Science & Mathematics - 25 November 2007

k the teacher said ROUND ANSWERS TO 2 DECIMAL places so if i have the number 26213.64 or 19150.08 what does that round off to thank you

2007-11-25 14:54:21 · 5 answers · asked by Ash 1 in Mathematics

A 12.0 kg block is dragged over a rough, horizontal surface by a 71.0 N force acting at 20.0° above the horizontal. The block is displaced 5.00 m, and the coefficient of kinetic friction is 0.300. What is the increase in internal energy of the block-surface system due to friction?

2007-11-25 14:49:47 · 1 answers · asked by Anonymous in Physics

Batman jumps straight down into a 500 kg. boat that is going 20 m/s while trying to catch a fleeing villain. The boat then slows to 17 m/s. What is the mass of Batman?

2007-11-25 14:49:14 · 3 answers · asked by yummy_girlscout 1 in Physics

Show that if G is a finite group with identity e and with an even number of elements, then there is a ≠ e in g such that a* a = e.

2007-11-25 14:48:02 · 3 answers · asked by Anonymous in Mathematics

why do matter and anti-matter annihilate eachother. take for example an electron/positron pair. the only difference in the 2 is the charge. why does that mean they would be converted entirely to energy when they come in contact.

2007-11-25 14:45:27 · 6 answers · asked by Anonymous in Physics

Fermentation is a complex chemical process of wine in which glucose in fruit is converted into ethanol and co2
C6 H12 O6 --->2 C2 H5 OH (I) + 2 C02 (g)
Startin with 500.4g of glucose, what is the maximum amount of ethanol (in grams and liters) that can be obatained by the process? (Density of ethanol =0.789g/mL

2007-11-25 14:43:39 · 2 answers · asked by jamie d 2 in Chemistry

so out of the three types of pions one confuses me, π0. its make of an up quark and anti-up quark, or a down quark and an anti-down quark. how does that work? wouldnt they annihilate eachother.

2007-11-25 14:43:27 · 1 answers · asked by Anonymous in Physics

2007-11-25 14:41:55 · 3 answers · asked by Charles T 1 in Engineering

Do you believe in strange and mysterious phenomena such as levitation, telepathy, dowsing, faith healing..?

2007-11-25 14:40:24 · 4 answers · asked by want_to_know 2 in Other - Science

Can anyone tell me all they know about Dinosaurs?like where I can find really awesome pictures,or cool places to visit,how they were formed and how they died,stuff like that.

2007-11-25 14:39:14 · 3 answers · asked by Hardy Girl For Life 1 in Earth Sciences & Geology

hey sorry about the wording. here it is: when a piece of metal oxidizes, which metal out of (aluminum, zinc, iron, and copper) does the oxide layer protect the remaining metal from further damage best. this is for my ap chem test which is due tomorrow, so it would be greatly appreciated if you could help. thanks

2007-11-25 14:38:49 · 2 answers · asked by nick 1 in Chemistry

also, how many molecules of carbon dioxide are produced during the fermentation of one molecule of glucose?

and

how many molecules of ethyl alcohol are produced during fermentation of one molecule of glucose?

2007-11-25 14:37:39 · 3 answers · asked by sportsy 1 in Biology

2007-11-25 14:35:47 · 4 answers · asked by Charles S 1 in Earth Sciences & Geology

The crystal structure of MgAl2O4 contains cubic closest packed anions (O2-) with Al3+ cations in some of the octahedral holes, and Mg2+ cations in some of the tetrahedral holes.
1)What is the number of nearest neighbour oxide ions in the crystal for Al3+?
2)What is the number of nearest neighbour oxide ions in the crystal for Mg2+?

2007-11-25 14:34:35 · 1 answers · asked by Anonymous in Chemistry

we often see birds sitting on high power electric wires but not electrocuted ,while other animals are electrocuted when touched with wires.

2007-11-25 14:33:55 · 9 answers · asked by baloch 1 in Zoology

Let G be a group and let a,b ϵ G. Show that (a*b) ′ = a′ * b ′ if and only if a* b = b*a.

note: ϵ is an element, ′ is prime.

2007-11-25 14:31:49 · 2 answers · asked by Anonymous in Mathematics

This summer around mid-end of june in far north ontario I found groups of 10-20 tiger swallow tails all yellow in semi-dry mud just sort of all together... I was just curious if anyone new what they were doing... mating... eating...? Need for a project please help.

2007-11-25 14:29:04 · 4 answers · asked by kobyskid 1 in Zoology

2007-11-25 14:26:30 · 3 answers · asked by v.j S 1 in Biology

1. The length of time from the formation of a cell until it divides is...
a. mitosis
b. the cell cycle
c. cytokinesis
d.meiosis
e.interphase

2. A nondividing cell is said to be in...
a.interphase
b. prophase
c. metaphase
d. anaphase
e. telephase

3.Cells produced by mitosis have
a. 1/2 the number of chromosomes as the parent cell
b. double the number of chromosomes as the parent cell
c. the haploid number of chromosomes
d. the diploid number of chromosomes

4. Which of the following is not true of synapsis?
a. sister chromotids become joined at the centromere
b. homologous chromosomes pair up
c. crossing over can occur
d. a tetrad forms
e. genetic recombination can occur

2007-11-25 14:15:57 · 3 answers · asked by Brittany B 2 in Biology

2007-11-25 14:15:13 · 13 answers · asked by Anonymous in Paranormal Phenomena

Here's part of what she wanted:

"Types of testing/procedures for pre-pregnancy"

Well I'm doing this project related to genetic disorders, so I guess she meant testing/procedures for genetic disorders.

But I'm confused now. How can you test whether or not a baby has a genetic disorder or not if the baby isn't even there yet? Am I suppose to test whether or the parents or carriers or something similar?

Please help! I'm confused!

Merry Christmas and thanks!

2007-11-25 14:15:02 · 12 answers · asked by UnknownD 6 in Biology

I just thought of this today. In vertebrates, three groups have developed flight, reptiles, birds (I know, I know they're sort of reptiles), and mammals (bats). So why did only one group of arthropods (insects) develop flight? Any one have any info that I'm unaware of, or any theories?

2007-11-25 14:14:58 · 3 answers · asked by Spyderbear 6 in Zoology

2007-11-25 14:14:15 · 11 answers · asked by Anonymous in Paranormal Phenomena

A 7.0 g bullet is fired into a 1.5 kg ballistic pendulum. The bullet emerges from the block with a speed of 200 m/s, and the block rises to a maximum height of 12.5 cm. Find the initial speed of the bullet.
m/s

2007-11-25 14:13:09 · 1 answers · asked by AmandaLiu 1 in Physics

Small rockets are used to make small adjustments in the speed of satellites. One such rocket has a thrust of 55N. if it is fired to change the velocity of a 85000 kg space craft by 93 cm/s, how long should it be fired? answer in seconds.

make sure cm is converted to m/s

2007-11-25 14:10:38 · 2 answers · asked by XzoeyX 2 in Astronomy & Space

I really like this girl soo much and maybe this would be the last birthday gift i will give to her,because im gonna gradute in highschool next year and maybe im not gonna see her again.Please help me.

2007-11-25 14:10:34 · 15 answers · asked by ChrisCT 4 in Astronomy & Space

Let c be a positive number. A differential equation of the form

dy/dt = ky^(1+c)

where k is a positive constant, is called a "doomsday equation" because the exponent in the expression ky^(1+c) is larger than that for natural growth (that is, ky).

a) Determine the solution that satisfies the initial condition y(0) = y_0.
b) Show that there is a finite time t =T (doomsday) such that lim t->T- y(t) = infinity
c) An especially prolific breed of rabbits has the growth term ky^1.01. If 2 such rabbits breed initially and the warren has 16 rabbits after three months, then when is doomsday?

show work/steps plz..thanks!

2007-11-25 14:07:24 · 1 answers · asked by Anonymous in Mathematics

Why are some aquatic animals, especially mammals such as whales, extremely large compared with terrestrial animals?

2007-11-25 14:05:34 · 8 answers · asked by livelaughlove 2 in Biology

1 PbS

2 Co(NO3)2

3 (NH4)2SO4

2007-11-25 14:03:48 · 4 answers · asked by Anonymous in Chemistry

A. K
B. I2
C.Hg
D.Mg

2007-11-25 14:00:43 · 2 answers · asked by Anonymous in Chemistry