Science & Mathematics - 18 December 2007

What are the only organisms that can make carbohydrates? Through which process are they produced?

2007-12-18 16:14:33 · 4 answers · asked by Anonymous in Botany

Find the fundamental frequency and the frequency of the first three overtones of a pipe 45 cm long

a) if the pipe is open at both ends
b) if the pipe is closed at one end. Use v=344m/s
c) For each of the above cases, what is the number of the highest harmonic that may be heard by a person who can hear frequencies from 20Hz to 20,000 Hz

2007-12-18 16:11:01 · 1 answers · asked by Anonymous in Physics

This is a calculus problem. Please help me because I am trying for two days and couln't solve this problem.

First Order Chemical Reactions, In some chemical reactions the rate at which the amount of a substance changed with time is proportional to the amount present. For the change of glucono lactone into gluconic acid, for example,
(dy/dt) = -0.6y
when y is measured in grams and t is measured in hours. If there are 100 grams of a glucono lactone present when t = 0, how many grams will be left after the first hour?

2007-12-18 16:10:51 · 3 answers · asked by Anonymous in Mathematics

Let's say I want to divide a rope 100 meters long into 25 parts. Each part must have a unique length but the sum of all parts must still be 100 meters.
2 cases are of interest to me:
case 1: i dont care to know or set the size of any parts as long as they sum up to 100 meters and the rate of change should not change from one part to the next (linear?).
case 2: I want to be able to set the size of the biggest part AND the size of the smallest part, both these 2 parts together should not be more than 50 meters or half the total of 100 meters and all the 25 parts together should of course still sum up to 100 meters. In this case the solution should not be linear.
It seems to me reminiscent of some financial formula like npv but I can't figure it out. Help!

2007-12-18 16:10:45 · 1 answers · asked by publicvoidpjr 1 in Mathematics

Directions: Write the factored form of each expression.

1. -xy + 21 + 7x -15

2. -3(x)squared - (y)squared z + (x)squared z + 3(y)squared


yeahh I suck at math haha but please help.

thank you

2007-12-18 16:09:58 · 1 answers · asked by Anonymous in Mathematics

From the genetics point of view ?

2007-12-18 16:08:09 · 3 answers · asked by chanljkk 7 in Zoology

The craters of the moon, solid planets and solar system satellites, are perfectly circular indicating that they are the result of head on (perpendicular) impacts with wandering asteroids. Since the gravitational force of those bodies is not infinite, one should expect that tangential encounters are also possible, the kind that would merely glance at the surface and leave in its wake elongated trails on it. Yet it seems that there are no traces of such slanted contacts. Why?

2007-12-18 16:05:57 · 6 answers · asked by Buho 1 in Astronomy & Space

y=-5x^2-8x+2

2007-12-18 16:05:53 · 2 answers · asked by shatterpulse 1 in Mathematics

for some reason I feel other peoples emotion very strongly through body language and eye contact, I know its normal to a degree, but with me it can be very intense.

2007-12-18 16:03:40 · 10 answers · asked by spacedmanspif 5 in Paranormal Phenomena

whast the purpose of it. i mean, besides seeing how they are smiliar. good answers please, casue im not really sure.
whats done in a pig dissection as well?

2007-12-18 15:58:39 · 7 answers · asked by TheDarkness 1 in Biology

First, your sequence is: 1, 1, 5, 13, 25, 41, 61

Take the differences between adjacent terms:0, 4, 8, 12, 16, 20

Take the difference again: 4, 4, ,4 ,4, 4

Notice that all the second differences are the same. This means the polynomial will be second order so the sequence must look like:

a*n^2 + b*n + c

Now its a matter of solving for a, b, and c. If you call this last difference (here its 4) k and your highest exponent m (here that is 2) then a = k/m!

To get the next coefficient (b) subtract a*n^2 from each term so the terms become:

1 - 2*1^2 = -1
1 - 2*2^2 = -7

You don't need to do the whole sequence, you only need to do one term more than the exponent you are trying to solve for. you get -6, -6, -6, -6, etc.
Using the formula for coefficients above b = -6/1! = -6

So the sequence formula so far is 2*n^2 - 6*n + c

To find c, just evaluate for n=1: 2*1^2 - 6*1 + c = 1
So: c=5
---------------------------------
why is difference -6 not 6? why is formula for c equal to 1?

2007-12-18 15:55:46 · 4 answers · asked by Anonymous in Mathematics

Find the measure of each angle in the polygon.
Thanks :]

http://i11.tinypic.com/8ebl0cg.jpg

2007-12-18 15:55:09 · 6 answers · asked by Anonymous in Mathematics

2007-12-18 15:49:46 · 4 answers · asked by Anonymous in Biology

how are fermentation and cellular respiration similar..whats the main difference between their starting compound?

2007-12-18 15:47:49 · 1 answers · asked by scrub 2 in Biology

I have been assured that the roots x=-1 and x=-2 are both extraneous.. and I reason has been explained to me, but I can't wrap my brains around it. When I check the roots by substituting them back into the original equation
sqrt(1) = -1 and sqrt(4) = -2
they appear to be true statements. HELP!

2007-12-18 15:41:57 · 3 answers · asked by Anonymous in Mathematics

2007-12-18 15:41:10 · 14 answers · asked by c 2 in Astronomy & Space

2007-12-18 15:40:16 · 2 answers · asked by Anonymous in Physics

In triangle ABC, AB = 14, BC = 15, and AC = 13. A square is inscribed in triangle ABC with one side on AB. What is the length of the side of the square?

2007-12-18 15:38:46 · 5 answers · asked by yu.s@att.net 2 in Mathematics

1. 27^x / 9^(2x-1) = 3^(x+4) answer= -1

2. 8^1/4 * (1/4)^x/2 = 16^3/4 answer is-9/4

i tried both of these and well I am unsure where to begin as i tried getting the bases the same and reducing as well following all the exponent rules but can't geet these answers Please Help me!

2007-12-18 15:36:11 · 4 answers · asked by Anonymous in Mathematics

spacifically :)

2007-12-18 15:34:11 · 2 answers · asked by ♥♪ü 4 in Other - Science

2007-12-18 15:33:47 · 4 answers · asked by monk33y 1 in Biology

What is up with the blonde lady who won't shut her fat yapper? How can you find any ghosts if this walking megaphone is always scaring them away with her constant piehole yakkety yakkety yakkety?

2007-12-18 15:32:36 · 9 answers · asked by Anonymous in Paranormal Phenomena

1.
2.
3.

3 things!!
thanks!!

2007-12-18 15:32:05 · 5 answers · asked by Anonymous in Botany

20,15,10

2007-12-18 15:31:41 · 8 answers · asked by Anonymous in Mathematics

2007-12-18 15:31:37 · 16 answers · asked by T-Roy 1 in Astronomy & Space

42. A liquid (p = 1.65 g/cm^3) flows through two horizontal sections of tubing joined end to end. In the first section the
cross-sectional area is 10.0 cm^2, the flow speed is 275 cm/ s. and the pressure is 1.20 * 10^5 Pa. In the second section
the cross-sectional area is 2.50 cm^2. Calculate the smaller section's (a) flow speed and (b) pressure.

43. A hypodermic syringe contains a medicine with the den-SM sity of water. The barrel of the svringe has a cross-sectional
area of 2.50 X 1O^-5 m^2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force F of
magnitude 2.00 N is exerted on the plunger, making medicine squirt from the needle. Determine the medicine's flow speed
through the needle. Assume that the pressure in the needle remains equal to 1.00 atm and that the syringe is horizontal.

44. When a person inhales, air moves down the bronchus (windpipe) at 15 cm/s. The average flow speed of the air
doubles through a constriction in the bronchus. Assuming incompressible flow, determine the pressure drop in the
constriction.

2007-12-18 15:30:47 · 1 answers · asked by Jonny C 2 in Physics

a gas weighing 22.40 g occupies a 10.00-l flask a 27C and 722 torr of pressure. What is the molar mass of the gas?

2007-12-18 15:29:19 · 5 answers · asked by ngurl 2 in Chemistry

A farmer wants to build a rectangular fence. 3 sides will be made out of cement and cost $10/feet. 1 side will be made out of bricks and will cost $30/ feet. The area is to be 20 ft^2. Minimize the cost.

2007-12-18 15:25:40 · 3 answers · asked by Quest 1 in Mathematics

Metallic cobalt crystallizes in a hexagonal close-packed structure.

2007-12-18 15:24:11 · 2 answers · asked by Jonathan 2 in Chemistry

Ok, I've been doing this homework for hours and still don't fully understand it. I have this problem, 4m-n=6 and I have to solve for n. I got it down to -n= 6/4m. what do I do with the -n?? Divide both sides by one perhaps? Plz help.

2007-12-18 15:23:26 · 6 answers · asked by Anonymous in Mathematics