Science & Mathematics - 5 September 2007

2007-09-05 18:11:13 · 4 answers · asked by winchy 1 in Weather

2007-09-05 18:10:42 · 5 answers · asked by salt 1 in Physics

The earth and moon rotate around a common center of mass called the barycenter as they revolve around the sun. However, since the mass of the earth is about 80 times the mass of the moon, the barycenter is much closer to the center of the earth than the center of the moon. In fact, the barycenter is located within the earth, about 1707 km below its surface.

2007-09-05 17:58:04 · 3 answers · asked by Anonymous in Astronomy & Space

This is an interview question and I could not solve it after breaking my head over it.

Write any 3 numbers. It is always possible to find a subset (of size 1,2 or 3) of ADJACENT numbers among these 3 numbers that add up to a multiple of 3. Why is this so?
Generalizing, write any 'n' numbers. It is always possible to find a subset of adjacent numbers from among them that add up to a multiple of "n". Why is this so? Give proof.

2007-09-05 17:53:09 · 11 answers · asked by senthil k 1 in Mathematics

What is THe scientific methods and tell me the steps to scientific methods please

2007-09-05 17:52:43 · 3 answers · asked by Paul Aka-Twinkie 1 in Biology

I am trying to complete my algebra homework, but am stuck on three problems. Could someone help me solve these? And could you please show your work and simplify the problems? I won't learn anything if I just see the answer. Thank you SO VERY MUCH in advance for your help!!!

-4.0x+2.7-1.6=-4.6x+2.7
x=?

-5(3w-3)+(1+16w)=0
w=?

-5(1-2z)+4(3-z)-7(3+z)=0
z=?

Thanks again!!!

2007-09-05 17:52:12 · 6 answers · asked by mrsdynamite 2 in Mathematics

2007-09-05 17:47:27 · 1 answers · asked by Anonymous in Chemistry

1.A ball is thrown downward, with an initial speed of 6.34 m/s, from a height of 45.2 m. After what time interval does the ball strike the ground?


2. A dog searching for a bone walks 4.31 m south, then runs 8.93 m at an angle 22.0 north of east, and finally walks 10.0 m west. Find the magnitude of the dog's resultant displacement vector.

3.A dog searching for a bone walks 2.87 m south, then runs 22.5 m at an angle 30.5 north of east, and finally walks 5.91 m west. Find the direction of the dog's resultant displacement vector. Give your answer as an angle in degrees, with the angle measured counterclockwise from the line pointing straight East (North is 90, while South is -90).

2007-09-05 17:44:59 · 3 answers · asked by Anonymous in Physics

Please give a detailed example on how to solve it. Math and reasons on how you solved it, thanks.

2007-09-05 17:33:47 · 3 answers · asked by Anonymous in Chemistry

Hydraulic engineers often use, as a unit of volume of water, the "acre-foot", defined as the volume of water that will cover 1 acre of land to a depth of 1 ft. A severe thunderstorm dumps 2.9 in. of rain in 30 min on a town of area 24 km2. What volume of water, in acre-feet, fell on the town?|

2007-09-05 17:30:03 · 1 answers · asked by sugardaddy8815 1 in Physics

A bus leaves a station at 1 P.M., traveling west at an average
rate of 44 mi/h. One hour later a second bus leaves the same station, traveling
east at a rate of 48 mi/h. At what time will the two buses be 274 mi apart?

2007-09-05 17:24:49 · 5 answers · asked by thecookfamily00 1 in Mathematics

ANSWER QUICKLY please =]

2007-09-05 17:24:30 · 10 answers · asked by lambofgod925 2 in Chemistry

the difference between the horse and the ass.
why does the goose never cross the chalky line drawn round about it?

2007-09-05 17:24:12 · 1 answers · asked by petlams 1 in Engineering

this question is so easy yet hard, i know how to do it but it doest look right.

you are taking part in a charity walk a thon where u can either walk or run. you walk at four kilometers per hour and run at 8 kilometers per hour. the walkathon last 3 hours. money is raised based on the total distance you t ravel in the three hours. ur sponsors donate 15 dollars for every kilometer u travel. write an expression that gives the total amount of money u raise. evaluate the expression if u walk for two hours and run for one





OHH MYH AND!!

2007-09-05 17:20:24 · 10 answers · asked by مدينا Medina ☪ 6 in Mathematics

2007-09-05 17:17:17 · 2 answers · asked by Anonymous in Chemistry

Lately, I've noticed that the blood vessels in my arms, hands, legs, and feet are wider than usual...dilated, in other words. I recently stopped taking my prescriptions for depression and ADHD a week ago and I haven't noticed a return to my previous depressed, anxious, ADHD self; it's almost like I've been miraculously cured. I stopped the medications because after years of taking them, they were greatly increasing my pulse and blood pressure and causing arrhythmias. I've suffered from mental illness for half of my life and now I find myself suddenly going into remission for no apparent reason. It's funny because for the past couple of years, I would be suicidal if I wasn't on medication and now I'm not on anything and I feel normal! Anyways, I was wondering if my enlarged blood vessels and lowered pulse (dropped from 90+ bpm to 65-70 bpm) is a result of the drugs leaving my system. Is there any correlation? Thank you!

2007-09-05 17:17:15 · 3 answers · asked by Ben 3 in Medicine

2007-09-05 17:15:47 · 4 answers · asked by Anonymous in Other - Science

any recommended reading

2007-09-05 17:15:43 · 6 answers · asked by dan 1 in Biology

find the exact value of each of the remaining trig functions of theta.

sin theta = -2/3, 180 degrees < theta < 270 degrees

how do I do this?? Please help and explain, thanks

2007-09-05 17:15:20 · 3 answers · asked by rickyricardoiscool 1 in Mathematics

including screening and macerating solids,,(teeth), seperating solids from liquids, (side streams in the body leading to liver, kidneys, bladder, etc..), and temperature (98.6 in both digesters and humans ), and PH balance similar in digesters and humans...finally waste effluent in the plant is chlorinated and transferred to receiving waters...In humans urine is sterile and is transferred back to the sewer...There are many more similarities, too many to recount here,,,such as bacterial oxidation of solids. Also when digesters in the plant get "upset" they are dosed with lime or alkalines to raise PH levels....any way, my question actually is, is this all coincidental, or did the first waste water engineers model the plant process directly from the human body???....anybody know??? thx. in advice for answer..

2007-09-05 17:13:20 · 2 answers · asked by Anonymous in Chemistry

I've been trying to find a number but every site seems to have something different and I'm not sure which one is most reliable and most accurate.

Any help is greatly appreciated :)

2007-09-05 17:12:36 · 3 answers · asked by music123 1 in Biology

Hi guys. I'm just having difficulty with this one problem. There were two, I answered the first one which was:

1. Calculate how much 95% ethyl alcohol will be required to dissolve 0.3g of sulfanilamide at 78 ' C.

I got 300 mg sulfanilamide ( 1ml / 210mg SAmide) = 1.42867143ml.

Now it is asking:

2. Using the volume of solvent calculated in Step 1, calculate how much sulfanilamide will remain dissolved in the mother liquor after the mixture is cooled to 0 ' C.

I know the solubility of sulfanilamide at 0 ' C is 14 mg/ml but I don't know where to go after this. Please help me understand this problem! Any help will be much appreciated. We are doing a Semimicroscale Crystallization lab using Erlenmeyer Flasks and a Hirsch Funnel. Thank you all in advance!

2007-09-05 17:10:27 · 4 answers · asked by Anonymous in Chemistry

using the reference angle to find the exact value of each expression . . . without calculator

a) csc (7pi)/4, I said it's coterminal with (pi/4) so csc (7pi)/4 = csc (-2pi +(pi/4)) so csc = (pi/4) = sq root 2

did I do this right??

and how would i do this one??

b) cos (2pi) / 3


and c) sec (11pi)/4

sorry my book does a crappy job explaining this so I'm just having a hard time, if you could please help me, I would appreciate it! THANKS

2007-09-05 17:08:42 · 3 answers · asked by rickyricardoiscool 1 in Mathematics

i have a box of pills that contain piperazine dihydrochloride...what is that and what does it do?

2007-09-05 17:08:02 · 6 answers · asked by Miss Candylicious 1 in Medicine

I completely lost. Some people have suggested L'Hospital's Rule and some other stuff that my class hasn't covered. Right now, the teacher simply wants us to solve algebraically, not using some special properties. For example, in
lim x-->0 of sin2x / x I multiplied the top and the bottom by 2, making 2sin2x/2x, can celling the sin2x/2x, and leaving 2, so the limit was = 2. Something similar has to be done with these problems, thing is, I have no clue what to do.

remember that
sinx/x = 1 and 1-cosx/x = 0

I also don't know how to algebraically solve these 2 (and by the way, this is not homework, just practice for an upcoming test)

#3:
what is [ lim x-->0 ] the limit of ( sin^2(x) ) / (x) ?

#4

what is [ lim x-->0 ] the limit of ( x^2 ) / ( 1-cos(x) ) ?

and of course, the one in the actual question,

what is [ lim x-->0 ] the limit of ( x + sin(x) ) / (x) ?

2007-09-05 17:06:02 · 5 answers · asked by gatortheone 1 in Mathematics

I thinki that underground colonies would be 10 times safer than domed colonies, on the surface there is massive sand storms, high levels of solar radiation, and greater chances of meteors that could shatter the dome and breach the internal atmosphere, and with a underground colony the massive amount of soil would offer natural protection from high radiation, sand storms, and even protection from meteors, so i would say i would feel safer living in a underground colony than on the surface, what about you, would you live on the surface of Mars or underground on Mars?

2007-09-05 17:05:45 · 6 answers · asked by Anonymous in Astronomy & Space

Why does the same person keep answering all my questioins??

2007-09-05 17:03:13 · 7 answers · asked by Royal 4 in Zoology

How do you make the infinity symbol on the computer?

2007-09-05 17:01:27 · 6 answers · asked by Anonymous in Mathematics

four identical metallic object carry the following charges +1.6, +6.2, -4.8, -9.4 C. the object are brought simultaneously into contact so that each touches the other then they are separated what is the final charge each object? how many electrons make u p the final charge on each object?

2007-09-05 17:00:53 · 1 answers · asked by Foxx 1 in Physics

Is there a formula I can use to get the answer? Thank you!

2007-09-05 16:59:30 · 5 answers · asked by c_eva02 2 in Mathematics