Science & Mathematics - 27 September 2007

we depend on shops and stores for food clothing and shelter, but only a few of us really know how to grow plants, make clothes and build houses. if things don't change don't you think 100 yrs or so from now humans would be so dependent on technology they might forget how to grow crops or how to build shelter.? as the years pass by slowly people are forgetting about basic knowledge of living. they are becoming more and more concern in the areas of technology.. wanting to make everything easy and automatic. do you think it is possible for human beings in the future to forget the basic means of survival in nature?

2007-09-27 07:45:57 · 3 answers · asked by loaded 2 in Other - Science

to turn your eletric meter back on

2007-09-27 07:43:31 · 2 answers · asked by myeelnn 1 in Engineering

Radon-222 is radioactive but almost chemically inactive. explain please

2007-09-27 07:43:23 · 5 answers · asked by Anonymous in Chemistry

part 2) factorise 8! - 4 (7!) ; 7!/3!4 + 7!/2!5!

2007-09-27 07:38:02 · 5 answers · asked by astalavista 1 in Mathematics

y = 2 - x
x^2 + 2xy = 3

I know you have to do this:

2 - x = x^2 +2xy -3

but when I try to solve it I always get a quadratic that just can't factorise, help!

2007-09-27 07:34:45 · 5 answers · asked by Anonymous in Mathematics

2007-09-27 07:34:06 · 7 answers · asked by Ivonne G 1 in Mathematics

A cable is lifting a construction worker and a crate, as the drawing shows. The weights of the worker and crate are 971 N and 1450 N, respectively. The acceleration of the cable is 0.620 m/s2, upward. What is the tension in the cable (a) below the worker and (b) above the worker?

2007-09-27 07:29:43 · 2 answers · asked by sweet_dreams 1 in Physics

2007-09-27 07:29:38 · 5 answers · asked by Anonymous in Geography

2007-09-27 07:26:24 · 4 answers · asked by Ivonne G 1 in Mathematics

It obviously happened, since all evidence points to it (CMB radiation, for example) - but what triggered it? Has matter/energy always existed, and in what form? What about time? How did things start, without time? (if that makes any sense at all - I'm probably asking this wrong).

How much of this can I understand without understanding too much about quantum physics?

Where can I find information that addresses the difficult questions, but that I can still follow?

2007-09-27 07:24:34 · 14 answers · asked by Dreamstuff Entity 6 in Astronomy & Space

can only use cylindrical spaghetti and the spaghetti cant be hollow

2007-09-27 07:21:59 · 5 answers · asked by Diego O 1 in Engineering

2007-09-27 07:21:44 · 8 answers · asked by astalavista 1 in Mathematics

Use the diagram to complete the table. Classify each member of the food web as autotroph, heterotroph, and identify the heterotrophs as herbivores, carnivores, omnivores, or saprophytes.


I filled out a few i knew, if there right? Use rabbit, fox, bear, bacteria, grass, and berry bushes as the answers


Autotrophs| Heterotrophs| Herbiv, Carniv, Omniv, or Saprop
1. bacteria
2. grass
3. berry bushes
4.
5.
6.

2007-09-27 07:21:25 · 1 answers · asked by matterized 1 in Zoology

And is this hydrogen flammable?(safety reasons)

2007-09-27 07:17:44 · 3 answers · asked by jamesc9009 1 in Chemistry

Would all animals benefit from extended prenatal care? I know that mammals take care of their young extensively until they mature, but would all other animals benefit from this same treatment if it was given to them? Such as vertebrates...please try and use facts to support answer. Thanks.

2007-09-27 07:12:14 · 3 answers · asked by Anonymous in Zoology

2007-09-27 07:07:11 · 6 answers · asked by searrah m 1 in Mathematics

2..is the earth still forming?

2007-09-27 07:07:06 · 5 answers · asked by Anonymous in Astronomy & Space

(C4H10) + (O2) ------> (CO2) + (H2O)

2007-09-27 07:05:58 · 4 answers · asked by natsyy 1 in Chemistry

2007-09-27 07:04:20 · 2 answers · asked by prime 3 in Chemistry

2007-09-27 07:04:15 · 7 answers · asked by bagua1 5 in Astronomy & Space

With which of the following groups is sodium most likely to form a chemical bond: Alkaline,earth metal,metalloids,halogens, or noble gases? Why?

2007-09-27 07:02:54 · 1 answers · asked by KrAzZiELaOsBoI 1 in Chemistry

and the Oxidation Number for Beryllium

2007-09-27 07:01:32 · 1 answers · asked by KrAzZiELaOsBoI 1 in Chemistry

solve by substitution

3x-4y=x-y+4
2x+6y=5y-4

I tried to work it out on scratch paper, still stumped.

2007-09-27 06:59:31 · 12 answers · asked by Cat C 1 in Mathematics

2007-09-27 06:58:54 · 1 answers · asked by Anonymous in Chemistry

*The cost of 12 oranges and 7 apples is $5.36. Eight oranges and 5 apples cost $3.68. Find the cost of each orange.


*Sam invested a total of $10,000, part at 8% and the rest at 3%. How much was invested at 8% if he earned a total of $600 in one year? (Use the formula , Interest = principal * time * rate)


*In an office there was a small cash box. One day Jane took half of the money plus $1 more. Then Mike took half of the remaining money plus $1 more. Rob then took the remaining $6. How many dollars were originally in the box?


*The sum of two numbers is 8 less than twice the first number. Their difference is 4 less than twice the second number. What is the larger number?

2007-09-27 06:52:33 · 5 answers · asked by Anonymous in Mathematics

X-4(8-4x).

Please explain.

2007-09-27 06:48:33 · 4 answers · asked by ray 1 in Mathematics

2007-09-27 06:48:19 · 2 answers · asked by morningwillowkisses 2 in Astronomy & Space

1: Which substance is readily converted from a liquid to a solid by chemical reaction with hydrogen?
cotton-seed oil
glycerin
kerosene
mercury


2: The ability of a substance to remove oxygen from a compound is called
oxidation
hydrogenation
electrolysis
reduction


3: When passed over hot copper oxide, hydrogen acts as
a catalyst
an oxidizing agent
a reducing agent
a solute


4: Hydrogen can be prepared by reacting cold water with
aluminum
iron
platinum
sodium


5: The safest way to make hydrogen in the laboratory is to add hydrochloric acid to
calcium
iron
potassium
sodium


6: Hydrogen may be formed when steam reacts with hot
copper
iron
mercury
silver


7: The lightest element known is
boron
helium
hydrogen
lithium


8: Hydrogen is
less dense than air and inert
very soluble in water and combustible
odorless and a reducing agent
denser than air and tasteless


9: Hydrogen may be obtained

2007-09-27 06:45:45 · 4 answers · asked by kimberly 1 in Chemistry

Which is an instance of a physical surface which might be used to illustrate the concept of a plane.

Consider two walls that meet in a corner as representing portions of two geometric planes. What geometric shape is formed by the set of points common to the two planes?

Consider three walls that meet in a corner as representing portions of two geometric planes. How many points are common to the three planes?

2007-09-27 06:44:43 · 2 answers · asked by Anonymous in Mathematics

Two crates, of mass m1 = 60 kg and m2 = 110 kg, are in contact and at rest on a horizontal surface (Fig. 4-54). A 620 N force is exerted on the 60 kg crate. The coefficient of kinetic friction is 0.15.

a) Calculate the acceleration of the system.
=............ m/s^2 (to the right)

(b) Calculate the force that each crate exerts on the other.
=.......N

(c) Repeat with the crates reversed.
acceleration =......m/s2
crate force=........ N

2007-09-27 06:40:01 · 1 answers · asked by Nikita 1 in Physics