Science & Mathematics - 21 December 2006

How do you solve:
(a+b)^2 - (b+c)^2 - (a+c)^2

2006-12-21 09:14:38 · 5 answers · asked by D M 1 in Mathematics

2006-12-21 09:13:07 · 1 answers · asked by Anonymous in Engineering

I have 2 groups, one who received treatment and a control group. About 12 variables were measured in each group. The Treatment group has about 65 subjects, the control group only has 25-30. Is it better (statisticaly speaking) to have the groups as is (65:30) or should I take a random sub-sample of the Treatment group and make it even (30:30)? Seems to me like more=better, but I'm not sure if that is true or not.....

2006-12-21 09:11:48 · 3 answers · asked by gbarnett76 2 in Mathematics

Let's say..one minute you're walking you're dog..and the next minute you're in some UFO...

What the??

2006-12-21 09:09:39 · 15 answers · asked by RUNINTLKT 5 in Astronomy & Space

2006-12-21 09:08:29 · 3 answers · asked by Pushpendra C 1 in Mathematics

I will be very hapy to recieve your answer which will boost me to ask you more questions. thanks &Regards

2006-12-21 09:08:16 · 8 answers · asked by ismail m 1 in Astronomy & Space

During surgery, a patient must have at least 40 mg of an antibiotic in his system. The amount of anitbiotic present in (k) hours after administration of 100 mg of this antibiotic is given by P(k)=100(.508)^k. After how many hours to nearest tenth will the nurse have to give another dose to keep the level of antibiotic high enough?

2006-12-21 09:06:57 · 5 answers · asked by Matt 2 in Mathematics

Everyone seems to think that traveling back in time can't happen.
Why is that? Also, how would you prove it impossible?

2006-12-21 09:06:53 · 25 answers · asked by canofpineapples 1 in Physics

How may arrangements can be made with the letter of the word MATHEMATICS? In how many of them are the vowels together?

2006-12-21 09:06:23 · 3 answers · asked by Pushpendra C 1 in Mathematics

2006-12-21 09:03:38 · 5 answers · asked by Kaylin J 1 in Earth Sciences & Geology

2006-12-21 09:02:14 · 7 answers · asked by Anonymous in Mathematics

"Scientists have now cloned the genes found in the bacteria species Deinococcus that shield it from radiation & through recombinant DNA technology, have placed them in tomato plant cells."

is this possible? if so, how?

2006-12-21 09:01:15 · 2 answers · asked by JoAnna 2 in Biology

2006-12-21 08:56:26 · 9 answers · asked by ♫ 2 in Astronomy & Space

2006-12-21 08:56:22 · 3 answers · asked by redberry 1 in Physics

Serious answers would be nice but I'm expecting too much there! There are more stars in the universe than grains of sand on Earth. This is believed by most boffins. If that is true - surely, we can't be the only one with vehicles on our speck of dust. So that is why I believe in UFO's but never had the luck to witness one.

2006-12-21 08:54:50 · 18 answers · asked by ? 3 in Astronomy & Space

2006-12-21 08:48:39 · 17 answers · asked by Anonymous in Astronomy & Space

if we invent a way to travel to other stars, past the speed of light. how hard would it be to navagate accurately to a distant star or planet, and what would a ship traveling faster than light look like from earth?

2006-12-21 08:47:06 · 9 answers · asked by tibracer 2 in Astronomy & Space

I overheard a discussion the other day posing this question.
If you were traveling at the speed of light while holding a flashlight, would the light from the flashlight be traveling double the speed of light? What do you think?

2006-12-21 08:46:40 · 11 answers · asked by pokeyisaninja 1 in Other - Science

Water and Ammonium Acetate?

2006-12-21 08:45:29 · 5 answers · asked by ♥ 6 in Chemistry

and the square root of 420

2006-12-21 08:43:34 · 9 answers · asked by Anonymous in Mathematics

Say, we are 100,000 light/years away from a hypothetical galaxy that is 100,000 light/years in diameter.
We can see the close edge of this galaxy and the far edge of this galaxy.
Close edge is 100,000 light/years away from us. Far edge is 200,000 light/years away from us.
Since the light takes longer from the far edge to us, the galaxy's geometry shoiuld appear distorted to us?
Instead of seeing spiral arms we should see a soup a stars. Discuss.

2006-12-21 08:41:51 · 6 answers · asked by Roomba 2 in Astronomy & Space

A light detector based on the photoelectric effect is made with cesium metal. Cesium metal has a work function of 3.4 times 10 raised to the -19th J. What is the longest wavelength of light that one could expect to detect with this device?

a) 850 nm
b) 580 nm
c)1700 km
d) 7100 km
e 420 nm

Please show appropriate work. Thanks.

2006-12-21 08:41:49 · 2 answers · asked by Anitec 2 in Chemistry

i'm taking calc ap and i really need help with it were doing word problems and i just dont get it. can anyone help me or at least give me a good link to a help site?

2006-12-21 08:41:21 · 5 answers · asked by tibracer 2 in Mathematics

what neutral substance could be formed from the combination of the H+ ion from the acid and the OH- ion from the base?

2006-12-21 08:35:03 · 6 answers · asked by ♥ 6 in Chemistry

Ok, I know this is stupid but I'm too tired to figure this out:

'After drinking the required volume of Mountain Dew, a student's pulse rate rose from 72 bpm to 110 bpm after 10 minutes. Work out the percentage increase in heart rate.'

I've completely forgotten how to do this, so can someone please explain it?

2006-12-21 08:32:43 · 13 answers · asked by PurpleWatermelon 2 in Mathematics

2006-12-21 08:29:24 · 3 answers · asked by Anonymous in Mathematics

how can i tell if a tringle is right tringle just by looking at the lengths of the legs and hipotanuse. HELP ME PLEASE

2006-12-21 08:29:06 · 11 answers · asked by Anonymous in Mathematics

I am having a huge brainfart because I am having trouble with the calculations of the odds of winning a lottery. The formula for the possible combinations for n numbers in k places is
C(n,k) = n! / (k! (n-k)!)
For some reason I cannot understand why there is a k! in the denominator. I would think it should be:
= n! / (n-k)!
so if n=50 and k=5 then I think it should be
50!/(50-5)! = 254,251,200
but its not, it is
50! / (5! * (50-5)!) = 2,118,760
What the hell am I missing, can somone please explain it to me?

2006-12-21 08:27:51 · 3 answers · asked by E 5 in Mathematics

2006-12-21 08:27:07 · 5 answers · asked by Ibrahim A 1 in Astronomy & Space

and a way was found to colonize it. Would you go ? The travel time could be between 2 to 6 years. Depending on the speed of the shuttle. So,you'd be anesthetized into a hybernation state using squirel hybernating hormone and some Nitrous Oxide.

2006-12-21 08:26:48 · 7 answers · asked by sandwreckoner 4 in Astronomy & Space