Science & Mathematics - 4 November 2007

If, for some particular angle θ, sin θ < 0 and cos θ > 0, in what quadrant must θ lie? What is the sign of tan θ?

2007-11-04 06:52:45 · 2 answers · asked by Brick Top 1 in Mathematics

The mass of water needed to fill a different flask is 194.93 g. The density of water at various temperatures is listed in Appendix D of your laboratory manual. If the temperature is 23.0 deg. C, what is the volume of the flask in liters?
L

2007-11-04 06:45:11 · 1 answers · asked by Heather L 1 in Chemistry

2007-11-04 06:43:54 · 7 answers · asked by ian02766 1 in Mathematics

A plane took 3 hours 15 minutes to return to Spain.
The length of this journey was 2350km.
Calculate the average speed of the plane ins

1. Kilometres per hour,
2350/3.25 = 723
(how come it's 3.25?)

2007-11-04 06:43:09 · 6 answers · asked by Anonymous in Mathematics

i would appreciate it if you would tell me how u got the number in a simple way as possible. thanks!
also, this is from a pre-calc honors class

2007-11-04 06:38:16 · 2 answers · asked by Pinkie09 1 in Mathematics

I need to prove that

(1+secx)/(sinx +tanx) = csc x

and that

(1-cosx)/(cosx) = (tan^2 x)/(secx + 1)

These are the only two that I have left and I cannot figure them out! If you could please help me that would be great. Thanks!

2007-11-04 06:36:35 · 3 answers · asked by Anonymous in Mathematics

i already know that they are
just like.. how so?
i know they use less energy, but what about their chemistry does this?
Like, i'm talking about specifics, like electrons and atoms and how all that works to make it efficient

2007-11-04 06:35:39 · 2 answers · asked by Anonymous in Physics

If there is an equation available that would be great!

2007-11-04 06:34:10 · 6 answers · asked by Anonymous in Mathematics

why is there a doppler effect when the source of sound is staionary and the listener is in motion? in which direction should the listener move to hear a higher frequency? a lower frequency?

2007-11-04 06:32:43 · 3 answers · asked by michael l 1 in Physics

2007-11-04 06:30:57 · 3 answers · asked by Jeff R 1 in Mathematics

Actually Was it yesterday? Cause the Clocks were changed by my husband and I was just curious

2007-11-04 06:28:45 · 16 answers · asked by Anonymous in Geography

2007-11-04 06:26:38 · 3 answers · asked by Anonymous in Mathematics

Hi,
I have gathered 5 botanical samples for a project. I need to identify these leaves.
Is there a site where i can look for pictures of leaves with their respective names?

thanks

2007-11-04 06:26:02 · 2 answers · asked by toodles_1399 1 in Botany

2007-11-04 06:25:00 · 3 answers · asked by Anonymous in Mathematics

Here is the problem: http://i20.tinypic.com/316vui9.jpg
a. 0°
b. 45°, 135°
c. 90°
d. 0°, 90°
Thanks for the help!

2007-11-04 06:20:59 · 1 answers · asked by sillyboys_trucksare4girls 2 in Mathematics

Find the distance between (–3, –2) and (1, 4). Express your answer in simplified radical form.

2007-11-04 06:19:20 · 2 answers · asked by meme 1 in Mathematics

so in science we had 2 fish tanks, one with plants and one with out, so what i need to know was how one had nitrogen and the other didn't, im very confused. We took pH, ammonia, nitrite and nitrate data, which is supposed to be included in our responce.

2007-11-04 06:17:51 · 2 answers · asked by Anonymous in Botany

I don't have any personal opinion on this question, but it has been at the back of my mind for some time: how long do you have to wait once you have given blood, until you can donate again?

My dad has been donating for years and he says that sixteen weeks is the absolute minumum as blood replenishes quickly.

However, I heard somewhere else that you have to wait 15 years. I find this a bit unbelievable, but what is the exact waiting time, and does it differ around the globe? Is there any set minumum number of weeks/months/years worldwide?

2007-11-04 06:14:29 · 10 answers · asked by Anonymous in Medicine

This question goes to Paul B: Are you talking about chromatography's physical principle?

2007-11-04 06:12:06 · 1 answers · asked by Anonymous in Chemistry

2007-11-04 06:12:02 · 6 answers · asked by jacks_insanity 3 in Zoology

2007-11-04 06:10:50 · 3 answers · asked by ? 1 in Weather

2007-11-04 06:07:03 · 10 answers · asked by musicman 1 in Astronomy & Space

Can anyone help me to evaluate the limit using Hopital's Rule of [ (e^(2x) + e^(-2x) - 2) / 1-cos(pi x) ] as x approaches 0

please show work

2007-11-04 06:06:41 · 3 answers · asked by Michael 1 in Mathematics

When looking at the physics behind the spinning of clothes in a washer, i know that the clothes are separated from the water and thus the water is not separated from the clothes. But WHY? I need a good explanation, possibly relating to centripetal acceleration or uniform circular motion. (I know that other answers were since the clothes are heavier, they are separated first, but this is not an accurate explanation as determined by my teacher). Thanks for your time.

2007-11-04 06:04:17 · 2 answers · asked by M4tr!x 2 in Physics

2007-11-04 06:02:09 · 16 answers · asked by RAYMOND A 1 in Astronomy & Space

-there is a bus with 7 Girls
-each girl carries 7 bags
-inside each bag there is 7 cats
-every cat has 7 kittens
-all cats have 4 legs each

how many legs are in the bus?

2007-11-04 05:59:20 · 12 answers · asked by Jackie 1 in Mathematics

2007-11-04 05:57:53 · 7 answers · asked by Daniela M 1 in Physics

i'm having a lot of trouble graphing this!
i know the vertex is (10, 1) since it follow the y=a|x-h| +k formula but i dont know how to find two other points to use to make my graph.
when i tried substituting to find the y intercept i got this :
y= 2 | 2 x 0 + 10| +1
y = 2 |10| +1
y= 21
is this right?
if so, when i tried substituting to find what y would be if the x=6, i got y= 45.
this doesnt make sense when i grpah it because my graph goes up then down.
can someone explain to me how to find two points?

2007-11-04 05:56:20 · 3 answers · asked by ♥ 2 in Mathematics

2007-11-04 05:55:28 · 4 answers · asked by haj a 1 in Mathematics

for values near a, provided that the following 3 conditions are satisfied.
f(a)=p(a)
f'(a)=p"(a)
f"(a)=p"(a)
A.) For values of x near a=0, find a quadratic polynomial, p(x)=Ax^2+Bx+C, that is a quadratic approximation of the function f(x)=e^-x^2
B.) Use the function p to approximate the value of f at x=1/2 and x=2

2007-11-04 05:54:49 · 1 answers · asked by nickesha t 2 in Mathematics