Science & Mathematics - 7 October 2007

a flute open at both ends and an organ pipe closed at one end have the same length
organ pipe has a fundamental frequency of 130hz
what is the flutes fundamental frequency and what assumptions are we making

2007-10-07 09:57:56 · 1 answers · asked by Anonymous in Physics

this is a side question to:
http://answers.yahoo.com/question/index;_ylt=AoOIrcTNh2O5KMiYAddkQ87sy6IX;_ylv=3?qid=20071007123550AA8VHBk

(anyone who answers that one PROPERLY gets 10 points from this too, seeing as they're related)

but how many valence electrons does chromium have?

2007-10-07 09:56:00 · 2 answers · asked by Z3DA 3 in Chemistry

if f(x) = -2x^2 + 6x + k and f(0)= -1, find k?

I want to know HOW it's done and WHY you do what you do in the problem. In other words, explain what you did.

Best answer gets 10 points.

2007-10-07 09:55:18 · 2 answers · asked by dosahyd f 2 in Mathematics

2007-10-07 09:53:59 · 12 answers · asked by 00000 3 in Astronomy & Space

Do you think that there's a color on the color spectrum, or somewhere else, that we have not discovered? Maybe even one visible to humans that we just don't know of and can't even describe nor imagine what such a color looks like?

Is it possible?
On the visible color spectrum, there does seem to me to be very small changes that seem more rapid than in other places. Maybe we're even missing a few colors from the spectrum.

2007-10-07 09:52:45 · 15 answers · asked by Casey 4 in Other - Alternative

solve on the interval 0 < equal to theta < 2pi


D) cos(2theta) = 2 - 2 sin^2 theta

E) cos (2theta) + 5 cos theta + 3 = 0


please help and explain, thanks!!

2007-10-07 09:52:00 · 3 answers · asked by Anonymous in Mathematics

My science idea's final draft is due tis Wednesday...I am planning to use 4 tablets and HCl...but I don't know wat to test it for...I dont want to do product testing to see which one dissolves etc....I need something tats new and interesting...someone plzz help me...im desperate!!!!

2007-10-07 09:46:02 · 1 answers · asked by lilaznchica 1 in Other - Science

A curve of radius 155 m is banked at an angle of 24°. At what speed can it be negotiated under icy conditions where friction is negligible?

I think I can get it but i dont know how i am going to use just angle and radius to solve this. I need to somehow get the force to get velocity but i dont have mass. Help?

2007-10-07 09:39:45 · 1 answers · asked by Anonymous in Physics

dy/dx of sin(sin x) is cos(sin x)*cos x, but what then? and i'm really not sure about the ln question...

2007-10-07 09:37:25 · 2 answers · asked by Maths student 1 in Mathematics

i need help learning how to acomplish this any pointers

2007-10-07 09:34:13 · 10 answers · asked by Anonymous in Paranormal Phenomena

You find yourself on a strange planet, and have rigged a setup with a launcher that is 5 meters off the ground, and the launcher will shoot a projectile with an initial velocity of exactly 4.0 m/s. The projectile travels 4.5 m along the ground. From this, you conclude that free-fall gravitational acceleration on this planet is _______ m/s^2.

The answer is supposed to be 7.9 m/s^2.

When I was finding all of the x and y values, this is what I came up with:

X-direction: displacement = 4.5 m
acceleration: 0 m/s^2
initial & final veloctiy: 2.97 m/s
time: 1.51 seconds

Y-direction: displacement: -5 meters
Initial velocity: -2.67 m/s
time: 1.51 seconds.

I guess its possible that I keep messing up the algebra when trying to find the free fall acceleration, but I think its more likely that I came up with one or more incorrect values for the known information (particularly the inital velocities). I'd greatly appreciate it if someone could enlighten to as to where I'm going wrong.Thanks.

2007-10-07 09:33:08 · 1 answers · asked by Anonymous in Physics

2007-10-07 09:28:59 · 7 answers · asked by Blaine S 1 in Biology

2007-10-07 09:27:58 · 4 answers · asked by Anonymous in Zoology

2007-10-07 09:26:44 · 7 answers · asked by Anonymous in Mathematics

I forums I always see "evolutionists" (I pray to Darwin too) claim humans don't come from monkeys, but share a common ancestor. Can someone explain this? Because according to my knowledge we come from chimps, or at least their ancestors. As the other apes (gorillas, orang utans) are also monkeys, and split off before the chimps and humans did, it's not hard to conclude that our common ancestors were monkeys. They didn't all spit off and all accidentally became monkeys. Also according to this time line of human evolution we do come from chimps:
http://www.livescience.com/php/multimedia/imagedisplay/img_display.php?pic=060508_human_evolution_02.jpg&cap=The+timeline+of+human+evolution+is+long+and+controversial,+with+significant+gaps.+Experts+do+not+agree+on+many+of+the+start+and+end+points+of+va

So do I have a bad understanding of human evolution (please explain), or does everybody else just say the common ancestor thing not to disturb the anti-evolutionists too much?

2007-10-07 09:26:36 · 7 answers · asked by Batfish 4 in Biology

Is there a difference or are they the same thing?

2007-10-07 09:23:18 · 3 answers · asked by rnbwgrl 2 in Zoology

2007-10-07 09:14:32 · 3 answers · asked by Stephen 1 in Mathematics

A bicycle tire rolls without slipping along the ground with its center of mass moving with speed v . You may neglect any rolling resistance. What is the speed with respect to the ground of each of the following 4 points on the wheel?
a) at the top of the wheel
b) at the 3 o'clock position of the wheel
c) at the 9 o'clock position of the wheel

so i've been trying to figure this problem out for a while and i'm not sure how to go about it. there's a tangential velocity (v) at every one of these points but how do you take angular acceleration into account in this case? how do you figure out which direction the speed at each of the points takes?

2007-10-07 09:03:40 · 3 answers · asked by Anonymous in Physics

Helllo can someone please tell me what this bug/insect isi found it in my house ..

link to picture.

http://www.flickr.com/photos/14709305@N06/1507840483/

Thanks

2007-10-07 09:00:43 · 12 answers · asked by tigpig2 1 in Botany

2007-10-07 09:00:27 · 3 answers · asked by futrmd17 1 in Mathematics

What would the affect be of our atoms being bigger that the same atoms of a smaller universe?

2007-10-07 08:59:12 · 2 answers · asked by Mr. Bodhisattva 6 in Physics

The question reads:

A roof truss is made of two rafters, and a tie beam. Each end of the tie beam is supported by a wooden post. If a 100kg mass is suspended from the rafters, as shown, determine:

a.) The compression in each post
b.) The compression in each rafter
c.) The tension in each tie beam

So the diagram is an isoceles triangle sitting on two posts. The length of the base of the triangle is 12.0m, and the 100kg mass is hung from the top of the triangle.

I got the force of gravity on the mass (981N [Down]), and the length of each rafter (6.5m) and their angle to the 12.0m base (25* each).

But I don't know what to do from there.

2007-10-07 08:55:43 · 1 answers · asked by Anonymous in Physics

A car moving westward along a straight, level road increases its velocity uniformly from 24 m/s to 25 m/s in 10 s.
(a) What is the car's acceleration?
m/s2 (westward)
(b) What is its average velocity?
m/s (westward)
(c) How far did it move while accelerating?
m


I tried to solve this out but, for some strange reason im not able to come up with the correct answer. Can anyone show me how to solve this problem. Please.

2007-10-07 08:49:19 · 2 answers · asked by Anonymous in Mathematics

Why do I always see them flying in formation to the west, east or north (in the Fall)?
My theory is that maybe they are going to a rendezvous point or feeding ground to meet other groups before heading south.

2007-10-07 08:49:01 · 5 answers · asked by FUNdie 7 in Zoology

2007-10-07 08:42:19 · 2 answers · asked by Nathan G 1 in Medicine

2007-10-07 08:36:20 · 3 answers · asked by longtallgeorge 1 in Zoology

2007-10-07 08:34:23 · 6 answers · asked by CelticMoonGoddess 2 in Mathematics

the qusetions are as follows:
A car moving westward along a straight, level road increases its velocity uniformly from 24 m/s to 25 m/s in 10 s.
(a) What is the car's acceleration?
m/s2 (westward)
(b) What is its average velocity?
m/s (westward)
(c) How far did it move while accelerating?
m


I thought to figure this problem out I would have to take the final velocity (25m/s) minus the original velocity (24 m/s) diveded by the time (10 s). which would give me .1 m/s/s (.1 m/s^2) . But, this stupid webassign homework is kicking my ***.

2007-10-07 08:32:36 · 2 answers · asked by Anonymous in Physics

in a boiler hot water from the boiler rise and flows into the tank where it rises to teh top. when you use a hot water tap at home, you draw off hot water from teh top of the tank. what would happen if we connected the hot taps to the bottom of the tank? plz reply in convectional terms! thankyu :)

2007-10-07 08:29:20 · 1 answers · asked by Anonymous in Physics

DNAase are destroyed in hot conditions like most enzymes, what might happen if you leave DNAase in hot conditions for more than 15 minutes?

2007-10-07 08:28:48 · 1 answers · asked by Jama D 1 in Biology