Science & Mathematics - 25 September 2007

2007-09-25 15:53:52 · 3 answers · asked by Aquabug222 1 in Mathematics

where do you put cross hairs in convex lenses? and...why can't you put them in concave lenses?

2007-09-25 15:53:43 · 3 answers · asked by Anonymous in Astronomy & Space

Write an expression for each phrase:

Ten times the result of eleven minus two:



The quanitity P minus five eighths time the result of one fourth plus P:

2007-09-25 15:53:18 · 4 answers · asked by Anonymous in Mathematics

How would you explain this and how does it work?

size depends on the priciple quantum number, n .

but when I do the electron configurations, I get different letters and numbers

like Cr: 4s^13d^10

2007-09-25 15:52:48 · 2 answers · asked by Anonymous in Chemistry

so i need the answer to this:

Determine the limit of the function describing the atmospheric pressure on a plane as it descends from 32,000 feet to land at Honolulu, located at sea level. (The atmospheric pressure at sea level is 14.7 lb/in^2).

Dang I hate calculus this is only chapter 1! please give the answer as a limit and show work that you use. THANKS

2007-09-25 15:50:25 · 2 answers · asked by -N- 2 in Mathematics

Do we communicate our emotions through dreams? The next morning I woke up having Irritable Bowel Syndrome. That's how much these negative emotions affected me. Can we sense the sadness distress of others when we are asleep. I don't think my sister is o.k.
Additional Details

0 seconds ago
I feel that I can feel if someone close to me is becoming depressed only when I am half awake and half asleep. The thought of suicide came into my head. Is my subconscious ok or are these the emotions of people in my family?

2007-09-25 15:49:40 · 12 answers · asked by Anonymous in Parapsychology

1) Nicole gets paid $8.25 an hour. She worked 8 hours on Friday. How much did she earn that day?

a. $52.00
b. $59.75
c. $66.00
d. $70.50
_______________________
2) what is the value of this expression?

3(15+9) - 2 x 11 = ?

a. 30
b. 50
c. 572
d. 770

______________
3) Sydney bought 5 new notebooks for $1.35 each and 12 pens that cost 3 for 1.25. What is the total amount she spent, not including Tax, on notebooks and pens?

a. $8.00
b. $10.50
c. $11.35
d. $11.75

________
its cuz i dont really remember when they teached these problems and i dont remember them =[ please help its home work and its due tommorow.

2007-09-25 15:45:55 · 9 answers · asked by Anonymous in Mathematics

Perhaps Osama BinLaden was killed by Americans in Afganistan but they are keeping that a secret and they figured out how to make old videos of him appear new. After he died he was cremated and they spread his ashes all over Afganistan to throw people of the trail.

2007-09-25 15:42:43 · 17 answers · asked by Cowboy C 4 in Paranormal Phenomena

3Cu(s) + 8HNO3(aq) ——> 3Cu(NO3)2(aq) + 2NO(g) + 4H2O(l)

What happens in the above reaction? Why?

(a) Redox (State what is being oxidized and what is being reducted)

(b) Acid-Base

(c) Precipitattion Reaction

2007-09-25 15:42:43 · 3 answers · asked by Anonymous in Chemistry

Please tell me the following:
Age:pre-teen, teen, 20+,or 40+
Country:
Do you believe in global warming? Why/why not?
What are we doing to stop it from happening?
Do you know of any expert opinions on this issue?
What do you know about global warming (even if you don't believe it).
What do you know/have heard is the greatest contributor to the problem?
Thanks

2007-09-25 15:41:11 · 12 answers · asked by mewchic2 2 in Earth Sciences & Geology

2007-09-25 15:41:05 · 6 answers · asked by lindsay.faith 1 in Weather

Calculate the acceleration of a 1700 kg, single-engine airplane just before takeoff when the thrust of its engine is 400 N.

2007-09-25 15:39:55 · 1 answers · asked by Anonymous in Physics

Consider the elements
| 0 -1| = A
| 1 0 |
and

| 0 1 | = B
| -1 -1|

from SL(2, R). How do you find |A|, |B|, and |AB|.
Is this answer surprising?

(A and B are 2x2 matrices)

2007-09-25 15:37:20 · 2 answers · asked by Anonymous in Mathematics

can someone give an example of a stimulus a penguin responds to??

i need an answer ASAP

2007-09-25 15:34:54 · 2 answers · asked by Anonymous in Zoology

Doesn't just have to be on Yahoo Answers. One of my favorites was 'What are Newton's 3 laws."

2007-09-25 15:33:46 · 13 answers · asked by J Z 4 in Other - Science

3 consecutive even integers are given by x, x+2, and x+4
Find these three numbers such that the sum of the first, two times the second, and three times the third is 124. pliss someone explain how you get to ya answer

2007-09-25 15:32:48 · 8 answers · asked by petite fille 2 in Mathematics

2007-09-25 15:30:14 · 3 answers · asked by momokins 1 in Other - Science

It is required for heavy elements to form. Where is the signature or location of the source of the explosion?

2007-09-25 15:28:18 · 7 answers · asked by photonicboom 1 in Astronomy & Space

answer please.

2007-09-25 15:27:45 · 6 answers · asked by Anonymous in Geography

In designing rotating space stations to provide for artificial-gravity environments, one of the constraints that must be considered is motion sickness. Studies have shown that the negative effects of motion sickness begin to appear when the rotational motion is faster than approximately 1.65 revolutions per minute. On the other hand, the magnitude of the centripetal acceleration at the astronauts' feet should equal the magnitude of the acceleration due to gravity on earth. Thus, to eliminate the difficulties with motion sickness, designers must choose the distance between the astronaut's feet and the axis about which the space station rotates to be greater than a certain minimum value. What is this minimum value?

2007-09-25 15:27:03 · 1 answers · asked by xteen 2 in Physics

Its for a science experiment. My partner and I are going to see which 15 spf tanning lotion tans _______ the most. Thanks in advance.

2007-09-25 15:24:49 · 3 answers · asked by **Silvia** 3 in Other - Science

How can I make a self propelled car?
I am using a rubber band type source for power. I cannot apply any kind of force to the car. I also have to reach 60 meters.

Can anyone help me?
If this helps, I am using a structure similar to a 2 liter V8 bottle.

Sorry, but I'm not alllowed to use any sort of launching device.

2007-09-25 15:24:23 · 1 answers · asked by Luna 4 in Physics

2007-09-25 15:22:59 · 3 answers · asked by rashida1286 1 in Biology

(not taking luck into consideration here bc i have very little of it)
im a senior in high school and im going to be taking my senior picture tommorrow and i really need to know wut is reasonable o expect....because if the weather at this point in time has the potential to completely turn my hair into a monstrosity if it rains.

2007-09-25 15:22:10 · 6 answers · asked by Anonymous in Weather

something to do with the doppler effect and supersonic speeds

2007-09-25 15:21:20 · 2 answers · asked by To-the-Stars 4 in Physics

1) How many grams of Na2Cr2O7 should be added to a 100.0-mL volumetric flask to prepare 0.025 M Na2Cr2O7 when the flask is filled w/ water?

2) You wish to prepare 0.12 M HNO3 from a stock solution of nitric acid that is 15.8 M. How many mL of the stock solution do you require to make up 1.00 L of 0.12 M HNO3?

3) A chemist added an excess of sodium sulfate to a solution of soluble barium compound to precipitate all of the barium ion as barium sulfate, BaSO4. How many grams of barium ion are in a 458-mg sample of the barium compound if a solution of the sample gave 513 mg BaSO4 precipitate? What is the mass % of barium in the compound?

I attempted these questions and my answer was way off from the right ones and I followed an example.

2007-09-25 15:15:24 · 1 answers · asked by keya_na 2 in Chemistry

That's confusing.

2007-09-25 15:13:21 · 3 answers · asked by Christine N 1 in Biology

2007-09-25 15:12:18 · 2 answers · asked by Anonymous in Astronomy & Space

lets say there was a bullet shot completely parallel with the ground, and at that same moment the bullet it shot, an identical bullet is dropped from the same height as the shot bullet. My question is will both bullets reach the ground at the same time? Or will the fact that the bullet was shot affect the speed of its fall?

2007-09-25 15:11:51 · 6 answers · asked by master3rer 1 in Physics

ok so i need help with these answers so i can explain them to my cousin with his homework i need answers and explaining...:)


solve for x
1. 2p=kx-q

2.e=rx

solve for y
1.ry+s=ts-m

2.2/3y+k=j

3.2/3y+a=a+b

2007-09-25 15:11:44 · 7 answers · asked by needs advice 1 in Mathematics