Science & Mathematics - 5 November 2007

2007-11-05 07:33:10 · 5 answers · asked by Anonymous in Mathematics

Say you have a rubber ball with air interior.
Both the rubber ball and the air exhibit spring-like behaviour.
Using Hooke's equation for the rubber (i.e. k = F/x) and the Air Spring Equation for the air ( k = γ.P.s / L), could you compare the stiffness (k) between one another and say which one contributes more to the spring effect that the ball exhibits per unit volume?

2007-11-05 07:27:39 · 5 answers · asked by saman-a-man 1 in Physics

A 1270 N uniform beam is attached to a vertical wall at one end and is supported by a cable at the other end. A W = 1860 N crate hangs from the far end of the beam

(a) Calculate the magnitude of the tension in the wire. Newtons

(b) Calculate the magnitude of the horizontal and vertical components of the force that the wall exerts on the left end of the beam

Fx = N
Fy = N

http://img107.imageshack.us/img107/9378/p966altcu2.gif

2007-11-05 07:26:19 · 1 answers · asked by Anonymous in Physics

I know this sounds crazy but I've used a calculator for the past 10 years and now that I'm in uni they won't let me and I don't remember how to do multiply or divide! I can do the very basic stuff but how would you multiply something like 2 x .02? Or divide 200 by 45?

Thanks for the help!

2007-11-05 07:25:27 · 13 answers · asked by Simon F 2 in Mathematics

2007-11-05 07:24:28 · 7 answers · asked by BODIN 1 in Astronomy & Space

There is a solar system that make the water hot in summar. I am thinking about a way to save the heat energy to use it in the winter.

2007-11-05 07:23:04 · 5 answers · asked by Amiraan 4 in Engineering

jims second test score was 8 points higher than his first test score. his third score was 88. he a b average (between 80-89 inclusive)for the three tests.

2007-11-05 07:22:45 · 1 answers · asked by clcsexyma1 1 in Mathematics

Why don't we float off the earth?

2007-11-05 07:21:56 · 8 answers · asked by Jansen J 4 in Astronomy & Space

In the early morning hours of June 14, 2002, the Earth had a remarkably close encounter with an asteroid the size of a small city. The previously unknown asteroid, now designated 2002 MN, remained undetected until three days after it had passed the Earth. Suppose that at its closest approach, the asteroid was 78300 miles from the center of the Earth -- about a third of the distance to the Moon.

(a) Find the speed of the asteroid at closest approach, assuming its speed at infinite distance to be zero and considering only its interaction with the Earth.

(b) Observations indicate the asteroid to have a diameter of about 2.0 km. Estimate the kinetic energy of the asteroid at closest approach, assuming it has an average density of 3.33 g/cm3. (For comparison, a 1-megaton nuclear weapon releases about 5.6

2007-11-05 07:21:50 · 2 answers · asked by Anonymous in Physics

2007-11-05 07:19:09 · 6 answers · asked by btammy99 1 in Mathematics

the lengths of an isosceles triangle are integers. the base is half as long as each leg.

2007-11-05 07:19:04 · 1 answers · asked by clcsexyma1 1 in Mathematics

Sorry to keep bothering, I just seem to have a problem on each exercise *hides*

I got the more simple reactions, but when I'm thrown HCL and FCl2 I'm lost...
-------------------------------

Fe(s) + HCl(aq) ---> FeCl2 (aq) + H2 (g)

Balanced: Fe(s) + 2HCl(aq) ---> FeCl2 (aq) + H2 (g)

Oxidation numbers for each:
Fe = 0
2HCl === H=2(+1)=+2, Cl=2(-1)=-2
FeCl2 === Cl2 = 2(-1)=-2 therefore Fe= +2?
H2 = 2(1) === 2

If I'm right... only Fe is oxidized. Which is reduced? H stays 2 and Cl too.

Fe ---> Fe2+ - 2e-

2007-11-05 07:17:56 · 2 answers · asked by Pancha Pistolas 3 in Chemistry

I have a non calculator maths gcse exam tomorow, and a question similar to this is bound to come up: I have added a link please could you solve and explain how its done, thank you soo much.
http://img.photobucket.com/albums/v201/starmate/mathsQ13.jpg

2007-11-05 07:17:20 · 3 answers · asked by Starmate 1 in Mathematics

2007-11-05 07:17:13 · 2 answers · asked by Jen P 1 in Chemistry

2007-11-05 07:13:32 · 27 answers · asked by gizzle 1 in Engineering

16" unlined ductile iron pipe, ID = 17.1", OD = 17.4"
Starting water temp = 50 °F
Ambient air temp = 7 °F
Therm cond of ductile iron pipe, k = 36 W/m K
Heat loss, Q = -kA(T2-T1)
A = surface area of pipe per meter of pipe = PI*(.5*OD)^2 = 0.15 sq m / m of pipe
Q = -36*0.15*(283-260) = -132 Watts/meter of pipe

Now calculate the time it takes to cool the mass of water in 1 m of pipe from starting temp
Of 50 °F to 32 °F

Time to cool = Q / heat capacity of water / mass of water per m of pipe / (273 K – 283 K)
Where
Heat cap of water = 4200 J/kg per degree K
Mass of water in 1 m of pipe = 148 kg per m of pipe
Freezing point of water = 32°F = 273 K
= 13 hours

Now, determine the time to freeze water at 32°F

Time = Q / latent heat of fusion for water / mass of water in pipe per meter
Where
Latent heat of fusion of water = 334,000 J/kg
= 104 hours
Total time to cool water from 50°F to freeze it is 13 hr +104 hr = 117 hr, this seems too high

2007-11-05 07:11:12 · 1 answers · asked by Jim K 1 in Engineering

I am hearing all about planets alignment and such according to the "Mayan Calendar". I read quite a bit into this on a daily basis and it isn't the planets alignment that the mayans predict in 2012...which would explain the mix up of it actually happening in 2010, that is going to be the earths doom (NOT)...it's the alignment of the galaxy that lies between two star coordinates and the sun in our solar system that is supposed to off balance all the planets gravitational pulls and magnetic inner earth bars, turning our North into South and so fourth. However, according to mayan past theorizing, the date 11, 11, 11, 11, 11 etc. is not and could not ever really be December 21st 2012 for two very good reasons. 1) Mayans ended every month on the 20th and never the 21st. 2) that date 11 11 11 11 11 etc., was prerecorded already in their calandar..it is August 15th 1600 or so more before christ.(BC) so there is no way it could be 2012. It is merely an end to a 5000 year old calendar.

2007-11-05 07:11:09 · 8 answers · asked by Dawn 1 in Astronomy & Space

If the graph of f contains the points ( -1, 3), ( 0, 4) and ( 2, -7) list the points that would be found on the graphs of each of the following functions:
a) f (x – 3)
b) f (x) + 3

2007-11-05 07:09:03 · 3 answers · asked by Anonymous in Mathematics

I'm in a class with two seperate parts. Lets call them part a and part b.

Part A=80% of grade
I got 290/330 points

Part B=20% of grade
I got 90/105 points

What will I get overall?

2007-11-05 07:08:44 · 5 answers · asked by Anonymous in Mathematics

[n(n - 3)!] / n!

2007-11-05 07:08:31 · 2 answers · asked by Katie 1 in Mathematics

I have a resistor that is reading 500 ohms (instead of 1K ohm) after an over-current, the color code is burn so I cannot identify if the original value was 1k or not.
Is there any possibility that a resistor reduce its value?

Thanks

2007-11-05 07:07:55 · 3 answers · asked by rafael 1 in Engineering

Can this be applied to underground travel. I have to design a probe to send to the mantle and send data to the surface for my science project.......HELP QUICK due tomorrow!!!!!!!

2007-11-05 07:07:48 · 5 answers · asked by Anonymous in Astronomy & Space

Find the exact functional value using the cosine sum or difference identity.

sec (-pi/12)

2007-11-05 07:07:42 · 2 answers · asked by I C 1 in Mathematics

is there a way to make a device that can kill electricity such as a gun that sends frequency to kill an electricity for cars while car is running?
If so, how can I do it?
how much will it cost?

2007-11-05 07:05:22 · 5 answers · asked by sungil 1 in Engineering

i am doing a science fair project on that question and i kinda need an idea of what im doing

2007-11-05 07:02:38 · 3 answers · asked by Anonymous in Chemistry

Say a test had 175 questions and you missed 20. How would you figure the percent you got right or wrong? It's been over 20 years since I was in school & I forgot how. Don't you divide 175 by 20?

2007-11-05 07:02:08 · 32 answers · asked by ♥bigmamma♥ 6 in Mathematics

Through (7, -5) and (0, -3)

2007-11-05 06:58:13 · 3 answers · asked by . 1 in Mathematics

I am asking this in order to apply it to communication underground with those on the surface: NB i do not beleive in underground civilizations...its a science project...thats all.

2007-11-05 06:58:06 · 6 answers · asked by Anonymous in Astronomy & Space

You give the importants of Agricultuaral products to the community.

2007-11-05 06:53:41 · 5 answers · asked by Asubasi Y 1 in Agriculture

I'm getting associates degree in business nad currently doing algebra do we need algebra in business degree?

Also what is the highest paying career or job in business?

2007-11-05 06:51:22 · 2 answers · asked by BeBop 3 in Mathematics