Science & Mathematics - 29 October 2007

For the reaction 2Al + 6HCI3 -> 2AlCI3 + 3H2 how many moles of H2 are produced by the complete reaction of 4.90 moles of Al?

2007-10-29 15:30:46 · 2 answers · asked by Lost 1 in Chemistry

Hey… We were given this problem in class and I am having a difficult time solving/ understanding the question. I tried finding the resultant vector and then proceeding from there but then I got all sorts of awkward answers….

Here’s what I tried to find the magnitude:
√((Magnitude)cos (angle) + (Magnitude2) cos(angle2 ) + (Magnitude)sin (angle) + (Magnitude2) sin(angle2 ))

I then used tan to find the angles but this I believe was incorrect. Could someone perhaps attempt the problem and explain/ show how to do it? Thanks a bunch for your help:)

Here’s the problem:

An airplane with an air speed (speed in still air) of 178 m.p.h. is headed due North (90°). If a west wind (180°) of 20m.p.h is blowing, determine the direction travelled by the place and its ground speed (actual speed with respect to the ground).

2007-10-29 15:29:40 · 2 answers · asked by Anonymous in Mathematics

I remember an article that said people are soon going to be going into outerspace for just a monumental cost. I was just wondering if anyone could find that article, or if they knew how long the people would be staying in those space stations.

2007-10-29 15:29:04 · 3 answers · asked by Gavin 1 in Astronomy & Space

I need to name these compounds:

1. Pb(H2P)2

2. H3P

Other than those two problems, I could solve the rest...

2007-10-29 15:26:46 · 1 answers · asked by dancelikewhaaaat 1 in Chemistry

everyone says if u die in ur dream u die in real life, but i think its true because did u ever notice right before ur about to die in a dream, u wake up all sweaty or dizzy or confused?

2007-10-29 15:25:43 · 9 answers · asked by xzxflyersfanxzx 2 in Other - Science

This is Sylvia Brown's son who is also psychic. What have you heard about him? Have you seen him on tv etc?

2007-10-29 15:24:22 · 12 answers · asked by Deenie 6 in Paranormal Phenomena

science homework =[

2007-10-29 15:23:39 · 6 answers · asked by Anonymous in Biology

2007-10-29 15:23:18 · 3 answers · asked by Beanie 3 in Biology

How are molecular clocks calibrated?

2007-10-29 15:22:58 · 4 answers · asked by Anonymous in Astronomy & Space

a gameboy costs $56.77 it is on sale for 33% you have a coupon for an extra 15% off how much will the gamebo cost

2007-10-29 15:19:40 · 7 answers · asked by Anonymous in Mathematics

List someways an austronaut could keep her supplies from floating away from her while she is in orbit around the earth

2007-10-29 15:18:21 · 2 answers · asked by fabulous! 1 in Astronomy & Space

cuz someone told me he said something like it would be like that movie "butterfly effect" where no matter your intention, something worse would happen...

2007-10-29 15:15:48 · 3 answers · asked by Whole 4 in Physics

hard question. i no the answer 1st person to get it right, gets 10 points!!!! the question is The heat absorbed or released durining a change of state is called ________________. wuts the answer? hurry and answer this question!!!!

2007-10-29 15:13:19 · 6 answers · asked by #1 padres fan 3 in Other - Science

2007-10-29 15:08:49 · 7 answers · asked by Anonymous in Astronomy & Space

f(x)= (x + a)(x - a)

2007-10-29 15:08:39 · 2 answers · asked by MusicLuvr 5 in Mathematics

Classify /_\ABC by its angles when m/_A = 32, m/_b = 85, and m /_C = 63.

2007-10-29 15:07:45 · 4 answers · asked by pkbrauer 1 in Mathematics

Joe bought 1/2 a case of cokes, and gave 1/6 of what he has to Sam.Mary bought 1/3 a case of cokes, and gave 1/4 of what she ahs to Sheila. How many more cokes did Sam have than Shelia?

2007-10-29 15:07:08 · 6 answers · asked by gizzydivenx3 1 in Mathematics

Find a 6 digit number in which the first digit is one more than the third, the the second digit is one less than the fourth, the fifth digit is one less than the third, and the sixth digit is one more than the fourth. the sum of the second and third digit is equal to the first digit. the sum of all the digits 30..................please some one help me with this i have be racking my old brain(31 years old) trying to help my niece with this problem

2007-10-29 15:06:21 · 3 answers · asked by kellissandria 1 in Mathematics

Stopped completely? Or stopped and started to turn in the other direction? Or if it flipped upside down?

2007-10-29 15:06:07 · 22 answers · asked by Lorah 2 in Earth Sciences & Geology

do you think it exsited? why or why not?

2007-10-29 15:05:00 · 8 answers · asked by la 2 in Earth Sciences & Geology

If a ball is thrown vertically upward from a height of 5 ft, with an initial velocity of 80ft/s, its height h after t s is given by . How long does it take the ball to return to the ground?

2007-10-29 15:03:39 · 12 answers · asked by Amanda K 1 in Mathematics

Say I put a large ten pound magnet on a copper flag pole would recieve more lightning than a plain copper flag pole? (I know that flag poles are not copper, just an example!)

2007-10-29 15:00:50 · 3 answers · asked by yoyo 2 in Weather

2007-10-29 14:59:14 · 8 answers · asked by Tonya E 1 in Mathematics

A couple has a female child with phenylketonuria, and 3 unaffected children. Neither parent nor any of the 4 biological grandparents of the affected child has had this disease. The most likely genetic explanation is that phenylketonuria is inherited as a(n) ________ disease.

1. autosomal dominant
2. autosomal recessive
3. sex-linked recessive
4. sex-linked dominant
5. cannont make a reasonable guess from this information

2007-10-29 14:59:03 · 2 answers · asked by Anonymous in Biology

how many people do you think are in the world?

2007-10-29 14:58:57 · 13 answers · asked by Anonymous in Geography

how does it work?
do you take the state of the higher element or the lower?

2007-10-29 14:55:39 · 1 answers · asked by sweetheart 2 in Chemistry

what information can you get from a chemical equation??

simple answer please!!

2007-10-29 14:55:31 · 2 answers · asked by THAT is the question 2 in Chemistry

Galileo the 1500s mathematitian

2007-10-29 14:55:20 · 3 answers · asked by ism 2 in Physics

Can anyone help me with this quesion?
Which one is higher and which one applies during a skidding car?

2007-10-29 14:54:46 · 2 answers · asked by Anonymous in Physics

To estimate the height of a building, a stone is dropped from the top of the building into a pool of water at ground level. How high is the building if the splash is seen 5.6 seconds after the stone is dropped?

2007-10-29 14:51:56 · 1 answers · asked by JerseyGirl 2 in Engineering