Science & Mathematics - 21 September 2007

True or False

2007-09-21 15:30:34 · 3 answers · asked by Anonymous in Physics

Since the dome of the Van de Graaf carries a positive charge, it has an excess of electrons.
True or False

2007-09-21 15:26:54 · 3 answers · asked by Anonymous in Physics

2007-09-21 15:26:31 · 4 answers · asked by Anonymous in Earth Sciences & Geology

They are fractions and please help. Thanks for the last answer.

2007-09-21 15:23:50 · 5 answers · asked by Anonymous in Mathematics

im trying to light my katana on fire but after coating it in somthing flamable the flame goes out when i swing the sword.
i need an idea of what wont go out when i swing it.
or whats the stuff the flame twirlers in hawai put on the sticks?

2007-09-21 15:20:51 · 2 answers · asked by Anonymous in Other - Science

the first time i seen it was at night a dark with a cap on' hoody' not to see its face was realy tall and communicated with me though thougts the second time it was more like a feeling , I was completely acting and answering things I normaly wouldnt do so beond myselve?quit scary the third time i saw blue light every where and from than I lost counting.. it happens all the time,..but i must say the most ( here we go some people will judge me..) when i had a vew drinks or do more.. especially when I am really relaxed ithappens I have seen ''stars in the sky rapid moving have experience things i already had experienced.. and could tell exactly what would happend next.. than i saw blue light bright light came out of my husband eyes? and around him all the colours of the rainbow? I knew exactly what would come next i had a deep respect for animals and nature and a discust fvor humans? religion all made sence all religion we only interpretate all religion wrong

2007-09-21 15:20:39 · 8 answers · asked by Anonymous in Astronomy & Space

If I divide 1.269 cm, calculated from a micrometer to 4 significant figures, by 2 (an exact value), and get 0.6345 cm (4 sig figs, as far as my teacher's concerned), how many sig figs should I round it to?

Should I round it to:
4 sig figs? [no rounding] (multiplication rule)
3 sig figs? (addition rule)

2007-09-21 15:17:35 · 3 answers · asked by Billy E 1 in Physics

A) -a-7
B) -a-3
C) a-4
D) a-7

Can someone help me please? I don't get it

2007-09-21 15:16:20 · 9 answers · asked by Anonymous in Mathematics

Here are some questions I need help with: Please show work and explain in the best detail thanks. Please help me determine a direction for each question aswell.

1. Roget "The Rocker" Clemends can throw a baseball at 140 km/h. If Roger were to throw the ball straight up, determine the following:
a) How high will the ball go, remember that the acceleration due to gravity is 9.8 m/s^2.
b)How long will it take for the ball to reach it's highest point?
c)How long will it take for the ball to come back down?
d)How fast will it be going when it hits the ground?

2. Outside of a certain high-rise apartment building you observed a ball strike the ground at 37 m/s exactly 4.2 s after hearing someone yell "Look out Below!" Knowing that the accleration due to gravity was 9.8 m/s^2, and that each floor is 2.5 m high, which floor do you think the ball was thrown from?

2007-09-21 15:13:45 · 5 answers · asked by Anonymous in Physics

Which of the following animals has a respiratory system that does not rely upon the assistance of the circulatory system?

whale, mouse, carp, grasshopper, or earthworm

2007-09-21 15:12:23 · 2 answers · asked by savemore 3 in Biology

ugh, global. help?

2007-09-21 15:11:49 · 16 answers · asked by jessie 2 in Geography

i no i should of studied but i need the answers bad really bad so can some1 plz help me!!

2007-09-21 15:09:41 · 4 answers · asked by anti-lamesz_SG. 4 in Geography

Can someone guess/describe what I look like, what my name might sound like, what I'm going through by using their natural powers? If yes, then do it. How can I listen to myself more? Be in touch with my mind? Intuition. First impressions.

2007-09-21 15:05:35 · 9 answers · asked by Anonymous in Parapsychology

Or should they be placed under "homework help?"
Should S&M have a "homework help" subcategory?

2007-09-21 15:04:04 · 6 answers · asked by WOMBAT, Manliness Expert 7 in Other - Science

2007-09-21 15:01:08 · 3 answers · asked by S i r i 1 in Medicine

what is that machine you have to stand upright on because its vertical, has two wheels on either side of the base, its battery powered and has a hadle at the top?

2007-09-21 15:01:01 · 3 answers · asked by nursefeelgood 2 in Engineering

its 3 to the negaive 4th power


THANKS

2007-09-21 14:59:51 · 10 answers · asked by crackr 3 in Mathematics

An object is observed to fall from a bridge, striking the water below 3.09 s later.
(a) With what speed did it strike the water?

(b) What was the average speed during the fall?

(c) How high is the bridge?

2007-09-21 14:58:14 · 3 answers · asked by Anonymous in Physics

THANK YOU

2007-09-21 14:57:42 · 4 answers · asked by crackr 3 in Mathematics

In an arcade video game, a spot is programmed to move across the screen according to x = 8.00t - 0.800t3, where x is distance in centimeters measured from the left edge of the screen and t is time in seconds. When the spot reaches a screen edge, at either x = 0 or x = 15.0 cm, t is reset to 0 and the spot starts moving again according to x(t).
(f) When does it first reach an edge of the screen after t = 0?

A motorcyclist who is moving along an x axis directed toward the east has an acceleration given by a = (6.1 - 2.0t) m/s2 for 0 t 6.0 s. At t = 0, the velocity and position of the cyclist are 3.2 m/s and 7.3 m.
(a) What is the maximum speed achieved by the cyclist? (m/s)
(b) What total distance does the cyclist travel between t = 0 and 6.0 s? (m)

2007-09-21 14:56:11 · 2 answers · asked by dunnohow 4 in Physics

I Need to know by Tuesday Please!

2007-09-21 14:53:21 · 3 answers · asked by Anonymous in Weather

2.5 billion years,3.8billionyears,4.6billionyears.

2007-09-21 14:52:12 · 13 answers · asked by Anonymous in Astronomy & Space

A combustion reaction involves the reaction of a substance with oxygen gas. The complete combustion of any hydrocarbon (binary compound of carbon and hydrogen) produces carbon dioxide and water as the only products. Octane is a hydrocarbon that is found in gasoline. Complete combustion of octane produces 8 liters of carbon dioxide for every 9 liters of water vapor (both measured at the same temperature and pressure). What is the ratio of carbon atoms to hydrogen atoms in a molecule of octane?

Ratio is incorrect. Write the balanced reaction equation and apply Avogadro’s hypothesis.

2007-09-21 14:50:23 · 3 answers · asked by Tamra 2 in Chemistry

2007-09-21 14:50:06 · 4 answers · asked by uberifrit 2 in Chemistry

2007-09-21 14:50:04 · 18 answers · asked by harrietshakti 1 in Earth Sciences & Geology

find the integral of x^3 * e^(2x) dx.

2007-09-21 14:49:25 · 3 answers · asked by ! 2 in Mathematics

If two cities are 3km apart, how far apart would they be on the map?

2007-09-21 14:47:51 · 2 answers · asked by Anonymous in Earth Sciences & Geology

please tell me.....

2007-09-21 14:45:52 · 1 answers · asked by TaylorMade85 2 in Mathematics

2007-09-21 14:44:21 · 4 answers · asked by Allyn F 1 in Weather

how does carbon dioxide cause the greenhouse effect and y is a certain amount of carbon dioxide in the atmosphere actually desirable

2007-09-21 14:43:53 · 7 answers · asked by jaktalebojeal 1 in Earth Sciences & Geology