Science & Mathematics - 6 December 2006

frequencies in a population?

2006-12-06 09:35:43 · 2 answers · asked by totallyclueless 1 in Biology

2006-12-06 09:35:09 · 2 answers · asked by Anonymous in Mathematics

I need to find the integral of T(t) = 20 + 75e^(-t/50) on the interval [0,30]. I've done it two ways and they don't give me consistent answers.

The first way I did it was to evaluate it as two separate integrals (20 and 75e^-t/50). I used substitution on the second integral so that it becomes -75e^u on the interval [0,-3/5]. This method gave me an answer of about 2292.

The second method I tried was to keep the two parts together. So when I did a substitution, it became -20 - 75e^u on the interval [0,-3/5]. This gave me an answer of about 46.

Which method is correct?? Or are both wrong?

2006-12-06 09:34:58 · 2 answers · asked by Jacqueline Sherry 1 in Mathematics

2006-12-06 09:34:47 · 15 answers · asked by CelticMoonGoddess 2 in Mathematics

I wanted to know how to write a shortened electron configuration. If you can help me, that's be greatly appreciated! Thanks!

2006-12-06 09:34:00 · 2 answers · asked by Dana Mulder 4 in Chemistry

in magnesium or iron or aluminium or copper

2006-12-06 09:33:35 · 6 answers · asked by Anonymous in Chemistry

My math teacher said one of the problems has an answer, except the chioces are all wrong. The pattern is this: 1, 4, 9, 16, 25...

Now, I know that each is added by an odd number, and after every number, the odd number goes up to the next one. To do this, I need to know the function in terms of n (for position number), x (for coeficcient of n), y (extra term, like 3n+4, y=4), and z (the number value, like 1, 4, 9, etc.).

This is for extra credit, and I want the points.

2006-12-06 09:31:23 · 8 answers · asked by ZZ 4 in Mathematics

Ive also read that the universe is the shape of a doughnut,how is that "infinite" and if it is getting bigger or smaller whats it getting bigger in

2006-12-06 09:29:16 · 23 answers · asked by pj 3 in Physics

x >(little line under arrow) 1
y <(little line under arrow) 3

2006-12-06 09:28:58 · 1 answers · asked by Anonymous in Mathematics

I don't understand it.

I'm looking at one of my problems and it shows a triangle that has three unequal (in legnth) sides. So that would be a scalene triangle... but it also has a 90º angle. But don't most triangles have that? I can't tell what a right angle is and what isn't.

2006-12-06 09:28:51 · 6 answers · asked by yupp 1 in Mathematics

2006-12-06 09:28:21 · 7 answers · asked by deon xoxo 1 in Astronomy & Space

2006-12-06 09:28:02 · 10 answers · asked by Caitlin L 2 in Mathematics

science homework...
americium or europium?

2006-12-06 09:27:53 · 3 answers · asked by KiKi E 2 in Chemistry

2006-12-06 09:27:07 · 7 answers · asked by lulu 1 in Chemistry

2006-12-06 09:26:37 · 1 answers · asked by katie m 1 in Chemistry

i'm doing my science homework and i need to know if adding salt to water will increase or decrease the freezing point of water. IN other terms will it take longer or shorter to freeze when salt is added. The salt is regular table salt.

2006-12-06 09:26:34 · 5 answers · asked by GirlyGirl 2 in Chemistry

2006-12-06 09:24:25 · 8 answers · asked by Anonymous in Medicine

He throws a stone vertically upwards so that its distance, h m, above the cliff top is given by h=20t-5t^2.

(a) Calculate the time which elapses before the stone hits the beach (it just misses the boy and the cliff on the way down)
(b)Calculate the speed with which the stone hits the beach.

Who can help me with this maths problem?

2006-12-06 09:23:15 · 7 answers · asked by Anonymous in Mathematics

Is it true that only VERY, VERY, VERY rich people such as Bill Gates can afford a new cloning device that if their pet died, they could just get DNA from the old one and clone it to the exact same thing?

2006-12-06 09:21:32 · 14 answers · asked by nycee. 2 in Biology

well im doin a science project and lucky 4 me & my parttner kelsey we got stuck w/ skunk cabbage and a black bear and its due 2 weeks from tommorow and we dont know how to find out the relationship bewtween them them so if any1 can help us plz let me know thx!!!!

2006-12-06 09:18:45 · 4 answers · asked by Michelle A 1 in Zoology

A child riding a bike has a total mass of 40.0 kg the child approaches the top of a hill that is 10 m high and 100m long at 5.0m/s. If the force of friction between the bicycle and the hill is 20N, what is the childs velocity at the bottom of the hill? (Disregard air resistance g= 9.81 m/s^2)

A. 5.0m/s
B. 10.0 m/s
C. 11m/s
D. Child stops before reaching the bottom.





i have already posted this question and thanks to the guy who answered but i need some more answers so i can decided what i'm going to do.

2006-12-06 09:17:29 · 5 answers · asked by strawberrylollipop12345 1 in Physics

Why do oil rigs in the sea have a burning pipe?

2006-12-06 09:16:53 · 4 answers · asked by Anonymous in Earth Sciences & Geology

only reply if your answer is from a tustworthy source. thank you

2006-12-06 09:16:38 · 17 answers · asked by Dany H 1 in Medicine

How practical are these disk generators I've read about?

2006-12-06 09:15:02 · 3 answers · asked by moaistatue 2 in Physics

2xcubed-xsquared+5x-12) divided by (2x-3)

2006-12-06 09:14:33 · 4 answers · asked by Shannon B 1 in Mathematics

2006-12-06 09:14:30 · 4 answers · asked by marquise258 1 in Chemistry

Only answer if your answer is from a reliable and sure source. thank you

2006-12-06 09:14:14 · 18 answers · asked by Dany H 1 in Medicine

2006-12-06 09:13:56 · 4 answers · asked by Aaron B 1 in Zoology

2006-12-06 09:12:10 · 3 answers · asked by Kayla 5 in Botany

Should it deter me from living there?

2006-12-06 09:11:07 · 3 answers · asked by kadagaba 1 in Zoology