Science & Mathematics - 12 October 2007

At night the air smells so much fresher, whether you are in the countryside or in an urban area. For this reason I find it easier to breathe, and jog at night. I can jog for a long time at night, but I'm terrible at jogging during the day.

Why does the air seem fresher at night?

2007-10-12 01:40:33 · 7 answers · asked by Anonymous in Other - Science

CAn someone explain 'how we determine the maximum and minimum points using the second derivative of a function?
I wanna know how the whole thing works..like how the negative value of the 2nd derivative gives the maximum value.
Pleeaassee help me out with this!!

2007-10-12 01:31:42 · 3 answers · asked by meeta1704 2 in Mathematics

I know that graphite is molecule that conducts electricity becuase it has free electrons. However, I found that there are only 7 electrons in every graphite's outermost shell . Everything in nature need 8 electrons in their outermost shell to be stable. Isn't it? Who can help me to explain it by the principle of valence shell. Thanks.

2007-10-12 01:31:41 · 1 answers · asked by Anonymous in Chemistry

A Lufthansa A320 accelerates from rest to liftoff speed of 72.8 m/s in 28.3 s. Each of the plane's two jet engines provides a forward force (thrust) of 111 kN.

(a) What is the mass of the plane?
kg
(b) How far does it travel down the runway before liftoff?
m

part a I got 1.1326e4 kg and part b is 1030.1m. part I solved mult times and all of the solutions I got are wrong, but part b is correct. any ideas on how to find the mass of the engine? thanks!

2007-10-12 01:31:19 · 2 answers · asked by Anonymous in Physics

NaNo is here, RF could be the alternative? (beam me-up, spock)

2007-10-12 01:27:53 · 3 answers · asked by Anonymous in Physics

2007-10-12 01:24:31 · 7 answers · asked by ramkishore 1 in Geography

?

Also

A roast weighs 7 3/4 lb. In roasting, it loses 1/10 �of its weight. How� many servings are in the roast if each serving is 7/32 lb.? Round your answer to a whole number.
29
31.5
29.75
32


A fluid ounce of water weighs 29.57 grams. A fluid ounce of certain oil weighs 65% of a fluid ounce of water. What is the weight of 1 quart of this oil? (Hint: One quart = 32 ounces)
1,022.35 grams
615.056 grams
977.044 grams
514.78 grams


thanks =]

2007-10-12 01:22:05 · 8 answers · asked by Meghan XD 1 in Mathematics

2007-10-12 01:19:36 · 1 answers · asked by Anonymous in Chemistry

2007-10-12 01:17:49 · 8 answers · asked by karthi k 1 in Astronomy & Space

2007-10-12 01:17:14 · 2 answers · asked by Phongthep P 1 in Mathematics

Through the Earths history,on average,have plants evolved faster or slower than animals?

2007-10-12 01:03:16 · 4 answers · asked by ASK A.S. 5 in Biology

Through the Earths history,on average,have plants evolved faster or slower than animals?

2007-10-12 01:02:37 · 5 answers · asked by ASK A.S. 5 in Botany

Do you think that the Human race will evolve further?
>Why/Why not?
>How?
>WHEN?

2007-10-12 01:00:08 · 6 answers · asked by ASK A.S. 5 in Biology

I know it has something to do with disfiguration of the ball and the potential energy, although I dont have a good explanation to why

2007-10-12 00:58:17 · 10 answers · asked by Anonymous in Physics

What do you think would happen if we found that there was life on another planet?What would we do?How would we act?

2007-10-12 00:57:15 · 14 answers · asked by ASK A.S. 5 in Astronomy & Space

2007-10-12 00:47:24 · 5 answers · asked by Anonymous in Weather

I found a comment on my site from somebody who suggested that i should add 'river blindness' disease in parasites section and i did that and i also added an extra page in each other section...i added 'nipah virus', 'streptococcus bacterium', 'tinea cruris' fungus and 'lesch-nyhan syndrome'....check the updated site and tell me what u think of it now plz cuz i need opinions of ppl to make it better..here is it:
www.-biology-.piczo.com

2007-10-12 00:42:16 · 4 answers · asked by Anonymous in Medicine

hey....

I want to know the chemistry behind how a timed release medicine work?

this is for an assignment ... need as much input please ... can anyone help ...

thanks

2007-10-12 00:40:34 · 2 answers · asked by Anonymous in Medicine

2007-10-12 00:29:57 · 8 answers · asked by Anonymous in Medicine

1) v = u + at.

2) S = ut + 1/2 a t^2.

2007-10-12 00:26:30 · 5 answers · asked by Anonymous in Mathematics

Show that d/dx (sin 2x/ 1 + cos 2x) = k/ 1 + cos 2x, stating the value of the constant k.

Ans: k = 2


Show your workings with explanation..thanks

2007-10-12 00:21:02 · 1 answers · asked by Anonymous in Mathematics

Can anyone tell me some various methods and recommendations for a researching a doctor I'm considering for vasectomy operation? Specifically, Dr. Glenn Taylor in Ann Arbor, MI

2007-10-12 00:16:54 · 1 answers · asked by Anonymous in Medicine

Saw this spider in the North Island of New Zealand, I was just wondering if anyone could tell me anything about it?
It seemes to make a hissing noise when the picture was being taken.
Thanks
Pics : http://www.craigferguson.co.uk/holidayPics/NZ%5CSouth%20island%5CWee%20spider%202.jpg
http://www.craigferguson.co.uk/holidayPics/NZ%5CSouth%20island%5CWee%20spider.jpg

2007-10-12 00:12:32 · 5 answers · asked by Lee J 1 in Zoology

Solve for x and express the roots in simplest a+bi form.

4 + (5/x^2) = (6/x)

2007-10-12 00:05:26 · 3 answers · asked by journey 1 in Mathematics

2007-10-12 00:04:43 · 5 answers · asked by Anonymous in Mathematics

A curve has the equation y = (x + 2) √x - 1

(i) Show that dy/dx = kx / √x - 1, where k is a constant, and state the value of k.

Ans: 3/2


Show your workings clearly...I need to understand..thanks.

2007-10-12 00:04:42 · 2 answers · asked by Anonymous in Mathematics

2007-10-12 00:04:14 · 11 answers · asked by Anonymous in Earth Sciences & Geology

2007-10-12 00:00:32 · 2 answers · asked by pobafett 2 in Mathematics