Saturday

October 1, 2016
Total # Posts: 808

**Chemistry**

NF3 and PF5 are stable molecules. Write the electron-dot formulas for these molecules. On the basis of structural and bonding considerations, account for the fact that NF3 and PF5 are stable molecules but NF5 does not exist

*March 23, 2011*

**Algebra**

why is 5^0=1 Not understanding it. also can you explain when (-3)^n is positive and when it is negative.

*March 14, 2011*

**chem 1**

Using equation: 2Fe(OH)3 + 3H2SO4 -> Fe2(SO4)3 + 6H2O Question: How many molecules of H2O can be made from 9.21 x 10^22 molecules of H2SO4?

*March 1, 2011*

**high school chem 1**

Equation: 4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g) question: What volume of NH3 is needed to react with 71.6 liters of oxygen?

*March 1, 2011*

**High School chem 1**

2Fe(OH)3 + 3H2SO4 -> Fe2(SO4)3 + 6H2) Question: How many molecules of H2O can be made from 9.21 x 10^22 molecules of H2SO4?

*March 1, 2011*

**High school chem 1**

Hi I put the wrong equation up should read 4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g) Question then is what mass of H2O is produced from 350 liters of NH3?

*March 1, 2011*

**High school chem 1**

4NH3(g) + 5O2(g) -> 4NO(g) + 6H20(g) what mass of H2O can be produced from 350 liters of NH3?

*March 1, 2011*

**high school chem 1 **

The above equation has the wrong question attached it should read: How many molecules of H2O is made from 9.21 x 10 (to 22nd power) molecules of H2SO4?

*March 1, 2011*

**high school chem 1 **

2Fe(OH)3 + 3H2SO4 -> Fe2(SO4) + 6H2) How many molecules of H2O can be produced from 350 liters of NH3?

*March 1, 2011*

**math**

an experiment consists of rolling a fair die until it lands on two. What is the probability that it will land on at least two is

*February 28, 2011*

**geometry**

the angle of depression from d to f measures 10 degrees. if df equals 300m, find df. round to the nearest tenth.

*February 18, 2011*

**Lit/chem**

What is a acrostic for the element cesium

*February 15, 2011*

**physics!**

A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum and collect at the ...

*February 14, 2011*

**Diffeq**

(e^xy)cos(2x)+x(y)e^xy(cos2x)-(2x)(e^xy)sin2x

*February 11, 2011*

**math**

how do I work the problem d=3.5t

*February 10, 2011*

**Science**

A block of ice of mass M is pulled horizontally with a steady force P against a force of friction F I have to write an equation for the acceleration of the block.

*February 9, 2011*

**calculus**

Consider the function below. f(x) = 4x2 - 5x (a) Find f '(2). (b) Use the answer in part (a) to find an equation of the tangent line to the parabola y = 4x2 - 5x at the point (2, 6). y =

*February 3, 2011*

**English**

So basically one can interpret it as early understand/hint while the inklings can be interpreted as ink relating to writing pen and ink?

*January 28, 2011*

**English**

Early Inklings Short Essay by John Updike. The title, â€œEarly Inklingsâ€ is an example of a pun (a witty play on words that suggest a double meaning) . Explain the pun and the meaning of the title. I don't even know where to start... Also...

*January 28, 2011*

**MAth**

Find the critical numbers, increasing intervals, x-values where f has an inflection point, and where the graph is concave down from the equation f(x)=2x^4-3x^3-10x^2+20

*January 27, 2011*

**math - algebra**

Fran, Dan, and Stan have a total of 194 cards. Fran has 24 more than Dan, but 35 less than Stan. How many do each of them have? I don't know how to set this up. Thanks.

*January 25, 2011*

**MATH**

Dan, Fran, and Stan have 194 cards. Dan has 24 less than Fran, and Stan has 35 more than Fran. How many do each of them have?

*January 23, 2011*

**Math**

Yeah probably, I also dont remember if it was 20435 or 20425 exactly, but it was approximately that.

*January 20, 2011*

**Math**

okay, good, I think i did it right then (it was actually a question on my exam that I just completed, it was the only question I was unsure about)

*January 20, 2011*

**Math**

A university is doing a study to record the growth of mosquitos. There is originally 25 mosquitoes. The growth of the mosquitos is 0.03% every 7 days. How many days until there are 20 435 mosquitos? What I did was use the growth formula A=25(1+0.03)^t to figure out how many ...

*January 20, 2011*

**MATH**

The sides should be proportional if they are similar, thus, since AB corresponds with wx, and Ab is 24 while wx is 16, 24/16=1.5 . So ABCD is 1.5 times bigger than wxyz. the other side is 30, CD, is 1.5x bigger than yz, so find that and get the area by multiplying. or u can do...

*January 20, 2011*

**Chemistry**

Could someone help me with this question? A vinegar sample was analyzed and found to be 5.88% acetic acid by volume. The density of pure acetic acid is 1.409g/ml. What volume of 0.200 M NaOH would be required to titrate a 2 ml aliquot of this vinegar.

*January 16, 2011*

**Math/Trig**

Is the answer y = 21.15sin(pi/6 t + 3)+66.25?

*January 14, 2011*

**us history**

I know i'm a year late but you can talk about how the government subsidized loans and granted land to companies

*January 13, 2011*

**MATH**

yes thank you

*January 12, 2011*

**MATH**

If angle a =22.17 and angle b = 136.5 what is the measure of angle c? Can someone show me how to go about this

*January 12, 2011*

**math**

The oldest brother gets half a candy bar extra.

*January 11, 2011*

**math**

3 darts, 25+19+6=50

*January 11, 2011*

**math**

ABC=495. 495+459=954

*January 11, 2011*

**math**

Gina,thank You For your help. I'll Show my work next time. Thanks for your quick feedback.

*December 18, 2010*

**math**

I'm a different Tyler WATever

*December 18, 2010*

**math**

make up a list of data with the following landmarks: mode:15 minimum:5 median:10 Maximum:20 use at least 10 numbers describe a situation in which these data might actually occur

*December 18, 2010*

**science**

how much energy is required to obtain superheated steam at 115 degrees celcius from 25 grams of water at 10 degrees celcius?

*December 16, 2010*

**free enter**

true or false the assembly line uses a division of labor

*December 16, 2010*

**algebra**

Compute: 7!/6! x 3!2!/(8-1)! express answer as acommon fraction.

*December 16, 2010*

**algebra**

how many cubic feet are in the volume of a round swimming pool which is 16 feet in diameter and 4 feet deep throughout? express answer in terms of pi.

*December 16, 2010*

**algebra**

six people are going to be seated in a row of 8 chairs. how many different ways may they be seated?

*December 16, 2010*

**Algebra**

Four circles with centers A,B,C,and D are mutually tangent. The areas of circles A,B,C, and D are 25pi, 100pi, 16pi, and 225pi respectively. How many units are in the perimeter of quadrilateral ABCD?

*December 5, 2010*

**Algebra**

What is the largest perfect square that divides 64,800?

*December 2, 2010*

**Algebra**

Find the value of x such that the four-digit number x15x is divisible by 18.

*December 2, 2010*

**Grade 11 Physics**

Two kids are on a beach pulling an inner tube. One is pulling at a force of 45N[N] and the other one pulling at 60N[SW]. What is the net force? (I tried to do it by taking the 60N and making a right angled triangle with it, i got 42.43N north and west, then I tried to combine ...

*November 30, 2010*

**Chemistry**

Well definately the more levels you have, the bigger the radius will be. However, also, the more electrons you have in that level, the smaller the radius will become. This is because the force of attraction will become greater between the electrons and the protons. Thus, if ...

*November 30, 2010*

**physics**

F=qvB(sinθ) but sinθ=1 so we can ignore it. We have B =1.5T q=1.6x10^-19 We just need v from our Ke. Ke=1/2mv^2 v^2=2Ke/m Punch in 8.0x10^13J and look up the mass of a proton (1.672x10^27) and solve for v, which turns out to be 3.09x10^7. F=(1.6x10^-19)(3.09x10^7)(1....

*November 23, 2010*

**PHYSICS PLEASE HELP!!!**

Thank you Bob, but even after reading the article, I still don't understand how to obtain the parallel force acting on the block (question b). Can you expand perhaps?

*November 22, 2010*

**PHYSICS PLEASE HELP!!!**

Please someone have mercy this is a test grade and I have no idea what to do ! A force of 200 N is being exerted on a blocki, which has a mass of 10 kg and is on 30 degrees inclined plane. The force is acting up the plane and parallel to it. The coefficient of friction between...

*November 22, 2010*

**Math**

shrtlf wjeyte r

*November 17, 2010*

**english**

in the miracle worker what does it mean when helen touches her own cheeks

*November 16, 2010*

**physics**

if a 700-kg piano us lifted 4.0 meters in 14 seconds, how much power is developed

*November 15, 2010*

**physics**

if a 700-kg piano us lifted 4.0 meters in 14 seconds, how much power is developed

*November 15, 2010*

**English**

I wrote a paper on Beloved, now I am required to do a MLA Documented Research Paper on this topic. I am stuck on how to begin with a Thesis Statement (subject and predicate)

*November 14, 2010*

**math**

4160

*November 8, 2010*

**math**

416

*November 8, 2010*

**Calculus**

The demand function for a product is modeled by : p=10,000(1-(3/3+e^-0.001x) Find the price of the product if the quantity demanded is (a) x=1000 units and (b) x=1500 units. What is the limit of the price as x increases without bound?

*November 7, 2010*

**Calculus**

The demand function for a product is modeled by : p=10,000(1-(3/3+e^-0.001x) Find the price of the product if the quantity demanded is (a) x=1000 units and (b) x=1500 units. What is the limit of the price as x increases without bound?

*November 7, 2010*

**Physics**

how much work is required to lift a 98-N block of ice if A) it is lifted a vertical distance of 5-m.? B) you push the same block of ice up a 7-m long ramp using in acompare to the work required in b.? C) How does the work required in A compare to the work required in B.? D) ...

*November 7, 2010*

**math**

How does a Hawaiian Baritone laugh?

*October 27, 2010*

**Physics**

The passengers in a roller coaster car feel 50% heavier than their true weight as the car goes through a dip with a 20 m radius of curvature. What is the car's speed at the bottom of the dip?

*October 27, 2010*

**physics**

well,his horzontal speed is all he has at the peak, so vertical speed at launch is vi^2=32^2-29.8^2 solve for Vi Then for height, Vi^2=2*g*h solve for height

*October 23, 2010*

**physics**

An ice hockey puck slides along the ice at 12m/s. A hockey stick delivers an impulse of 4.0kg*m/s causing the puck to move off in the opposite direction with the same speed. What is mass of puck?

*October 17, 2010*

**Physics**

Weight is a force, and as described by Newton's Second Law, F=ma, where m=mass and a=acceleration. At sea level on Earth, the acceleration is 9.81m/s down, which is the pull of gravity. By taking the object up to the top of a high mountain, it will be less affected by the ...

*October 13, 2010*

**6th grade**

I need to know what is the answer to this __ is a set of beliefs, values, and practicest that a group of people share.

*October 8, 2010*

**Algebra 1**

25% of what is 28?

*October 7, 2010*

**geometry**

A, B, and C are collinear, AB = 5x - 19, and BC = 3x + 4. Find an expression for AC if B is between A and C.

*October 4, 2010*

**6th grade**

WHAT IS THE GREENHOUSE EFFECT???

*October 3, 2010*

**business**

C.

*September 28, 2010*

**sociology**

does diamond hurt the enviroment and do we choose profit over ou enviroment when it comesto diaond mining.

*September 14, 2010*

**home economics**

how are patterns applied to fabric?

*September 7, 2010*

**chemistry**

A hydrogen Atom makes a transition between two energy states and emits a photon with a wavelength of 434.2nm. What is the frequency? Does anyone know how to do this?

*September 3, 2010*

**physics**

Speed is a general answer, velocity is what you're looking for

*August 13, 2010*

**Calculus II**

Determine whether the sequence converges or diverges. If it converges, find the limit. An=((-2)^n)/n!

*July 29, 2010*

**physics**

a. f=(G*m1*m2)/r^2 =(6.67x10^-11*.7*70000)/2.1^2) =7.4*10^-7 N b. f=(G*m1*m2)/r^2 =(6.67*10^-11*.7*70000)/1^2 =3.29*10^-6

*July 16, 2010*

**Physics 121 HW**

0.283

*July 14, 2010*

**3rd grade math**

name one interesting thing you learned aboutyour new techer

*June 6, 2010*

**Science-8th**

How do balance the equation:C5H12 + O2---> CO2 + H2O

*June 5, 2010*

**physics**

An electric iron has a resistance of ohms. How much heat energy is produced in 10 minutes if the current passing through the device is 10 amps?

*May 16, 2010*

**math**

How does a 4th grader draw a picture to support this answer?

*May 13, 2010*

**6th grade science (physics)**

explain and describe Law of Universal Gravitation in relation to force, mass and distance

*April 18, 2010*

**oscillation**

An object with mass 0.250 kg is acted on by an elastic restoring force with force constant 10.8 N/m. The object is set into oscillation with an initial potential energy of 0.150 J and an initial kinetic energy of 6.00×10−2 J. What is the amplitude of oscillation? ...

*April 15, 2010*

**Calculate the oscillation frequency f of the H2 mo**

When displaced from equilibrium by a small amount, the two hydrogen atoms in an \rm H_{2} molecule are acted on by a restoring force F_{x}=-k_1 x with k_1 = 510 N/m. Calculate the oscillation frequency f of the H2 molecule. Use m_eff = m/2 as the "effective mass" of ...

*April 15, 2010*

**Physics**

How do you find the phase constant of the oscillation on a graph.

*April 15, 2010*

**Pre Calculus**

Establish the following identity tan(x+pi/4)=1+tanx/1-tanx

*April 15, 2010*

**Pre Calculus**

Establish the following identity sin 2x/sinx - cos2x/cosx = secx

*April 15, 2010*

**Pre Calculus**

Establish the following identity Sin2x/1+cos2x=tanx

*April 15, 2010*

**math**

Suppose 100 dots are arranged in a square 10 × 10 array, and each dot is colored red or blue. (a) Prove that this array must contain a “monochromatic” rectangle. That is, no matter how the red and blue colors are assigned, there must be either a set of four red...

*April 15, 2010*

**Science**

what are ways plants can conserve water

*March 30, 2010*

**4gr math**

12*12

*March 18, 2010*

**algebra**

what is 3y(7y - 6) + 16y simplified

*March 16, 2010*

**algerbra**

f(X)=(x+1)2 that squared

*March 13, 2010*

**phsycis**

First you need to calculate the PE needed to make the climb. U=mgh U=(62*(2600-3700)*9.8) This value is energy or work denoted as a Joule. A Watt= Joule/Seconds So simply take your joules and divide it by the time the trip took. Convert your 5hr to seconds so... W=(62*(2600-...

*March 2, 2010*

**Chemistry**

What mass of CO2 could be absorbed by 1.34 g of CaO?

*February 28, 2010*

**PHYSICS**

A concert loudspeaker suspended high off the ground emits 35 W of sound power. A small microphone with a 1.0 cm2 area is 50 m from the speaker. (a) What is the sound intensity at the position of the microphone? (b) How much sound energy impinges on the microphone each second?

*February 25, 2010*

**Trigonometry**

1) Find the coordinates of the point (-1,3) after the transformation T (to the -3,2 power) 2) What are the coordinates of point (-3,4) under D (to the 3rd power)? 3) Which of the following transformations could map the point (1,2) onto the point (3,6)? a)T (to the 2,3 power) b...

*February 24, 2010*

**Trigonometry**

1) If P'(2,-6) is the image of point P after the dilation D(to the 2nd power), what are the coordinates of point P? 2) A transformation maps (x,y) onto (x+2, y-1). Find the coordinates of A', the image of point A(-2,6) under the same transformation.

*February 24, 2010*

**Trigonometry**

A translation maps (-6,2) onto (-4,-2). Find the image of (3,5) under the same translation.

*February 24, 2010*

**spanish**

1.¿Va a viajar a Perú tu primo Andrés?

*February 23, 2010*