Science & Mathematics - 28 January 2007

I plan to conduct a demonstration lesson on stoichiometry using copper (II) sulfate which i plan to hydrate. Is it as simple as computing for the mass of the anhydrous and adding the mass of 5 moles of water?

2007-01-28 05:29:23 · 2 answers · asked by Marinela C 1 in Chemistry

2007-01-28 05:29:11 · 5 answers · asked by babu 1 in Zoology

How is Russian gold used in plating jewlery?

2007-01-28 05:28:11 · 3 answers · asked by Vintage-Inspired 6 in Chemistry

Fill in the blank with always, sometimes, or nerver:
1. An equation of the form x squared=k ___, has real number solutions.
2. A quadraic equation can ___ be solved by completing the square.
3. if the value of b sqaured - 4ac is negative, the equation ax squared + bx+c =0 ____ has real number solutions.
4. The quadraic formula a can ___ be used to solve quadraic equations.

True of False for the following questions:
5. Completing the square is used to develop the quadraic formula.
6. The quadraic formula will not work on the equation x squared - 3=0
7. If a =2, b=-3, and c=-4, then b squared - 4ac =41.
8. if the discriminant is zero, then there are no imaginary solutions.
9. to solve 2x-x squared=0 by the quadraic formula, let a=-1,b=2, and c=0.
10. Two numbers have the sum of 6 can be represented by x and x+6.
11. Some quadraic equations have one real and one imaginary solution.
12. In a complex number system, any quadraic equation has either one or two solutions.

2007-01-28 05:27:27 · 4 answers · asked by hans d 1 in Mathematics

The following question was posed many years ago in a newspaper column by Marilyn Vos Savant,
"Suppose you're on a game show, and you are given a choice of three doors. Behind one door is a car; behind the others, goats. You pick a door--say, No. 1--and the host, who knows what's behind the doors, opens another door--say, No. 3-- which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?"

I know that yes, you should switch because the probability is 2/3 that it is in the other door. (If you don't agree, check out http://www.marilynvossavant.com/articles/gameshow.html for the full explination.)

How do I answer the questions at the end knowing that the probability is 2/3?

How many times must you simulate or play the game in order to be ninety-five percent confident of predicting the probability of winning the car: 1) if the contestant has decided to switch? 2) if the contestant has decided not to switch?

2007-01-28 05:27:09 · 2 answers · asked by Colique 2 in Mathematics

Styrofoam has a density of 300 kg/m^3. What is the maximum mass that can hang without sinking from a 40-cm diameter styrofoam sphere in water? Assume the volume of the mass is neglible to that of the sphere.

I've tried using the formula: density = m/V... but got nowhere with it... please help.

2007-01-28 05:26:36 · 1 answers · asked by yaochiemchao 1 in Physics

in order to determine the velosity of an object you should take?
a. distance divided by time
b. time divided by distance
c. distance times time
d. distance + time

2007-01-28 05:26:27 · 7 answers · asked by tico 1 in Engineering

okay, i am in an algebra class in ninth grade high school. i used to fly through my work, i really understood it. but after coming back from winter break, i couldnt do any of it. im really struggling and nobody will help me. so im turning to you guys. i dont want answers to my homework, i just want to understand. one of my problems is 25x+30=15x i guess you have to find out what x equals to solve the problem. im really blanking out so, can you help me?

2007-01-28 05:24:26 · 23 answers · asked by forevr.lonely 1 in Mathematics

2007-01-28 05:23:24 · 8 answers · asked by mark b 1 in Geography

2007-01-28 05:23:07 · 2 answers · asked by jessika 4 in Zoology

2007-01-28 05:22:50 · 1 answers · asked by Aldo 5 in Engineering

2007-01-28 05:22:35 · 12 answers · asked by metriodfan2 2 in Astronomy & Space

2007-01-28 05:21:52 · 2 answers · asked by another</3'dgirl 1 in Physics

2007-01-28 05:20:45 · 3 answers · asked by Anonymous in Chemistry

of the equation and indicate whether or not it is a function

x=ysquared + 9


can you please show work . thank you. and i'm pretty sure you have to set y = to the rest or osemthing like that

2007-01-28 05:19:46 · 2 answers · asked by jackie 1 in Mathematics

What is d limitation of x?

This is what I have done:
1)Obviously: x>=0

2)consider: 0<=x^2<1 , Then: 0<=x<1
so: [x]-[x^2]=0 ---> D1: [0,1)

3)Consider:1<=x^2<2 , Then; 1<=x<2^(1/2)
so: [x]-[x^2]=0 ---> D2: [1,2^(1/2))

4)Consider: 2<=x^2<3 , Then: 2^(1/2)<=x<3^(1/2)
so: [x]-[x^2]=-1, which is not acceptable

There4 at last, D=[1,2^(1/2))
& f(x)=0

But I want a general solution,if possible,which would be useful 4 solving d same ones.
I mean some thing except considering x in different limitation.Thanx

2007-01-28 05:19:14 · 3 answers · asked by Anonymous in Mathematics

1. Living matter has a carbon-14 activity of 16 counts/min per gram of carbon. What is the age of an artifact for which the carbon-14 activity is 8 counts/ min per gram of carbon

2007-01-28 05:18:52 · 3 answers · asked by Mia16 3 in Chemistry

Use the geometric sequence of numbers 1, 3, 9, 27, … to find the following:
a) What is r, the ratio between 2 consecutive terms?

2007-01-28 05:18:26 · 2 answers · asked by Malissa H 1 in Mathematics

DOES A HUMAN CELL HAVE 46 DOUBLE OR SINGLE STRANDED CHROMOSOME?

Also, in my book, it says that during interphase, the cell replicates its DNA. Does that mean that the number of chromosomes are doubled?

2007-01-28 05:18:15 · 3 answers · asked by Anonymous in Biology

2007-01-28 05:18:12 · 7 answers · asked by margaret p 1 in Earth Sciences & Geology

2007-01-28 05:16:25 · 4 answers · asked by Michael L 1 in Chemistry

2007-01-28 05:15:25 · 8 answers · asked by player9900 2 in Astronomy & Space

I have recently designed a new type of motor that can operate on small or large scale. It is clean and uses no fuel!! The only problem is I have no idea what to do with it or get my idea out. I have the basic premise for the blueprints, but I need a little help with the exact specifications. It will work, but the measurements need to be detailed still. I would gladly share credit with someone because I know there would be plenty of credit to go around. I don't have the resources to actually produce a prototype, but the science is sound. Anyone have any ideas on what I can do? I don't want to get ripped off, but I realize that this project is too large for me to do alone.

2007-01-28 05:15:18 · 12 answers · asked by Anonymous in Engineering

Anyone knows of any natural distaster caused by human undeground infrastructure? For exemple, a city collapsing because of the underground structure.

2007-01-28 05:14:40 · 2 answers · asked by kiba_gaara 1 in Engineering

multiplying polynomials

2007-01-28 05:10:55 · 4 answers · asked by Anonymous in Mathematics

2007-01-28 05:08:27 · 6 answers · asked by tico 1 in Physics

i have the coordinate of the initial point and i have the coordinate of the mid point, how do i find the end point. heres the coordinates (2,6) and (-1,1), whats the nd line coordinate? there is a formula for this i just can't find it in my notes, plz help me out..

2007-01-28 05:07:18 · 8 answers · asked by jon f 4 in Mathematics

I'm not experimenting this, but I just need to know how many batteries I need or how many wraps of wire I need.

2007-01-28 05:05:58 · 3 answers · asked by brandon c 1 in Physics

if f(x)=x^2
then what is
1) f(x-a)
2 f((x/2)-1)

please help!

2007-01-28 05:05:55 · 3 answers · asked by Anonymous in Mathematics

Under regular conditions, euglena gracilis is elongated. In some texts i read that euglena gracilis at its resting state would look like a flattened cyclinder...which one is it? Is euglena gracilis supposed to be elongated or a flattened cylinder??? also, what does euglena contracted look like? Is it similar to how euglena encysted looks like? When euglena forms a cyst, must it first be contracted, then form a cyst, which is round?? please help, thank you.

2007-01-28 05:04:17 · 1 answers · asked by Tally 2 in Biology