Science & Mathematics - 17 November 2007

i have a lab report to submit on monday a.m. it's incomplete help find the definition of compressive strength of concrete and the factors affecting it.

2007-11-17 12:27:37 · 0 answers · asked by brownsand_2007 1 in Engineering

2007-11-17 12:27:12 · 4 answers · asked by iryL15 1 in Biology

2007-11-17 12:24:56 · 8 answers · asked by Anonymous in Mathematics

...which has (more or less) equal contributions by equally educated advocates of Creationism\Intelligent design and Modern Evolution Theory respectively? All the websites I can find have a definite view they espouse, and while I'm sure this is valuable in its own right, it isn't very helpful to me.

What I'm thinking of is an academic site in an open discussion format with formal rebuttals et aliae eiusdem generis, open to editing only by specialists with at least an MA, and a forum for questions from laymen.

2007-11-17 12:22:19 · 2 answers · asked by delsydebothom 4 in Earth Sciences & Geology

1. x^2-8x+16=0
2. 3u^2=-4u+15
3. 2x^2=200
4. 4(t+6)^2=160


please and thank u

2007-11-17 12:18:54 · 3 answers · asked by Anonymous in Mathematics

2007-11-17 12:18:23 · 7 answers · asked by ♥me 1 in Mathematics

a ridgid 8.2L flask contains a mixture of 2.5 moles of h2 , .5 mol of O2 and sufficent Ar so that the partial pressure of Ar in the flask is 2.00 atm. the temp is 127 C.

a. calculate the total pressure in the flask
b. calculate mole fraction of H2 in the flask
c. calculate density ( in g L-1) of the mixture in the flask

the mixture in the gas is ignited by a spark, and the reaction represented below occurs untill ne of the reactants is completly comsumed.

2H2 (g) +O2 (g) ----> 2H2O(g)

d. give the mole fraction of all species present in the flask at the end of the reaction.


i get the total pressure i just dont know how to do mole fraction.

2007-11-17 12:15:14 · 2 answers · asked by Help?? 2 in Chemistry

x^2+10x+24

2007-11-17 12:11:22 · 9 answers · asked by Chrisso 2 in Mathematics

3. You have a laser with wavelength = 635.3[nm]. The grating has a slit spacing of 1.633E-03[mm]. What is the angle measured for n=1?
angle = _____________________[radian]
Use three sig. figs.; or use N/A, if not enough information is given.

please help and explain this ,thanks

2007-11-17 12:10:33 · 2 answers · asked by Anonymous in Physics

You have a laser with wavelength (λ) 640 nm. You shine it through a diffraction grating of 400 lines per millimeter. You measure the distance to a screen to be 20.3 cm. You measure the second dot in millimeters from the center dot.
What is the wavelength of the laser light?
__________________[nanometer].
Use three significant figure or N/A if not enough information is given.

2007-11-17 12:08:16 · 1 answers · asked by Anonymous in Physics

Because of a higher moisture content, air is a better conductor of charge in the summer than in the winter. Would you expect the shocks from the static electricity to be more severe in the summer or winter? Explain.

2007-11-17 11:59:38 · 4 answers · asked by Jennifer N 1 in Physics

Tarzan and Jane, whose total mass is 137 kg, start their swing on a 4.6 m. long vine when the vine is at an angle 32.6 degrees with the horizontal. At the bottom of the arc, Jane, whose mass is 47 kg, releases the vine. Acceleration of gravity is 9.81 m/s^2. What is the maximum height at which Tarzan can land on a branch after her swing continues? (Hint: Treat Tarzan's and Jane's energies as separate quantities.) Answer in units of m.

Thank you very much for your help in advance!

2007-11-17 11:56:45 · 3 answers · asked by Anonymous in Physics

Given the two functions f and h such that f(x)=x^3 -4x^2+x+6 and h(x)= f(X)/(x-3) , for x is not equal 3 and P, for x=3
A) Find all zeros of the function f
B) Find the value of p so that the function h is continuous at x=3.

This is a tough problem, I couldn't find the zeros, I did many way to simplify it to find the zeros but nothing worked so anyone know how to do it, plz help me
C) Using the value of p found in (B), determine whether h is an even function.

2007-11-17 11:56:38 · 5 answers · asked by Kim M 2 in Mathematics

i see many that create disease and non beneficial effects such as an extra arm.

2007-11-17 11:56:21 · 8 answers · asked by Joe 4 in Biology

gas fuel....uses in the periodic table of elements

2007-11-17 11:48:11 · 3 answers · asked by honeyjoe 1 in Chemistry

A 9.3 kg block is dropped onto a spring of spring constant 1086 N/m from a height of 800 cm. When the block is momentarily at rest, the spring has been compressed by 50 cm. Find the speed of the block when the compression of the spring is 10 cm. The acceleration of gravity is 9.81 m/s^2. Answer in units of m/s.

2007-11-17 11:47:48 · 1 answers · asked by grouchy187 2 in Physics

well, usually.
you're supposed to just remember what they're for?

2007-11-17 11:44:17 · 11 answers · asked by plasticbag 2 in Medicine

What is "The answer to 2+2 times 10?"

This is not my homework but like i said first one to get it right gets Best answer! It is an easy was to get Best Answer

2007-11-17 11:42:55 · 13 answers · asked by Anonymous in Mathematics

2007-11-17 11:33:05 · 14 answers · asked by Jiovanni G 1 in Physics

I sure hope so.

2007-11-17 11:31:26 · 4 answers · asked by ? 6 in Other - Science

My boyfriend has been feeling nauseous, off and on, for the last three months; and every doctor we've gone to has told us there's nothing wrong with him. His blood pressure is a little high, but other than that, there don't seem to be any other symptoms. His blood tests have all come back with normal results.

Sometimes he wakes up with the nausea, and it lasts through the day; other times its triggered by eating seemingly benign foods, like plain pasta or tortilla chips; at one point reading brought it on, but that does not seems to be a problem anymore.

He also feels slightly tired- though not overwhelmingly- most days, but again there was nothing on the blood tests to indicate why this was the case either.

2007-11-17 11:28:21 · 6 answers · asked by Anonymous in Medicine

A large object previously floating on the surface of an ocean is caused to sink. Does it always sink to the bottom or might it find a depth in the ocean where it can float once again?

2007-11-17 11:28:10 · 13 answers · asked by Grant V 1 in Physics

http://img240.imageshack.us/img240/4206/711segmentsinacircle2ri5.jpg

2007-11-17 11:27:12 · 3 answers · asked by Anonymous in Mathematics

I wanted to build a diverse systematic reading list, and I don't have a science background (more english / humanities) but would like to develop this area of my knowledge--are there any books you would suggest that I get started on?

2007-11-17 11:26:09 · 6 answers · asked by Todd 7 in Other - Science

2. A flight attendant pulls her 70 N flight bag a distance of 253 m along a level airport floor at a constant velocity. The force she exerts is 40 N at an angle of 52 above the horizontal. Find the following:
a. The work she does on the flight bag
b. The work done by the force of friction on the flight bag
c. The coefficient of kinetic friction between the flight bag and the floor.

Please show work and explain to me how to do it. Thank you.

2007-11-17 11:23:27 · 3 answers · asked by James J 1 in Physics

If I were to construct a fan 5ft in diameter and I wanted that fan to spin at 40 mph how big of an electrical engine would I need, or rather how many rpms' would it take to acheive that speed?

2007-11-17 11:18:59 · 4 answers · asked by Andrew 3 in Engineering

2007-11-17 11:18:18 · 5 answers · asked by Anonymous in Mathematics

I inherited a farm and I don't know what to do about the animals on the farm, saying it better I don't know how to take care of them. He has 1 milking cow. Does this cow need shots? How often does this cow need to be checked? How often do you milk it? Is the milk good? He has laying hens and the same questions apply. He has a huge garden I don't know what to do. My mom wants us to move in the house, because it is in better shape than ours, I don't know what to do about the animals. My husband says we can make money off of the cow and the eggs, but I don't know

2007-11-17 11:17:43 · 11 answers · asked by Anonymous in Agriculture

I need to find an equation in the form H(x,y) = c that satisfies given trajectories

For example:
dx/dt = 2y , dy/dt = 8x
For these trajectories I can do dy/dx = 8x/2y and use separation of variables to obtain: 4x^2 - y^2 = c

But for the trajectories
dx/dt = x^2 - x + y , dy/dt = y - 2xy
are not separable, so how can I find H(x,y)

2007-11-17 11:14:22 · 3 answers · asked by Anonymous in Mathematics

2007-11-17 11:12:16 · 3 answers · asked by Twin girls due 8/2/09 3 in Biology