Science & Mathematics - 4 December 2007

explain thorougrly

2007-12-04 09:40:56 · 3 answers · asked by rays2567 1 in Earth Sciences & Geology

How many moles of O2 are present in 44.8L of O2 at STP?

How many moles of CO2 are present in 4.00L of CO2 gas at STP?

What volume in liters is occupied by 2.5 moles on N2 at STP?

2007-12-04 09:40:53 · 4 answers · asked by Anonymous in Chemistry

My dad works for telus and I need humourous jokes, quotes and pictures that he may find amusing for a craft I'm doing for him for Christmas. He works with something to do with toll free calling. Please nothing dirty!! Thank you so much. Geeks rule the world!!!

2007-12-04 09:40:32 · 14 answers · asked by kitKat 4 in Engineering

chapter 7 #29
a roller coaster car has a mass of 500 kg when fully loaded with passengers. if the vehicle has a speed of 20 m/s at point a (point a radius 10 meter) what is the force of the track on the vehicle at this point. what is the maximum speed the vehicle can have at point b (point b radius 15 meter) in order for gravity to hold it on the track.

2007-12-04 09:37:57 · 1 answers · asked by patelm61 1 in Physics

2007-12-04 09:35:31 · 3 answers · asked by Anonymous in Earth Sciences & Geology

What are Neils Bohr's theoretical connections between the energy level transitions of an electron and the specific color of a photon in the hydrogen line spectrum?

Please explain the advantages and disadvantages in the modern quantum mechanical model over the Bohr model. Use the following concepts in your answer: Heisenberg Uncertainty Principle, quantum numbers, orbital, sublevel, Hund's Rule, Pauli Exclusion Principle.

There is a greater variation between the properties (both chemical and physical) of the first and second of a group or family in the periodic table than between the properties of the second and third members of the group. Consider as examples either the group containing nitrogen or the one containing oxygen. Select three properties and discuss the variation of these properties to illustrate the generalization expressed in the first sentence of the question.

2007-12-04 09:33:45 · 2 answers · asked by Bollywood Masti 4 in Chemistry

determine if the following measurements produce 1,2 or no triangles. solve each triangle that results.
C=35 degrees
a=18.7
c=16.1

2007-12-04 09:33:39 · 1 answers · asked by looneytoon1_2006 1 in Mathematics

Calculating the negative lift of an after market airfoil, on a car's trunk?
I'm having trouble doing a practice problem for my exam in physics. I have to take measurements on car's inverted airfoil or find some from the internet, Which seem impossible to find.

I need the path over top of the inverted airfoil, under it, and the length of the airfoil.



I then assume the wind is going 50 mph or 100mph while on the highway. - 22.32m/s and 44.704m/s


I need to calculate the velocity under the inverted airfoil, using the same approximation that the wright brothers used ( bernoulli's equaiton?"


From that , calculate the pressure difference between the top and bottom in Pascals. From that, calculate the force in newtons on the airfoil, then to pounds.


Any help would be appreciated, tried to find measurements on an airfoil for a few hours, can't find any. This problem is driving me insane.

2007-12-04 09:33:19 · 1 answers · asked by submsk 2 in Physics

I know some people say you yawn when
your tired but what's the real reason?
And how come when one person yawns
that makes the person next to them yawn too?

2007-12-04 09:32:17 · 9 answers · asked by Anonymous in Biology

A 6.60 kg mass hanging from a spring scale is slowly lowered onto a vertical spring.

1) What does the spring scale read just before the mass touches the lower spring?

2) The scale reads 22.0 N when the lower spring has been compressed by 1.70 cm. What is the value of the spring constant for the lower spring?

3) At what compression length will the scale read zero?


ANY and ALL help is greatly appreciated. Thanks!

2007-12-04 09:30:18 · 1 answers · asked by Anonymous in Physics

cosx cscx=2cosx

2007-12-04 09:27:40 · 2 answers · asked by looneytoon1_2006 1 in Mathematics

2007-12-04 09:26:54 · 4 answers · asked by Murat A 2 in Earth Sciences & Geology

A girl of mass M1 (60 kg) springs from a trampoline with an initial upward velocity (initial velocity = 8 m/s). At height 2 meters above the trampoline, the girl grabs a box of mass M2 (15 kg).

Assume 9.8 is the force of gravity.

The three questions:

1) What is the speed (v-before) of the girl immediately before she grabs the box? (Expressed in m/s)

2) What is the speed (v-after) of the girl immediately after she grabs the box? (Expressed in m/s)

3) What is the max height the girl reaches (this is measured with respect to the top of the trampoline)? (Expressed in meters)


Any and all help is greatly appreciated. Thanks! :)

2007-12-04 09:23:57 · 1 answers · asked by Anonymous in Physics

Why can't the manufacturers keep a decent inventory of these products on hand so there isn't a shortage every time they have a scheduled reactor shutdown?

2007-12-04 09:23:32 · 2 answers · asked by michinoku2001 7 in Physics

i was doing come candy selling and i never turned it to the school so i decided to have some fum with the money. i had to much fun and came home broke. so give me some help here please

2007-12-04 09:21:30 · 10 answers · asked by brebre231 2 in Mathematics

Two ropes are used to lower a 255 kg piano 5.30 m from a second-story window to the ground. How much work is done by T1, T2, and B (in Joules)?

Info about these forces [T1 and T2 are on opposite sides].
T1 has a force of 1830 N and is 60º above horizontal.
T2 has a force of 1295 N and is 45º above horizontal.
B has a vertical force of 2500 N.

Absolutely ANYTHING will help. Thanks!

2007-12-04 09:18:40 · 1 answers · asked by Anonymous in Physics

a. IgM
b. IgA
c. IgD
d. IgE
e. IgG

2007-12-04 09:18:34 · 2 answers · asked by Anonymous in Biology

It wouuld be best if it was the smallest possible function

2007-12-04 09:16:00 · 2 answers · asked by confused human 1 in Mathematics

i had to do a lab for this and everything, i have the results too. however i need some background information... does any one a good source for this?

2007-12-04 09:15:27 · 3 answers · asked by supahhtroopahh2 3 in Biology

chapter 8 #20
a 15 meter, 500 newton uniform ladder rests against a friction less wall making an angle of 60 degrees with the horizontal. find the horizontal and vertical forces exerted on the base of the ladder by the earth when an 800 newtons fire fighter is 4 meter from the bottom. if the ladder is just on the verge of slipping when the fire fighter is 9 meter up, what is the coefficient of the static friction between ladder and ground

2007-12-04 09:08:10 · 2 answers · asked by Don 1 in Physics

i am making a car for physics but the car can only weigh a certian amount. If the car is going to be rolled down a ramp where would be the most effective place to put most the weight? The front or back?

2007-12-04 09:05:41 · 2 answers · asked by Tony 1 in Engineering

I would prefer a Math teacher to answer this question but anyone who understands how to answer my question is welcomed to answer it as well. I am in eighth grade and I have a research paper due in two weeks. The following are the topics:
-The Monte Carlo Method, Buffon's Needle, and other methods of estimating pi
-Conic Sections and their Equations
-Pascal's Triangle and the Binomial Expansion
-Newton's Second Law and Gravity
-Phi and the Golden Ratio
Please explain each topic in 5 or 6 sentences. I have to choose one of them to do my paper on. So far, it seems to me that Pascal's Triangle is the easiest to understand, but I would like a Mathematician's opinion on this. Thanks!

2007-12-04 09:05:39 · 4 answers · asked by α ρℓα¢є ¢αℓℓє∂ мєℓαи¢нσℓу . 6 in Mathematics

2007-12-04 08:59:05 · 8 answers · asked by AnnaN 1 in Mathematics

How do normal flora help minimize bacterial infections of the skin?

2007-12-04 08:58:27 · 2 answers · asked by Anonymous in Biology

Can anyone walk me with the follow problem please?

A company can manufacture x items at the cost of c(x) dollars, taken r(x) on these items and realize a profit p(x) = r(x) - c(x) dollars (all amounts in thousands)
Find dc/dt, dr/dt, and dp/dt for the following values of x and dx/dt:

a. r(x) = 70x, c(x) = x^3 - 6x^2 + 45/x and dx/dt = .05 when x=1.5

2007-12-04 08:58:20 · 1 answers · asked by Anonymous in Mathematics

a box rests on the back of a truck . The coefficient of ststic friction between box and truck bed is 0.300. When the truck accelerates forward what force accelerates the box. find the maximum acceleration the truck can have before the box slides

2007-12-04 08:57:23 · 2 answers · asked by Don 1 in Physics

Would you more likely go to the past, or future?? And why?

2007-12-04 08:56:38 · 33 answers · asked by Anonymous in Physics

I have a question of my homework that asks "The human body's immune system normally tries to get rid of any foreign matter it encounters ie. bacterial infections. This is also why organ transplants are sometimes rejected.

What prevents a mother's immune system from rejecting the fetus developing inside of her?

I have absolutely no idea so any help would be appreciated.

Thank you!

2007-12-04 08:55:49 · 6 answers · asked by Hello! 3 in Biology

what type of math is used when building a pyramid

2007-12-04 08:54:36 · 4 answers · asked by dumbkid13 1 in Engineering

masses m1= 4 kg and m2=9 kg are connected by a light string that passes over a frictionless pulley. m1 is held at rest on the floor and m2 rests on a fixed incline of theta is 40 degrees. the masses are released from rest and m2 slides 1 meter down the incline in 4 seconds. determine the acceleration of each mass, the tension in the string and the coefficient of kinetic friction between m2 and the incline

2007-12-04 08:54:16 · 3 answers · asked by Don 1 in Physics