Science & Mathematics - 26 November 2007

a) give an equation for the line L⊥, perpendicular to L, through P.

b) Where does L⊥ meet L?

2007-11-26 08:10:48 · 3 answers · asked by lexcollect 1 in Mathematics

I understand about calories expended versus calories taken in. I have seen all the charts that tell you how many calories are burned in a wide variety of activities...from housework, to yardwork, to dancing, climbing stairs, etc.

What I'm trying to find out is HOW are these calculations done? Is there someone with a clipboard measuring calories expended during sex to establish that standard? And if so how is he measuring it? Off-the-wall example, I know...but that's what I'm trying to learn.

Thanks.

2007-11-26 08:09:31 · 3 answers · asked by kathy_is_a_nurse 7 in Biology

most cactuses have spines, which are leaves modified to protect the plant. the spines cover juicy stem that stores water. explain how cactus leaves and stems might have changed through the process of natural selection.

2007-11-26 08:09:01 · 5 answers · asked by Anonymous in Biology

most cactuses have spines, which are leaves modified to protect the plant. the spines cover juicy stem that stores water. explain how cactus leaves and stems might have changed through the process of natural selection.

2007-11-26 08:07:20 · 7 answers · asked by Anonymous in Botany

2007-11-26 08:02:44 · 1 answers · asked by Daniel F 1 in Chemistry

is anyone doesnt know GCF means greatest common factor

2007-11-26 08:00:40 · 3 answers · asked by RiSSYDOLL<3 2 in Mathematics

So, I need to know the general way to find the ground state energy, but I've provided an example problem so you know what I'm asking.

You have a cold gas of atoms, and you observe that if you shine light consisting of photons with energy 6 eV or greater through the gas, some free electons are observed, implying that photons of such energies are able to ionize an atom in the gas (that is, separate an electron from an atom). You find that with photons of less than 6.0 eV, no ionization occurs.

What is the energy of the ground state? K+U=?

So I really really need to know this for the exam, and I somehow missed it. If anyone could please give an explanation (the answer is -6 eV), I would be very very appreciative. :-D

2007-11-26 07:58:34 · 2 answers · asked by Anonymous in Physics

Can you help me explain this question to a friend?

A quarter is flipped and one number is drawn from a box containing the numbers 2,4,6,8,10.

What is the probability of getting a tails or the numbers 6 or 10?

2007-11-26 07:56:03 · 5 answers · asked by B H 3 in Mathematics

If so, then how can we keep time travel a secret, for example, if I met my father in 1969 on the day he graduated high school?

2007-11-26 07:55:23 · 3 answers · asked by Yahoo Man 1 in Physics

The big bang theory bugs me, how can it be used as an explination to how the universe was created.

how the hell did the ball of gas get there? if there was no universe then where the hell was it. ahhhhhhh someone shoot me quick to stop the pain.

2007-11-26 07:52:54 · 21 answers · asked by hoppo_2000uk 3 in Astronomy & Space

1 5/6+2/7
2. 8/9-5/12
3. 2m/3-4n/5

2007-11-26 07:52:20 · 3 answers · asked by lisa g 1 in Mathematics

2007-11-26 07:50:06 · 1 answers · asked by Anonymous in Botany

I have a question that askes:
A bird population is going extinct exponentially. 5 years ago there were 1400 birds, now there are 1000. Using A=Aoe^tk when will the population hit 100?
If someone could set up the formula for me I could solve it, I just don't know where to start.
Thanks

2007-11-26 07:48:44 · 5 answers · asked by Happy Killa Pants 2 in Mathematics

2007-11-26 07:48:32 · 4 answers · asked by crazynood_sweet14 1 in Mathematics

Please its urgent my assignments due in wednesday and i have looked everywhere for this conversion and can't find it. I need it to work out the mole.

2007-11-26 07:48:21 · 4 answers · asked by Anonymous in Chemistry

2007-11-26 07:44:49 · 1 answers · asked by tai 1 in Mathematics

(a) Calculate the gravitational potential energy of a 2 kg mass on the surface of the Earth.
J
(b) Calculate the gravitational potential energy at an altitude of 22 km.
J
(c) Take the difference between the results for parts (b) and (a), and then compare this with mgh, where h = 22 km.
J (difference between parts a and b)
J (mgh)

2007-11-26 07:42:18 · 2 answers · asked by Amber G 2 in Physics

Find the orbital speed of a satellite in a circular orbit 2640 km above the surface of the Earth.
km/s

2007-11-26 07:40:40 · 1 answers · asked by Amber G 2 in Physics

(a) Find the distance from the center of the Earth at which a 10.0 kg object has a weight of 7.0 N.
m
(b) If the object is released at this location and allowed to fall toward the Earth, what is its initial acceleration?
m/s

2007-11-26 07:40:11 · 1 answers · asked by Amber G 2 in Physics

1/4 of Mr.Rabbit supporters do not bother to vote.
All of Mrs.Hare supporters vote, but the probabilty that those voters will punch the correct chad is only 2/3.

Who will win the election?

2007-11-26 07:36:40 · 2 answers · asked by Alexander 6 in Mathematics

12. Haley and Lindsy disagree about the answer to another problem that Mrs. Johnson assigned. Haley says that (c^2+c)/(c^2) can’t be simplified. Lindsy says that it simplifies to c.

What do you think?

A Haley is right because nothing cancels.
B Lindsy is right because c^2 cancels.
C They’re both right. Either answer is acceptable.
D They’re both wrong. The correct answer is (c+1)/(c)
E They’re both wrong. The correct answer is (2c)/(c^2)

2007-11-26 07:32:46 · 10 answers · asked by Anonymous in Mathematics

what is the negative square root of negative 9?
a. 3
b. -3
c. 3i
d. -3i

2007-11-26 07:32:08 · 7 answers · asked by Anonymous in Mathematics

What is the energy (in J/particle) of ultraviolet radiation that has a wavelength of 2.278 x 10 ^-2 micrometers?
The speed of light is 3.00 x 10^8 m/s.

Please show the steps or explain so I will understand how to do this. Thanks

2007-11-26 07:31:46 · 1 answers · asked by Anonymous in Chemistry

2007-11-26 07:30:15 · 2 answers · asked by crazynood_sweet14 1 in Mathematics

Or when we read about it or talk about it or anything?

2007-11-26 07:29:55 · 3 answers · asked by Anonymous in Biology

Once a massive star runs out of hydrogen, it fuses into helium (it uses helium as energy), helium fuses into carbon . . . etc. What is the last element that a star can fuse into and why?

2007-11-26 07:28:18 · 25 answers · asked by bbmm 4 in Astronomy & Space

2007-11-26 07:25:35 · 3 answers · asked by M B 1 in Medicine

1/2 hour before noon volumes 2 and 3 of encyclopedia were added to the shelf, and volume 1 was removed.

1/4 hour before noon volumes 4,5,6,7 of encyclopedia were added to the shelf, and volume 2 was removed.

1/8 hour before noon volumes 8,9,10,11, 12,13,14,15 of encyclopedia were added to the shelf, and volume 3 was removed.

each time when time remainig was halved, twice as many new volumes were added and 1 next volume removed.

How many volumes reamian on the shelf at 12:01 pm?

2007-11-26 07:21:50 · 6 answers · asked by Alexander 6 in Mathematics

I have donated blood by transfusion approx 5 times, for getting
a cup of orange juice for it, but when my father has got hemorrhoidal cancer, from the radiations his blood faded out pink, and he died without they giving him a drop of blood by
transfusion.
How would you take that?

2007-11-26 07:19:07 · 6 answers · asked by Anonymous in Medicine

2007-11-26 07:17:05 · 1 answers · asked by Gideon 1 in Chemistry