not) grams of Kool-Aid powder in a glass of water. After 1 minute there are 3 grams remaining and after 3 minutes there is only 1 gram remaining. Find x(not) and the amount of Kool-Aid powder remaining after 5 minutes… So, i set up 2 equations… 3=x(not)e^-k(1)...

αℓєєиα♥'s question at Yahoo! Answers regarding the logistic population growth model Here is the question: I have posted a link there to this topic so the OP can see my work.