Growth Definition and 327 Threads

Nail growth hormone? Hello Don't actually know if this is the correct section but anyway. Does anybody know how our fingernails grow? What stimulates them to grow? Is there something i could do more/take to help my nails grown quicker and stronger? Thanks _Muddy_

Yet another interesting anomaly: http://seattlepi.nwsource.com/local/357096_beaks31.html?source=mypi

I know this hormone can be dangerous and that using it isn't going to extend your life or anything...but can it affect height? Theoretically is there a way it could be used to grow a few inches, if so how much and in what way? (In someone in their 20s as opposed to someone in their teens) If not...

The number of bacteria in a lab is model by the function M that satisfies the logistic differential equation dM/dt = 0.6M (1 - (M/200) ), where t is the time in days and M(0) = 50. What is the limit of M(t) as t approach infinity? Do i use the fundamental theorem of calculus?

This is from a website on the effect of the moon on life on earth: "By counting the growth rings in 400-million-year-old coral fossils and in 3-billion-year-old stromatolites, geologists calculate that Earth was rotating four times faster when it formed than it is today". They could see...

I seriously need all the help I can get because I don't understand these last two questions of this essay, I got everything else figured out and done except for the two at the bottom. Details; "A scientist designed the following experiment to test the limits of cell population growth. Cells...

[SOLVED] Century Growth Problem: Rate of Change 1. Problem: Because Earth's rotation is gradually slowing, the length of each day increases: The day at the end of 1.0 century is 1.0 ms longer than the day at the start of the century. In 27 centuries, what is the total (in hours) of the daily...

Homework Statement In a model for the growth of a population,p_n is the number of individuals in the population at the end of n years. Initially, the population consists of 1000 individuals. In each year, the population increases by 20% and on Dec.31st, 100 individuals leave the population...

a bacterial population B is known to have a rate of growth proportional to B itself. if between noon and 2 PM the population triples, at what time, no controls exerted should B become 100 times what it was at noon? what does it mean by between noon and 2pm? does it mean that it takes 2hrs...

If all I have given is that 1. Bacteria grows at a rate proportional to it's size. 2. It doubles in 2 days. 3. At 10 days, population is 1000. I'm not given the initial bacteria count, I need help setting up the equation. I did: dy/dt = ky => dy/y = kdt => lny= kt + c =>...

I found this in a textbook about how to promote particle growth. I'm not really sure what it is talking about: To promote particle growth: " add precipitant slowly with vigorous mixing to prevent local, highly supersaturated condition where the stream of precipitant first enter the...

Homework Statement A roast turkey is taken from an oven when its temperature has reached 185 degrees F and is placed on a table in a room where the temperature is 75 degrees F. When will the turkey have cooled to 100 degrees F? Homework Equations dT/dt=k(T-Ts) where Ts=temperature of...

The logistic growth model is the following: dx/dt=rx(1-x/K), with r and K and as constants, and x is a function of t. I'm really not sure where to begin. First I tried separation of variables, but that didn't work out (and I don't even know if I was doing it right). Should I even be...

Malthus' principle of population growth can be written as the differential equation y'=ky where y(t) is the population t years after the initial measurement and k is the growth constant. The solution to this differential equation is given by y(t)=Ae^{kt} where A is the initial...

Homework Statement A bacterial population size N is known to be growing exponentially. If the population triples between noon and 2pm, at what time will N be 100 times the noon population. Homework Equations Firstly. Is this a distribution function?? If so; f(t)=ue^ut where E(t) = 1/u...

I'm looking for an additive I can add to latex paint that will prevent mold and mildew from growing on it. Xylenol comes to mind, but I'm not sure. Or maybe a small amount of benzylkonium cloride. It of course has to have low toxicity, yet be effective on mold. This is part of my...

:frown::frown: Homework Statement Suggest reasons for each ofd the following observations: a.When transplanting a small plant from a pot to the garden, it is importanat to dig it up carrfully, leaving the roots in a ball of soil. If this is not done the plant may wilt after it has been...

I'm in Calc II for the summer, but for some reason my teacher gave us a take-home test on exponential growth. She said we could work together and such, but the class didn't have time, so I was wondering if somebody could check it for me. It seems pretty straight to me, but it's a large chunk...

Can anyone tell me how to calculate population growth. my book doesn't tell me how to do that. is the formula rN=dN/dt

Asphalt potholes seem to have a self-fufillment to maximize their size. They tend to start in the most trafficked areas of a road so that avoiding them risks crossing the double yellow line into oncoming cars, or ramming the curb. Striking one increases its width, breadth and depth...

Homework Statement The number of rabbits in a colony is given by N=80e^(0.02t) where t is in days. c) After how many days will there be 500 rabbits? N=500 A=80 k=0.02 t=? Homework Equations (ln being the exponential logarithm) Q=Ae^kt and possibly the conversion formula: ln y =...

The Problem: Consider a species in which no individuals live beyond 3 years. Divide the population into four age groups labelled by n = 0,1,2 and 3. Assume that only the second and third groups can reproduce. For each group n let bn denote the birthrate and d_n the death rate. Find a matrix A...

Is it possible for a human to have an abnormally fast growth of brain size and development leading to a fully grown adult brain before say age 15 or even 10? If so are there cases like this and what happened to them? Is this how child prodigee comes about? Or is child prodigee usually good at a...

hey, I've always wondered this and couldn't find an answer for it: 1) suppose you're a person who works out, and then you stop. how long does it take for your muscles to go "back to normal." and does this deterioration begin as soon as muscle repair after the workout has stopped (24-36 hours...

i was just wondering abt this thing for a while... the total no. of human beings are increasing over the decades...which means some %ge of the Earth's matter is getting converted in the form of humans...suppose if the population goes on increasing, then theoretically there should be only humans...

So I've been given a differential equation that models bacterial growth, p(t), and the concentration of critical substance, q(t), whatever that's suppose to mean. I've solved both of these and found that: q(t) = q_0 e^{vt} Where q0 is the amount critical substance at t=0. v is a constant. I...

The initial mass of a species of fish in a lake is 7 million tonnes. The mass of fish, if left alone, would increase at a rate proportional to the mass, with a proportionality constant of 2/year. However, commercial fishing removes fish mass at a constant rate of 15 million tonnes per year...

I'm a bit confused about exp growth and exp distribution. Suppose I have a branching process situation, where there are n individuals in generation 0, and each individual produces a random number of offspring, according to some distribution (say Poisson), at each generation. Now, then after a...

I need some help with some statistics stuff. Right now I need it to understand one particular discussion in a poker forum, but I also think that this is a good opportunity for me to learn these things better. That's why I'm posting my questions here instead of in the poker forum. Someone...

http://www.fiscalpolicy.org/FPISmallBusinessMinWage.pdf

A common inhabitant of human intestines is the bacterium Escherichia coli. A cell of this bacterium in a nutrient-broth medium divides into two cells every 20 minutes. The initial population of a culture is 90 cells. the question asks to find the relative growth rate, if we measure t in...

the question is how do I solve (1.024)^t=2.857 and find "t" without using logarithms

In 1980, there were about 170 million vehicles (cars and trucks) and about 227 million people in the United States. The number of vehicles has been growing at 4% a year, while the population has been growing at 1% a year. When was there, on average, one vehicle per person? hmm, I think...

im trying to solve a population growth problem. not sure if I am using the right eqn. Please check: Q: if the population doubles in two years, how long does it take to triple? Solution: general equation for population growth: N=No*e^(rt) 1) find unknown constant "r" from given...

\sum_{p\leq N}\frac{1}{p}=\log\log N + A + O(\frac{1}{\log N}) Does it mean that we can simply replace the O part with a function that is a constant times 1/(log N)? What would be the difference between A + O(\frac{1}{\log N}) and O(1)?

Hi, I need a help on an school assignment. I'm suppost to be doing a presentation about the Growth of IT Architecture, managing it, and the kinds of problem it causes. Anyone have any ideas that I can talk about or any resources would be appreciated thanks!

Hi, I don't know what I am doing wrong in this problem: In 1980 the world population was approximately 4.5 billion and in the year 2000 it was approximately 6 billion. Assume that the world population at each time t increases at a rate proprtional to the population at time t. Measure t in...

I am quite sure the first approach is to use partial fractions but I am unclear how to finish this equation 1/P*dP/dt=b+aP

This seem to be a contraversial issue but does lifting weights during the early teenage years or just before puberty like 14, stunt growth? I am talking about often but normal weight training like 1 hour sessions for 5-6 times a week and with relatively normal weights although on the heavy...

Suppose we have an observer at a large distance from the event horizon of a black hole, pouring matter towards the BH at some constant rate of m per second. Will he see the BH's radius increasing at a rate of 2Gm/c^2 per second, or does gravitational time dilation change the apparent growth rate...

I have f(x,y,z)=(x^2)y-x(e^z) and point Po=(2,-1,pi) I need to find a) gradient at point Po ( done) b) Rate of change of f at point Po in the direction of vector u=i-2j+k (it's also done) c) Unit vector in the direction of fastest growth of f at Po. I can't find formulas for a last on...

I understand why base e can be used when the percent growth per annum is 100%, but I don't understand how it can be justified that the growth for numbers other than 1 can be put into the exponent.

Hey, here is a question I couldn't figure out. I think it's actually really easy, but the wording confuses me. A recent survey showed that the population, P, of Victoria is growing at an annual rate of 1.1%. Let P0 represent the population on January 1, 2001 and let t represent the time, in...

Uranium Tiles and tobacco plant growth Someone told me a few years back that tobacco industries have used uranium tiles to help grow tobacco plants. I wasn't sure about this so I decided to throw the topic at my biology professor in case he knew something I didn't. I don't know if this is...

Why does the hair on our bodies (much like the hair on animals) grow to a certain point, then fall out/stop, but the hair on our heads seems to grow indefinately? Do any other wild animals have hair that can grow forever? I'm not only interested in why it grows in physical terms, but...

I know hair grows from skin, and about 0.5-1.5 inchs long. do u no any way to stop hair growning. any way that is not harmfull or has side effects now and forever. -------------------- Ok, truthly, I have lot os hair on my body, and it seems like growing more and more. I just want to waer...

Experiment to show how algal growth effects plants

Hello I am having major difficulties with two Differential equation. 1. If I have the equation P=2000/(1+9e^.06t). where p=population and t=time. How do I work out when the population is growing the fastest? To work this question out do I just make t the subject and diff twice and let it...

Can anyone here explain to me the role of auxin in cell's elongation? :confused: I think it's related to the acid growth hypothesis,but i need the explanation on how this hypothesis works. :rolleyes: thanks a lot for anyone who help :smile: o:)

A work of an spanish applied mathematician, Antonio Brú, has caused a shock here. Spain has a large tradition in the fight against Cancer, and has great sciencists working in this topic. Take a look at this article: http://www.biophysj.org/cgi/content/full/85/5/2948 (The Biophysical...