Science & Mathematics - 26 September 2007

we have a kind of room heater which is a combination of storage, radiant and convection. My question is - does it take the same amount of electricity to heat the ceramic core from cold to 10 degrees as it does to heat it from 10 to 20 degrees? I suppose I am asking whether the heating effort is in a straight line or a curve. I know there is a unit Kelvin or whatever which is supposed to be constant but does it vay depending on the material being heated and the temperature it has reached so far?

2007-09-26 20:01:29 · 2 answers · asked by XT rider 7 in Physics

As i write i can see two beautiful rainbows in the sky, both actually very strong in colour, but one question that has bugged me for years, why is the second rainbow, and often the third one too, always in reverse colour order. I know that rainbows are made by the suns light scattering through the raindrops, like light through thousands of prisms, but why are the colours reversed??

2007-09-26 19:51:08 · 6 answers · asked by Katy H 2 in Weather

10x^-2 +33x^-1 -7=0...please sure your work and how you got the answer..it would be greatly appreciated

2007-09-26 19:50:27 · 4 answers · asked by Anonymous in Mathematics

Have you heard that there is a very destructive storm cell heading to the coast from the sw. Check out this BOM site:

http://mirror.bom.gov.au/products/IDR664.loop.shtml?looping=1&reloaded=0&roads=true&topography=true&locations=true&range=true#skip

2007-09-26 19:47:05 · 5 answers · asked by chrisviolet4011 4 in Weather

--->Amtrak's 20th century limited is en route from chicago to new york at 110 km/h when the engineer spots a cow on the track. The train brakes to a halt in 1.2 min, stopping just in front of the cow.

(a) what is the magnitude of the trains (constant) acceleration? (b) what is the direction of the acc?
(c) how far was the train from the cow when the engineer first applied the brakes

&

-->an objects is moving initially in the x direction at 4.5 m/s^2 when an acceleration is applied in the y direction for a period of 18 seconds. if the object moves equal distances in the x and y directions during this time, what is the magnitude of the acceleration?

2007-09-26 19:46:09 · 1 answers · asked by Tommy 2 in Physics

(8x^2 - 5x + 1/sq rt 8) / (x-2) (x^2 + 4)

i've tried substitution but got stuck. any help would be great. thank you.

2007-09-26 19:45:46 · 2 answers · asked by Maddie 1 in Mathematics

If so than where is the missing link? IN Africa?

2007-09-26 19:31:43 · 10 answers · asked by Anonymous in Biology

2007-09-26 19:14:16 · 4 answers · asked by Anonymous in Chemistry

which variable is it?

2007-09-26 19:08:09 · 2 answers · asked by chazeleyes1410 1 in Biology

http://www.flickr.com/photos/ukaaa/1302620236/in/set-72157600233851176/

2007-09-26 19:06:50 · 5 answers · asked by infraviolet 2 in Zoology

what do you believe will happen on december 23rd 2012 do you believe it will be the end of the worl

2007-09-26 19:05:50 · 15 answers · asked by Anonymous in Astronomy & Space

I know that I have them, but I want them to be more intense and useful for myself and others. So, what can I do for myself to really hone in on the Psychic and Clairvoyant abilities that I know that I possess? Thank You.


Please don't respond with something like: "You're Psychic, you should already know". I'm being serious.

2007-09-26 19:05:31 · 17 answers · asked by Ohteech 2 in Parapsychology

I need to know k, if I had one I could figure it out, but I'm trying to figure it out before hand.

2007-09-26 19:05:26 · 1 answers · asked by badaerozepstones 3 in Physics

2007-09-26 18:47:41 · 7 answers · asked by wlalng... 1 in Biology

2007-09-26 18:46:04 · 1 answers · asked by wlalng... 1 in Other - Science

but not the rest of their music? (Although, I'd prefer to hear NONE of their music.)

2007-09-26 18:42:38 · 3 answers · asked by Anonymous in Other - Science

P4(s) + 6 Cl2(g) --> 4 PCl3(l)
If the reaction proceeds in 65% yield, how many grams of P4 are required if 137.5 grams of PCl3 are desired?

2007-09-26 18:37:16 · 3 answers · asked by tyler8x6 2 in Chemistry

Antibiotics is a chemical that kills a particular cell, by blocking cell production. Viruses are not cells. This is why you can't get rid of a cold.

Viruses invade one cell which produce a strand of DNA then codes for the production of more viral RNA (retroviruses) producing new viruses and eventually killing the cell and organism. There are about 10 trillion cells in the human body.

So how do you cure a virus?

2007-09-26 18:35:33 · 7 answers · asked by Anonymous in Medicine

All input is greatly appreciated!! =)

2007-09-26 18:35:18 · 2 answers · asked by tu b 1 in Biology

2007-09-26 18:34:44 · 3 answers · asked by Susie 6 in Chemistry

2007-09-26 18:33:00 · 4 answers · asked by Anonymous in Biology

step by step how do i get this answer i cant do fraction ones or i dont know how to right now

2007-09-26 18:30:54 · 10 answers · asked by danny s 1 in Mathematics

Can anyone tell me the correct equation thats something like X= Xo + Vt + 1/2at^2 or something like that?

2007-09-26 18:25:54 · 3 answers · asked by Anonymous in Physics

I remember learning, once, an equation that related the index of refraction of a substance to the wavelength of the light entering. Index of refraction as a function of wavelength. I have a degree in physics, but I only have a vague memory of this. Please help.

2007-09-26 18:21:58 · 4 answers · asked by Michael S 2 in Physics

i have few questions...

1. If f(x) = x / cot(x) , then f' ( Pi / 4 ) =?
( this problem... i jsut dont get it....)

2. F(x) = G[x + G(x)] , howd you find F'(x) of this??

3. What is the fourth derivative of F(x) = (2x-3) ^ 4
( im not sure if this is 24(2^3) or 24(2^4))

thx

2007-09-26 18:20:05 · 3 answers · asked by Anonymous in Mathematics

i want to see if i did this right.
3square root(2x^2+4)
X=(1/2)
the answer is 7 right?

2007-09-26 18:15:36 · 2 answers · asked by Anonymous in Mathematics

as a traffic light turns green, a waiting car starts with a constant acceleration of 6.0m/s^2. At the instant the car begins to accelerate , a truck with a constant velocity of 21m/s passes in the next lne(hint/: set the two distance equations equal to each other)
plz ansdwer step by step and show the work then you will get 10 free pts thx
a. how far will the car travel before it overtakes the truck
b how fast will the car be traveling when it overatakes the truck?
2. a stone falls freely from rest for 8.0s.
a. calculate the stone's velocity after 8.0s
b what is the stones displacement during this time?
3. a student drops a rock from a bridge to the water 12.0m below with what speed does the rock strick the water?

thank you for solving th is hard question to me

2007-09-26 18:14:52 · 1 answers · asked by Anonymous in Physics

i need major help
an physist in my life right now would be great
PLEASE
see if you can answer this question-

i will be dropping an egg on my teachers head while on top of a tower thats 8.52 meters
my teacher will be on the bottom and walking towards the tower from 4 meters away
my teachers steps are 57.48 cm long and shell walk at a rate of 100 steps per minute
my teacher is 1.62 meters tall
ive already calculated that its going to take my teacher 4.175 seconds to reach the tower from her 4 meter away starting point
i need to find out at what time i should drop the egg so that it will land on my teachers head right when she reaches the end of the 4 meter point
PLEASE help
me
and if possible
tell me how u got the answer

2007-09-26 18:13:03 · 2 answers · asked by Anonymous in Physics

as a traffic light turns green, a waiting car starts with a constant acceleration of 6.0m/s^2. At the instant the car begins to accelerate , a truck with a constant velocity of 21m/s passes in the next lne(hint/: set the two distance equations equal to each other)
plz ansdwer step by step and show the work then you will get 10 free pts thx
a. how far will the car travel before it overtakes the truck
b how fast will the car be traveling when it overatakes the truck?
2. a stone falls freely from rest for 8.0s.
a. calculate the stone's velocity after 8.0s
b what is the stones displacement during this time?
3. a student drops a rock from a bridge to the water 12.0m below with what speed does the rock strick the water?

2007-09-26 18:12:56 · 2 answers · asked by Anonymous in Physics

In a triangle, the smallest angle is 36 degrees less than half the largest angle. The middle angle is 60 degrees more than the smallest angle. What is the measure of the largest angle?

2007-09-26 18:01:44 · 4 answers · asked by DoWHATiDO 3 in Mathematics