Science & Mathematics - 20 October 2007

∫1/(x^2+r^2) dr^2

help much appreciated .. =)

2007-10-20 07:40:49 · 3 answers · asked by xoom 2 in Mathematics

a librarian does 8J of work to stack 5 identical books on top of each other. if each book has a thickness of 4 cm, wat is the mass of the book?

Answer: 2 kg

plz help and show steps

thx

2007-10-20 07:40:37 · 2 answers · asked by Anonymous in Physics

Our spirit guides, do they watch Movies and TV when we do
because if we're just sitting there watching TV they might watch it too

2007-10-20 07:36:41 · 9 answers · asked by Anonymous in Paranormal Phenomena

I don't need the answer to this question but credible articles/sources that would explain it

2007-10-20 07:36:07 · 1 answers · asked by ketchup02145 2 in Biology

Alright, here is the question. I'll tell you how far I've gotten trying to figure it out.

"A rifle with a weight of 40 N fires a 5.0 g bullet with a speed of 230 m/s.
(a) Find the recoil speed of the rifle.
(b) If a 600 N man holds the rifle firmly against his shoulder, find the recoil speed of the man and rifle."

The formula I've been attempting to use for recoil velocity of the rifle is m1v1(i) + m2v2(i) = m1v1(f) + m2v2(f)

Wouldn't the entire left side be equal to zero, as both the initial velocity of the rifle and the bullet are zero?

On the right side, I've plugged in m1 = 40N, v1 = ?, m2 = .005 kg (mass of bullet conv. to kg), and v2 = 230 m/s. Solving for v1(f) where the left side has a value of 0, I get the answer -.02875 m/s (recoil velocity of the rifle). This is coming back wrong. What am I missing? Am I even using the right formula? Thanks!

2007-10-20 07:32:28 · 3 answers · asked by justme 4 in Physics

my homework wants me to graph a logarithm..but how do you graph those it's got a number that is sub like log2(x+2) but the 2 after the log is below if you know what i mean how do you input that??

2007-10-20 07:31:16 · 1 answers · asked by kyubinarutokun 2 in Mathematics

if all cats are dogs and all dogs are birds, then all cats are definetely birds! u think this sentence is logically true?

2007-10-20 07:30:52 · 13 answers · asked by .:::Niko:::. 7 in Zoology

2007-10-20 07:29:42 · 1 answers · asked by Anonymous in Engineering

Two balls are thrown upwards from the edge of a cliff 432 ft above the ground. The first is thrown with an initial velocity of 48 ft/s and the other is thrown a second later with an initial velocity of 24 ft/s. DO the balls ever pass each other ?

2007-10-20 07:26:13 · 2 answers · asked by zatz da one 1 in Mathematics

Find the exact values of the following, in surd form form where necessary:

a) sin TT

b) tan TT/4

c) sin 3TT/4

ps. TT is supposed to be pi

2007-10-20 07:25:15 · 8 answers · asked by Anonymous in Mathematics

2007-10-20 07:17:16 · 1 answers · asked by Kevin P 1 in Other - Science

Consider the two equations:

a = k(m)^-1

and

b = k(m)^1

What does "k" equal and how do you find it?

2007-10-20 07:17:00 · 3 answers · asked by Young Einstein 3 in Mathematics

AB {ll (parallel to)} DE. Prove‘angle’ABC + ‘angle’BCD =180 + ‘angle’CDE
http://img102.imageshack.us/img102/1672/newbitmapimagemi5.png

Prove:AB { ll (parallel to)} EF
http://img134.imageshack.us/img134/1913/newbitmapimagevy2.png

Find value of x.
http://img412.imageshack.us/img412/774/newbitmapimageel8.png

‘angle’DFP, ‘angle’ EDQ & ‘angle’ FER are exterior angles of ‘triangle’ DEF. Prove: ‘angle’DFP + ‘angle’ EDQ + ‘angle’ FER = 360
http://img266.imageshack.us/img266/3655/newbitmapimagepk8.png

BD & CD are angle bisectors of ‘angle’ ABC &‘angle’ACE respectively.Prove ‘angle’ BDC=½ ‘angle’BAC
http://img86.imageshack.us/img86/8948/newbitmapimagenm9.png

PT (perpendicular to) QR & PS bisects ‘angle’QPR. If ‘angle’ Q = 65 & ‘angle’ R = 33. Find ‘angle’ TPS
http://img503.imageshack.us/img503/4818/newbitmapimage2vm6.png

ABCD & BPQ are lines.BP=BC & DQ {ll(parallel to)} CP.Prove CP=CD & DP bisects ‘angle’CDQ
http://img249.imageshack.us/img249/498/newbitmapimage2ax1.png

2007-10-20 07:15:57 · 2 answers · asked by friend s 1 in Mathematics

A) manned mission to Mars
B) placing a telescope on the moon to discover, catalog and track near earth objects withouth atmospheric interference?

2007-10-20 07:15:47 · 7 answers · asked by . 3 in Astronomy & Space

What is the strengh of surface tention and how do you know this. please list reasource.

2007-10-20 07:15:04 · 3 answers · asked by GUY 2 in Other - Science

To the NEAREST HUNDREDTH, solve 4 (5 - x) = 8 (x - 10).

i got 8.3 as my answer. but the teacher says i got it wrong.......... so plz tell me HOW u got ure answer.

2007-10-20 07:12:57 · 6 answers · asked by xOXoXox 3 in Mathematics

If two sides of a triangle are 8 and 22, what is the range of possibilities for the third side?

a)14
b)8
c)4
d)12

2007-10-20 07:12:30 · 6 answers · asked by Anonymous in Mathematics

If two sides of a triangle are 5 and 8, the third side could be

a)3

b)6

c)13

d)17

2007-10-20 07:09:51 · 7 answers · asked by Anonymous in Mathematics

2007-10-20 07:08:22 · 2 answers · asked by Felicia B 1 in Mathematics

2007-10-20 07:06:04 · 17 answers · asked by ruhani suneja 1 in Geography

Which of the following theorems is stated: The sum of the measure of the angles in a triangle is 180 degrees?

a)Triangle Sum Theorem

b)Triangle Exterior Angle Theorem

c)Isosceles Triangle Theorem

d)Triangle Inequality Theorem

2007-10-20 07:00:53 · 5 answers · asked by Anonymous in Mathematics

When I see the word "scientific" or "prove" my bullshit filter notices that right away; example: "We used scientific instruments to prove that ghosts are in the house". Another common method is to incorrectly imply that A proves B; example: "We found postive ferrite ions in the soil at the crop circle. This proves that people could not have created it."

What other ways do you use to determine if a "scientific" article is written by a kook?

2007-10-20 07:00:23 · 14 answers · asked by Hgldr 5 in Other - Alternative

1) A vector 5 cm long at 45 degrees. Find horizontal and vertical components graphically. Express as vectors (+/- for direction and X or Y with length and units).
2) What is resultant of vector 30 m/s East and 40 m/s south? (remember angle and magnitude)
How could Pythagorean theorem apply to number 2?

How do I do this?

2007-10-20 06:58:06 · 3 answers · asked by rockchick 2 in Physics

if 2x+4=y and y=3x-6, then 2x+4=3x-6

2007-10-20 06:57:55 · 4 answers · asked by Nat 1 in Mathematics

if 2 lines do not intersect then they are parallel

2007-10-20 06:55:57 · 10 answers · asked by Nat 1 in Mathematics

geometry help plz!!!!

2007-10-20 06:53:00 · 1 answers · asked by Nat 1 in Physics

g(x)=x^2-2x-15

2007-10-20 06:50:11 · 2 answers · asked by Anonymous in Mathematics

want to know the position of the zodiac signs and the position of the moon and stars on Dec 21, 2012. I cannot find an almanac that goes that far in the future

2007-10-20 06:49:56 · 3 answers · asked by what was lot's wife name? 1 in Astronomy & Space

2007-10-20 06:47:36 · 4 answers · asked by chris l 1 in Earth Sciences & Geology

2007-10-20 06:47:21 · 16 answers · asked by Anonymous in Mathematics