Science & Mathematics - 21 October 2007

is there a web site or something that can help me

2007-10-21 12:26:46 · 1 answers · asked by Anonymous in Chemistry

The Reflector on a bicycle wheel is 15cm from the rim. The diameter of the wheel is 76cm at time = 1/2 sec, the reflector is at its lowest point; 3/4 sec later it returns to the same position.Find an equation which will locate the height of the reflector above the ground at any time t.

a) Find height when t=5.2 sec
b) Find the 1st time the reflector is at a height of 59cm above the ground

Can u help me find the equation i have one but i dont know if its correct

Equation- y = -23 Cos [ 2pi/.75(x-.5)]+38
can u comfirm this? plz so i can calculate a & b

2007-10-21 12:25:45 · 1 answers · asked by Kruschiv 1 in Mathematics

The function f(x) = 72,900/100x^2+729 models the percentage of people in the United States who are unemployed as a function of years of education, x.

Find and interpret f(0)
Find and interpret f(20)
Is there an educational level that leads to guaranteed employment? If not, how is this indicated by the equation of the horizontal asymptote associated with this function?

PLEASE ONLY ANSWER IF YOU ARE CONFIDENT IN YOUR RESPONSE THANX!!

2007-10-21 12:25:07 · 1 answers · asked by diamondintheruff 2 in Mathematics

i want to know you eon the rase today from martinsvill virginia

2007-10-21 12:23:24 · 2 answers · asked by ann w 1 in Earth Sciences & Geology

I have three questions about Mars so please answer them!

1. What evidence supports the theory that life existed on Mars in the past?

2. Are conditions on Mars currently favorable for life-forms?

3. Does most of today's scientific community belive that life presently exits on Mars?

If you have any other valuable info on Mars please tell me. (I need it for a report) Thank you so much =)

2007-10-21 12:22:17 · 7 answers · asked by Anonymous in Astronomy & Space

Please help me solve for y

2007-10-21 12:21:41 · 1 answers · asked by Paul G 1 in Mathematics

2007-10-21 12:18:04 · 3 answers · asked by amani h 1 in Mathematics

2007-10-21 12:17:04 · 11 answers · asked by BOX 4 in Agriculture

2007-10-21 12:16:57 · 7 answers · asked by amani h 1 in Mathematics

Show that fxx + fyy + fzz = 0 when w= f(r,theta,z) = ln(r) +3z

I thought I could just take the second derivs based on r,theta,z, but that doesnt work out. So im guessing I need to convert into x,y,z, but I can't figure out how to do that.

Help is appreciated. Always give best answer.

2007-10-21 12:15:33 · 1 answers · asked by James B 3 in Mathematics

If density= mass/volume
than what would the formula be to find mass?
-------------------------------------------------------------
would volume= mass/ density
or volume= mass X density?

2007-10-21 12:15:20 · 6 answers · asked by Anonymous in Physics

title says it. i have a pedestal fan, that for the last few days has been making squeaky noises. now when i turn it on, it makes half a spin and then stops short. i can still hear the engine making an effort. when its not on i can make it spin smoothly. but when its on i cant make it spin easily since it stops at certain zones. i've cleaned it internally. and oiled it at the bearings.

2007-10-21 12:10:54 · 1 answers · asked by oldarney 3 in Physics

Apologies if this is a really simple question (I think it is :P)

1 / ( 4 - sqrt(8) )

Give this in the form a + b*sqrt(2).

2007-10-21 12:09:23 · 1 answers · asked by Mark 2 in Mathematics

1/2 + 2/3 x 1/3

1/9 + 3/8 (divided by) 9/4

9/14 - 1/2 x 1/2

13/16 - 25/18 (divided by) 10/3

2007-10-21 12:08:22 · 6 answers · asked by Anonymous in Mathematics

Can someone give me an explanation on how to solve it plus the answer? There are many more q's like it so I am not really cheating...

the height of a cube is 2x cm, the width is x cm and the length is (x + 1) cm
Find the value of x, to two decimal places for which the cuboid has a volume of 8 cm 3 (cubed)

2007-10-21 12:07:03 · 3 answers · asked by browncow 1 in Mathematics

In what part of the body, besides the heart, could you be stabbed and die within ten minutes?

2007-10-21 12:03:47 · 11 answers · asked by [192882] 5 in Biology

2007-10-21 12:01:01 · 4 answers · asked by Anonymous in Zoology

The simplest arithmatic method is quadratic formula; correct?

I'm not looking for the answer; I just want to be clear that there is not an easier arithmatic method. Thanks

2007-10-21 11:59:10 · 3 answers · asked by RogerDodger 1 in Mathematics

2007-10-21 11:55:39 · 1 answers · asked by Anonymous in Botany

Basically all i want to know is where the continents will be, and how life would change in 1 million years, from the continents moving.

2007-10-21 11:54:10 · 2 answers · asked by Anonymous in Earth Sciences & Geology

2007-10-21 11:52:27 · 5 answers · asked by Anonymous in Weather

PLEASE HELP!

2007-10-21 11:51:18 · 7 answers · asked by Anonymous in Mathematics

floating around after physical death is there a scientific, physics based reason for this??? no religious answers please, I want actual theories based on reality.

2007-10-21 11:45:03 · 11 answers · asked by Anonymous in Paranormal Phenomena

2007-10-21 11:38:32 · 11 answers · asked by SASSY 1 in Mathematics

Is there any way to solve the 1/x ∫ x^2 sin (4.156/x) dx without using a calculator? I think you can pull out the x^2 from the integral to make it x ∫ sin(4.156/x) but I don't know how to go from there. Help is greatly appreciated.

2007-10-21 11:35:48 · 2 answers · asked by Satrivaini 1 in Mathematics

2007-10-21 11:35:31 · 1 answers · asked by Anonymous in Mathematics

find the second order derivative and evaluate at x=3

y = 10x^3 + 8x^2 + 19

f(x) = (4x - 1)(3x^2 + 2)

find the successive derivatives and evaluate at x=2

f(x) = 2x^3 + 7x^2 + 9x - 2

f(x) = (8 - 2x)^4

please help me with that lol:) ..id really, really appreciate it :)

2007-10-21 11:35:13 · 1 answers · asked by Mathema-what?! 1 in Mathematics

2007-10-21 11:33:03 · 2 answers · asked by geography39 1 in Earth Sciences & Geology

What was the purpose of the manganse (IV) oxide added to the hydrogen peroxide in the generation of oxygen? Could any other substance have been used for this purpose?

2007-10-21 11:32:51 · 1 answers · asked by Whats the Scoop? 2 in Chemistry

well?

2007-10-21 11:30:58 · 39 answers · asked by Anonymous in Weather