Science & Mathematics - 4 February 2007

The primary method that neuroscientists have used to determine and understand the function of different parts of the brain has been to

---study the anatomy of the brain.
---wait for something to break and see what the effects are.
---use computer modeling to replicate the way the brain works.
---rely on neuroimaging techniques like MRI and CT scans.


I think the right asnwer is ...
rely on neuroimaging techniques like MRI and CT scans.
but I am not sure anyone can verify this?

2007-02-04 12:44:35 · 3 answers · asked by Anonymous in Medicine

Many years ago, I realised that there is a point in the USA where FOUR boundaries meet: Utah, Colorado, New Mexico and Arizona. And recently, I noticed that, within certain states of the USA (e.g. Iowa, Nebraska, Texas), there were many points at which four counties met; in fact, Northern Texas looks a bit like graph paper. But I haven't yet found any place where FIVE boundaries meet at a single point.

2007-02-04 12:44:20 · 3 answers · asked by deedsallan 3 in Geography

I loved math until i reached trigonometry. I have no idea how to simplify or prove identities. Can someone please help me? Here is the problems i need to solve

Prove the Identities:
1. cos²2x-cos² x=sin² x-sin²2x
2. 2sinx cos³ x+2sin³x cos x= sin2x
Write the expression in terms of sin x and cos x only:
3. sin2x+cos3x

Can anyone solve any one of these problems?

2007-02-04 12:42:57 · 4 answers · asked by mikhailb89 1 in Mathematics

2007-02-04 12:41:53 · 5 answers · asked by yungstashack 1 in Earth Sciences & Geology

My reading on my digital ohm meter is 8.9 on the 20K scale, 08.9 on the 200K scale and .008 on the 2M scale. The lower scale, 200 and 2K scales are both 1.---- Do I read it direct as only 8.9 ohms and fail the test requirement of "greater than 500 ohms"

2007-02-04 12:41:44 · 1 answers · asked by Anonymous in Physics

If you take a piece of paper or anything, and fold it or bend it, it becomes thicker. However, if you unravel a DNA molecule it is 3 feet in length. When it is folded in the nucleus it is 1 millionth of an inch. How can that happen?

2007-02-04 12:41:11 · 3 answers · asked by 007 2 in Biology

just curious

2007-02-04 12:40:16 · 9 answers · asked by Justin B 1 in Astronomy & Space

The four 1.0 g spheres shown in the figure are released simultaneously and allowed to move away from each other.

Four charges are placed in the corners of a square, 1cm apart. All 4 charges have a charge of +10nC.

What is the speed of each sphere when they are very far apart?

2007-02-04 12:39:12 · 1 answers · asked by bennyb 1 in Physics

Supposedly, the answer isn't (2x+2y)/(x^2+y^2) which is what I got...
Please explain

2007-02-04 12:38:07 · 2 answers · asked by popngirl_14 2 in Mathematics

why does current start at a maximum and approach zero when discharging, why would the current flow in opposite directions?

2007-02-04 12:38:01 · 4 answers · asked by crazed1511 1 in Engineering

i am having trouble with a physics question which reads as follows:
a block weighing 300N is moved uniformly over a horizontal surface by a force of 60N. Construct the force.
so far what ive done is constructed a rectangular block about 3 inches long and a quarted of an inch wide and on top of this block i drew another block. i dont know how to show it moving uniformly like it says in the question any suggestions...thanks!

2007-02-04 12:35:57 · 1 answers · asked by Fatima 1 in Physics

Question: a defibrilator is used during a hearth attack to restore the heart to its normal beating pattern. A defibrilator passes 18 A of current through the torso of a person in 2.0 milliseconds. (a) How much charge moves during this time? (b) How many electrons pass through the wires connected to the patient?

My Approach:
(a) I = change(q)/ change(time)

18 A = change(q)/ 2.0e-3 s ----- I converted 2.0 ms to seconds

change(q) = .036 C --- answer

(b) .036 C x (1 electron/1.6e-19 C) = 2.3 x 10^8 electrons --- answer

'preciate the help!

2007-02-04 12:34:40 · 2 answers · asked by Anonymous in Physics

why is graphite soft and why does it have a high melting point
and why is diamond hard and also have a high melting point? why is diamond a poor conductor of electric current and graphite a good conductor?

2007-02-04 12:34:22 · 3 answers · asked by cutie pie! 3 in Chemistry

A.
Can make proteins if amino acids are provided in the growth medium.
B.
Can make proteins if mRNA is provided in the growth medium.
C.
Can't make proteins unless aminoacyl synthetase is provided in the growth medium.
D.
Can't make proteins.
E.
None of the above.

2007-02-04 12:33:17 · 4 answers · asked by joseph f 1 in Biology

When dealing with angles you can call them

2007-02-04 12:33:11 · 3 answers · asked by FairestOfThemAll 2 in Mathematics

A stone has a mass of 6.0 x10^-3 kg and is wedged into the tread of an automobile tire, as the drawing shows. The coefficient of static friction between the stone and each side of the tread channel is 0.90. When the tire surface is rotating at a maximum speed of 13 m/s, the stone flies out of the tread. The magnitude FN of the normal force that each side of the tread channel exerts on the stone is 1.8 N. Assume that only static friction supplies the centripetal force, and determine the radius r of the tire.
Well I basically worked till I got this equation r=v^2/usFN
(from r=v^2/usg and v^2=rusFN/m)

so plugging in the numbers I got r=(14.1^2) (6.93x10^-3)/ (.844)(2.44) which r= .289946 but this isn't correct according to the answer key. I really need help on how to work this problem. Thanks in advance.

2007-02-04 12:32:35 · 2 answers · asked by Anonymous in Physics

I don't understand how to graph functions like these and how can I tell how many real zeros there are?

Example: Graph the function: x^3+5

Please explain thoroughly because I have a huge amount of trouble understanding problems like these.

2007-02-04 12:32:20 · 4 answers · asked by Audy 1 in Mathematics

1- Assuming we have a Hardy-Weinberg equilibrium population & the frequency of the dominant allele "B" is 90% & that "b", the recessive allele is the only other allele at this gene locus in the population, what would be the expected frequency of Heterozygous individuals in this population?

2-Why would a female animal prefer to mate w/ a male who is both physically attractive & a good father?

3- List 2 General Structural features that Annelids & Arthropods Share?
-----
1- ?? I don't really understand what I'm doing at all.
p +q= 1
0.9 +0.1= 1.00
B= 90%
b=10%
Is this even close?... PLEASE explain this to me, I'm so Confused!

2- Physically attractive= So that the offspring will have good alleles & so when the time comes, it won't have so much trouble finding a mate?
Good father= to proveide protection, & give female comfort & relief? Does that explain WHY though?

3- ?

Please Help Me. I would really appreciate it! Thank You so Much! = )

2007-02-04 12:31:52 · 2 answers · asked by Miss*Curious 5 in Biology

9/11/2001 - if you add 9+11 then you have to follow suite and add 2003, which equals 2021. They are adding 9+11 as whole numbers but then saying that 2001 isnt a whole number and that the zeros some how disappear. But even if that is the case that still equals 21 which would make it 41 all together. If you only add the 2 and the 1 in 2001 then you have to assume that you have to seperate the 1's in 11. Therefor it will equal 14. I do not see anyway to add these numbers to 23 without it being mathematically impossible. Can you?

2007-02-04 12:31:05 · 2 answers · asked by Doug F 3 in Mathematics

completely forgot how to do these =[

can anyone help?

alice cycles to carla's house at 12 mi/h and returns by car at 36 mi/h. if the round trip is 1 hour, how far from carla does alice live?

i got 24 minutes..but i just guessed in how to set up the equation

and also

find four consecutive whole numbers such that the sum of the squares of the first and third is 2 less than 6 times the fourth.

yeahh..i tried this a couple of times and ended up with 12, 13, 14, and 15.
i couldn't really figure out how to set up this one either. if you could help it would be great. thanks!

2007-02-04 12:29:43 · 4 answers · asked by kim 2 in Mathematics

A.
Produces repressible enzymes.
B.
Produces constitutive enzymes.
C.
Produces inducible enzymes.
D.
None of the above.

2007-02-04 12:28:14 · 1 answers · asked by joseph f 1 in Biology

I WAS GOING TO GET A 14 INCH BUT IVE NOT SEEN MANY PEOPLE WHO OWN ONE COMPARED TO THE OTHERS SO I WAS WONDERING IF THE SMALLER ONES WERE BETTER

2007-02-04 12:27:52 · 4 answers · asked by super_man 3 in Astronomy & Space

i have a 99.7 temp for 3 days is that a temperature? or what urgeant!!

2007-02-04 12:27:38 · 8 answers · asked by Anonymous in Weather

Find the arc length from (-3,4) clockwise to (4,3) along the circle
x^(2) + y^(2) = 25. Show that the result is one-fourth the circumference of the circle.

Use the arc length formula!!

2007-02-04 12:25:44 · 3 answers · asked by Anonymous in Mathematics

Your local electric company supplies you 1 k/w (kilowatts) of power for 1 hr. for 8 cents. Assume that you could climb stairs continuously for 1 hr. How much money would this climb be worth?

2007-02-04 12:22:39 · 1 answers · asked by Sally s 1 in Physics

2. integrate 1 / ((16-x^2)^(3/2)) dx by letting x = 4sin(t)
(integrate fully)

3. integrate 1 / ((x^2)((sqrt(25 + x^2))) dx by letter x = 5tan(t)

4. integrate 1 / (sqrt(8 + 2x - x^2)) dx

5.integrate from x=4 to x=0 1 / (sqrt(324+x^2)) dx

6. integrate from x=5(sqrt(2))/2 to x=0 (sqrt(25-(x^2))) dx

7. integrate 1 / (x^2)(sqrt(144-x^2)) dx

8. integrate (sqrt(16x-x^2)) dx

9. integrate 44 / (sqrt(40 - 6x - x^2)) dx

2007-02-04 12:22:35 · 2 answers · asked by Anonymous in Mathematics

2007-02-04 12:22:22 · 2 answers · asked by datboricuachick585 1 in Mathematics

Here goes:
If a sample of DNA were found to contain 20% of cytosine what percentage og guanine would be in this sample?Why?

2007-02-04 12:22:21 · 6 answers · asked by Anonymous in Botany

To investigate how the intensity of the reflected ray varies with the angle of incidence which the light ray makes with the plane surface of a glass sample.

2007-02-04 12:22:03 · 1 answers · asked by brian_rambadan 2 in Physics

The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus and the template is from a human cell. The DNA synthesized would be most similar to :
A.
Human DNA.
B.
T. aquaticus DNA.
C.
A mixture of human and T. aquaticus DNA.
D.
Human RNA.
E.
T. aquaticus RNA.

2007-02-04 12:19:26 · 3 answers · asked by joseph f 1 in Biology