Science & Mathematics - 14 October 2007

Why

2007-10-14 09:29:59 · 5 answers · asked by blueanswers 2 in Mathematics

One of the steps in the manufacture of nitric acid is the combustion of ammonia with oxygen to produce nitrogen dioxide:
NH3+O2→NO2+H2O
How much nitrogen dioxide (in kg) could be produced from 20,000kg of ammonia if the reaction occured in only 72% yield?


Im stuck on this can anyone help me please :)
Thanks soooooo much!

2007-10-14 09:29:32 · 3 answers · asked by Anonymous in Chemistry

2007-10-14 09:29:12 · 2 answers · asked by Anonymous in Chemistry

f(x) = sqrt(3+x)
a = 6
delta(x) = 1

I get delta(f) = 1/2 * 9^(-1/2), but I don't understand how you can get the error since the formula says:
Error: abs( delta(f) - f '(a)*delta(x) )

I keep getting 0 as the error, but I know it isn't correct.

2007-10-14 09:25:10 · 3 answers · asked by Steve waka 1 in Mathematics

How do you know if it's not a spirit wanting you to "think" that's what that person is thinking.? Even if that person is thinking those thoughts..the thoughts might be "coming into their mind" via a spirit and might not be at all what that person really believes or feels.(Hope this wasn't confusing) (This comes from personal experiences)Didn't you ever have a thought come into your head and say, "Where did THAT (thought) come from???"You KNOW it's not YOUR thought.Then , somebody reads your mind & thinks it's YOUR thought,but it's NOT.!!lol (you might need to read this again)lol

2007-10-14 09:24:51 · 12 answers · asked by Deenie 6 in Paranormal Phenomena

1) what is the pH of a solution for which [H+] = 2.4 X 10^-7? is this solution acidic or basic?

2) what is the pOH of the same solution?

3) what is the pH of a 3.0 X 10^-4 solution of NaOH? is this solution acidic or basic?

4) what is the molarity of a 2548 L solution that contains 1.37 g HNO3

5) what is the pH, pOH, [OH-] and [H+] for the last problem?

2007-10-14 09:19:43 · 1 answers · asked by Anonymous in Chemistry

ive just got my head around what 1' and 1" actually mean, after much confusion because of their name. but now i understand what ' and '' actually denote, as in, they are simply the angles subtended in their respective periods of time, i still dont understand where the name arc minutes comes from.

so could somebody please explain how a unit goes from being a name like degrees, then breaks down into arc minutes, arc seconds. why pick these names instead (just examples for illustrating my point here) of millidegrees, microdegrees...???

2007-10-14 09:18:09 · 6 answers · asked by fpa06mr 5 in Astronomy & Space

Is it impossible to convert ml into grams because grams is a unit for weight and ml is a unit for volume?

For example; for Glucose i only know the molecular weight which is 180 g/mol-1 and the volume of solution in which the glucose is in 20ml. I also know in this 20ml solution there is 2.0% of glucose present.

Can i use this information to calculate the weight in grams of glucose or is that impossible??

2007-10-14 09:16:56 · 5 answers · asked by Varisha 6 in Chemistry

2007-10-14 09:15:44 · 6 answers · asked by sue d 1 in Zoology

(sqrt(20x^2 + 5)) / (5x^2)

How do you solve this, i know you use quotient rule, and chain rule, but when i get to (20x^2 + 5)^1/2 x (5x^2)

Please help.

2007-10-14 09:15:30 · 2 answers · asked by Anonymous in Mathematics

Does an individual having brain surgery have something to do with them eventually becoming doctors? or even republicans as well?

2007-10-14 09:14:43 · 4 answers · asked by Anonymous in Medicine

I need a balanced symbol equation for :
Magnesium + hydrochloric acid = magnesium chloride + salt + hydrogen.
I think that's right anyway...If there's any problems please say (:
Kthnx.

2007-10-14 09:11:59 · 1 answers · asked by <3 3 in Chemistry

i am curious about exact technological issues around this issue,NASA monitors its mars exporer and moves it around that planet from here,i cant understand why that technology cant be used here?

2007-10-14 09:11:43 · 8 answers · asked by banthi2003 1 in Astronomy & Space

Is it impossible to convert ml into grams because grams is a unit for weight and ml is a unit for volume?

For example; for Glucose i only know the molecular weight which is 180g/mol-1 and the volume of solution in which the glucose is in 20ml. I also know in this 20ml solution there is 2.0% of glucose present.

Can i use this information to calculate the weight in grams of glucose or is that impossible??

2007-10-14 09:11:00 · 5 answers · asked by Varisha 6 in Mathematics

yeah . would the body be recognisable? In the 1930 s where dna testing was unavailable, how can u recognise a body from a 50 story high fall? would the face be recognisable?

2007-10-14 09:10:04 · 6 answers · asked by Anonymous in Medicine

havent you heard of the "disclosure" project or "fastwalkers".
check them out, enlighten yourselves.

2007-10-14 09:09:33 · 3 answers · asked by Terrybear 1 in Physics

A swimmer is capable of swimming 0.30 m/s in still water.
(a) If she aims her body directly across a 75 m-wide river whose current is 0.60 m/s, how far downstream (from a point opposite her starting point) will she land?
m
(b) How long will it take her to reach the other side?
s

2007-10-14 09:09:04 · 1 answers · asked by kdcheerldr 1 in Physics

thanks for any help you can provide!

2007-10-14 09:08:10 · 5 answers · asked by Anonymous in Mathematics

Does anyone know how much kilowatt-hour a regular lightbulb has and how much money a kilowatt-hour worths? thanks!

2007-10-14 09:07:51 · 2 answers · asked by nicokyu 3 in Engineering

A diver running 1.6 m/s dives out horizontally from the edge of a vertical cliff and 2.9 s later reaches the water below.
How high was the cliff?
m
How far from its base did the diver hit the water?
m

2007-10-14 09:06:28 · 1 answers · asked by kdcheerldr 1 in Physics

1. x=fp both f and p are measured in inches
2. x=7t^3 T is measured in feet
3.x=y/z y is measured in cubic centimeters and z is measured in centimeters
4.x=1/2at^2 A is measured in meter/sec^2 and T is measured in seconds

2007-10-14 09:06:19 · 1 answers · asked by Anonymous in Mathematics

A gas tank with a capacity of 18 gallons is empty. A pump can deliver g gallons of gas every t seconds. In terms of g and t, how many seconds will it take this pump to fill the tank?

2007-10-14 09:06:12 · 3 answers · asked by Harsimar D 1 in Mathematics

A hypothetical planet has a radius 1.7 times that of Earth, but has the same mass. What is the acceleration due to gravity near its surface?

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/20 of its value at the Earth's surface?

Suppose the space shuttle is in orbit 410 km from the Earth's surface, and circles the Earth about once every 92.8 minutes. Find the centripetal acceleration of the space shuttle in its orbit. Express your answer in terms of g, the gravitational acceleration at the Earth's surface.

Thank you

2007-10-14 09:06:00 · 1 answers · asked by Suzumi A 2 in Physics

solve the system of equations.
6x + 2y = 3
3x + y = 2

2007-10-14 09:05:57 · 3 answers · asked by lynne 2 in Mathematics

trigonometric function at t. (4/7, ^/33/7) find sin t.

1. ^/[]33 over7
2. ^/[]33 over4
3. 4^/[]33 over33
4. 4/7

2007-10-14 09:04:40 · 2 answers · asked by dilljam1977 1 in Mathematics

A solid sphere of uniform density starts from rest and rolls without slipping a distance of d = 2.8 m down a q = 29° incline. The sphere has a mass M = 5.8 kg and a radius R = 0.28 m
a) Of the total kinetic energy of the sphere, what fraction is translational?
b) What is the translational kinetic energy of the sphere when it reaches the bottom of the incline?
c) What is the translational speed of the sphere as it reaches the bottom of the ramp?
d) Suppose now that there is no frictional force between the sphere and the incline. Now, what is the translational kinetic energy of the sphere at the bottom of the incline?

I don't know where to start. Please help. Thanks!! :)

2007-10-14 09:02:54 · 1 answers · asked by Anonymous in Physics

2007-10-14 09:01:10 · 7 answers · asked by Anonymous in Astronomy & Space

Hello! I have 3 questions:

A 15 kg uniform disk of radius R = 0.25 m has a string wrapped around it, and a m = 4.6 kg weight is hanging on the string. The system of the weight and disk is released from rest.
a) When the 4.6 kg weight is moving with a speed of 1.3 m/s, what is the kinetic energy of the entire system?
b) If the system started from rest, how far has the weight fallen?
c) What is the angular acceleration at this point?

I don't know how to start. Any help/ideas? Thanks :)

2007-10-14 09:00:18 · 1 answers · asked by Anonymous in Physics

2007-10-14 08:58:44 · 3 answers · asked by jordanx1977 2 in Mathematics

2007-10-14 08:58:13 · 2 answers · asked by Melanie 1 in Chemistry