Science & Mathematics - 2 October 2007

A. protons
B. electrons
C. diodes
D. neutrons

2007-10-02 07:36:32 · 5 answers · asked by Felica0429 1 in Engineering

Hi all, I have two problems that i need help with, please explain throroughly if you can

1. find the second derivative of y=e^cos9x
2. An avian disease is decimating the bird population of a South Pacific island. The population at any time (t) is roughly approximated by the equation y=A * e^cos( π /2 * t)
where t is in years, t is between 0-2, and A is the popluation at t=0.

Find the rate at which the population is declining at t=1 (in terms of A)

2007-10-02 07:36:24 · 5 answers · asked by Anonymous in Mathematics

(a) What is the resultant force exerted by the two cables supporting the traffic light in Figure P4.55? (answer in N and in which direction: dwnward,upward, leftward, rightward)


(b) What is the weight of the light? (answer in N)


Here is the image to it...

http://img.photobucket.com/albums/v372/smilytwinkle/trafficlight.jpg

2007-10-02 07:32:11 · 2 answers · asked by pinkepromise 2 in Physics

What volume (in mL) of 0.127 M AgNO3 is required to react completely with 33.92 mL of 0.0750 M FeBr2?

2 AgNO3 + FeBr2 → 2 AgBr + Fe(NO3)2

I got 40.0 mL as the volume. Is this right?

2)How many grams of AgBr are formed?

2007-10-02 07:28:05 · 3 answers · asked by Anonymous in Chemistry

2007-10-02 07:25:29 · 5 answers · asked by Laurie S 1 in Mathematics

x3 – 2x2 + 7x – 14

2007-10-02 07:24:56 · 2 answers · asked by Ivyâ?¥ Left Myspace 1 in Mathematics

A mass on a spring vibrates horizontally on a smooth level surface (see the figure). Its equation of motion, x(t) where t is in seconds and x in centimeters, is given below.
http://img218.imageshack.us/img218/4584/3335wr2.gif
x(t) = 10 sin(t)

(a) Find the velocity, v, and acceleration, a, at time t.

v(t) =

a(t) =

(b) Find the position, x, velocity, v, and acceleration, a, of the mass at time t = pi/ 3.

x ( pi)/3) =

v ( pi)/3) =

a ( pi)/3) =

In what direction is it moving at that time?
The particle is moving to the right, because of (velocity=0, velocity<0, velocity>0, acceleration=0, acceleration<0 or aceleration>0)

2007-10-02 07:22:52 · 2 answers · asked by ineedhelpbadly 2 in Mathematics

2007-10-02 07:22:28 · 2 answers · asked by Anonymous in Physics

2007-10-02 07:21:54 · 11 answers · asked by peachmelba 2 in Chemistry

what is forerun in a distillation process? Why do we discard forerun when distilling?

2007-10-02 07:19:04 · 2 answers · asked by Anonymous in Chemistry

1. find the volume of the solid obtained when the areabonded by the x axis and y= -x^2+4x-3 is rotated about the line y= -1.

plz show me how to do it, cuz i really want to learn it

2007-10-02 07:18:51 · 3 answers · asked by English Wiz 4 in Mathematics

the sequence is 10, 6, 2, -2, -6

I'm an A* target trade (level 8 in recent SATS) maths, but I can't think, this is for my cousin in year 7's homework.

2007-10-02 07:18:24 · 6 answers · asked by GeeMail 4 in Mathematics

Use the equations and relations given below to answer the following questions.
f(pi/6) = 4 f ' (pi/6) = -6
g(x) = f(x) sin(x) h(x) = (cos(x))/(f(x))

(a) g'(pi/6) =

(b) h'(pi/6) =

2007-10-02 07:18:21 · 1 answers · asked by ineedhelpbadly 2 in Mathematics

How much Na2SO4, in grams, must be dissolved in water to produce 77.0 mL of 0.224 M Na2SO4 solution?

2007-10-02 07:16:29 · 1 answers · asked by Anonymous in Chemistry

2007-10-02 07:16:26 · 2 answers · asked by chizoba u 1 in Chemistry

A box of books weighing 300 N is shoved across the floor of an apartment by a force of 410 N exerted downward at an angle of 35.6° below the horizontal. If the coefficient of kinetic friction between box and floor is 0.57, how long does it take to move the box 3.90 m, starting from rest?

2007-10-02 07:14:44 · 2 answers · asked by dazedandconfused 2 in Mathematics

What is the approximate mass of a 1 litre carton of milk?

2007-10-02 07:14:37 · 4 answers · asked by Anonymous in Physics

given that f(pi/2)=2 and f(3pi/2)=-8. find the values of a and b.

2007-10-02 07:14:07 · 2 answers · asked by George 3 in Mathematics

Differentiate the following function.
f (x) = 5 cos x + 4/5 tan x
f ' (x) =

Differentiate the following function.
g (t) = 8 sec t + 9 cot t
g ' (t) =

Differentiate the following function.
y = (sin x)/ (x^6)
y ' =

2007-10-02 07:13:29 · 3 answers · asked by Anonymous in Mathematics

Find the limit for the given function.
lim_(x -> 0) (sin 2 x)/ x

Find the limit for the given function.
lim_(x->0) (sin(5 x))/(sin(6 x))

Find the limit for the given function.
lim_(t->0) (sin)^2(5 t))/t^2

2007-10-02 07:09:23 · 2 answers · asked by Anonymous in Mathematics

What kind of waves do satalites give out? what color?
dont give me the awnseres give me some recorses I want to learn! Im doing a report on Satellites!

2007-10-02 07:08:13 · 2 answers · asked by frog princess 2 in Astronomy & Space

2007-10-02 07:07:17 · 6 answers · asked by Anonymous in Mathematics

real answers plz

2007-10-02 07:07:14 · 3 answers · asked by Anonymous in Weather

2007-10-02 07:03:04 · 2 answers · asked by Anonymous in Mathematics

i mean they say hell is burried beneith the earth! but yet the earth is one big circle and if you keep going down you should head into china!!!! Or maybe is it in between!!!??? not sure this is something i been wanting to know for a long time! just like heaven! they say its up above the sky but yet thats space! if you travel far enough can u reach heaven??? for will space jus continue to go on???

2007-10-02 07:01:21 · 24 answers · asked by Anonymous in Astronomy & Space

2007-10-02 07:01:08 · 7 answers · asked by Anonymous in Astronomy & Space

american size 3 in english sizes (clothes i mean)

2007-10-02 07:00:45 · 1 answers · asked by halo 2 in Mathematics

A friend of mind told me the sun travels from the south east, but I wanted to know does it go towards the east or west, and where does it set?

2007-10-02 06:59:21 · 2 answers · asked by bobbyq85 2 in Astronomy & Space

plz answer the following questions and show working. thanks for your help in advance!

a) what is the gram formula mass of Mg(NO3)2 (show working)
b) how many moles in 16g CuO
c) what concentration of solutions is obtained if 4.0g of NaOH is dissolved in water and made up 250cm^3 of solution

2007-10-02 06:58:23 · 4 answers · asked by S 1 in Chemistry

Please don't give me annoying unwanted answers.

Here's the question, just point me in the right direction:

"Our interplanetary scientist, Cefor, has sent some electronic cards from her visits to places in our solar system. You have asked her to tell you her weight and mass at each place.

Moon:
Mass - 10 kg
Weight - 11.6N

Venus:
Mass - 10kg
Weight - 90N

Mercury
Mass - 10kg
Weight - 40N

When Cefor left Earth, she had a mass of 10kg and a weight of 100N.

Task: Draw a force diagram for Cefor standing still on Earth and on the three other places. Use the level ladder instructions to help explain your ideas.

Key words: acceleration, force, gravity, killograms, mass, Newtons, reaction"

I'll be really grateful if you help me!

Thanks x x

2007-10-02 06:55:58 · 1 answers · asked by myspace.com/rock_4_the_world 1 in Astronomy & Space