# Posts by Hannah

Total # Posts: 3,347

**chemistry**

Strontium has density of 2.64 and crystallizes with the face-centered cubic unit cell. Find the radius of the strontium atom

**chemistry**

How much heat (in ) is evolved in converting 1.00 of steam at 150.0 to ice at -55.0? The heat capacity of steam is 2.01 and of ice is 2.09 .

**chemistry**

How much heat (in ) is evolved in converting 1.00 of steam at 150.0 to ice at -55.0? The heat capacity of steam is 2.01 and of ice is 2.09 .

**chemistry**

Benzene has a heat of vaporization of 30.72kJ/mol and a normal boiling point of 80.1 C. At what temperature does benzene boil when the external pressure is 490 ? I think I have the equation setup, but I can't figure out how to solve for T2..please help

**statistics**

thank you!!!

**statistics**

calculate the correlation for data set A. Data Set A: xi = 65, 55, 50, 45, 35 yi= 44, 52, 68, 20, 36 I know how to find the mean, variance, standard deviation, and z-score. The part I am having trouble finding is the ZxiZyi. In the chart that I have to fill in it says Zxi in ...

**economics**

What is the role of economic theory in the way economies are run today? I need some concrete examples.

**Statistics(Please help)**

I have a chart that has 4 columns across the top and 33 going down. The colunms on the top read: predicted number, selected number, (col 1 - col2)^2, and the mean of x. Their are 32 predicted numbers and 33 selected numbers. I need to fill in the column that says the mean of x...

**Statistics(Urgent!Please help)**

I have a chart that has 4 columns across the top and 33 going down. The colunms on the top read: predicted number, selected number, (col 1 - col2)^2, and the mean of x. Their are 32 predicted numbers and 33 selected numbers. I need to fill in the column that says the mean of ...

**Statistics**

I have a chart that has 4 columns across the top and 33 going down. The colunms on the top read: predicted number, selected number, (col 1 - col2)^2, and the mean of x. Their are 32 predicted numbers and 33 selected numbers. I need to fill in the column that says the mean of ...

**Statistics**

I have a chart that has 4 columns across the top and 33 going down. The colunms on the top read: predicted number, selected number, (col 1 - col2)^2, and the mean of x. Their are 32 predicted numbers and 33 selected numbers. I need to fill in the column that says the mean of x...

**Chemistry**

yep its right

**maths**

5x10^2 divide by 7x10^4 what is the answer in standard form

**maths**

expand 5(3w^2+4)

**Calculus**

Find the definite integral that represents the arc length of the curve y=sqrt(x) over the interval [0, 3]

**Calculus**

Find the volume of the solid formed by revolving the region bounded by y=x^3, x=2 and y=1 about the y-axis. Please help =(

**Spanish**

How do you say she was looking at the tv in Spanish. I know this is in the imperfect progressive but ver ( to look) is irregular in the imperfect . Does that matter? Would it be esta viendo a la tele?

**chemistry**

Calculate the E° for each of the following reaction. Decide whether each is product-favored in the direction written 2 Cl-(aq) + Cu2+(aq) --> Cu(s) + Cl2(g) i got -1.020 but its wrong and i do not know why.

**chemistry**

From the indicated voltages for the voltaic cell pictured, determine the standard electrode potential, E°M3+/M, if the metal, M, is each of the following. description on the image: in the left beaker there is one Cr3+ and one Cr2+ on the right beaker there is 'M'3...

**Probability NEED HELP**

1. When two fair dice are tossed, what is the probability of a sum of 4 or a sum of 8? 2. When two fair dice are tossed, what is the probability of doubles or a sum over 9? 3. Evaluate 1025! / 1022! Please help

**Probability**

1. When two fair dice are tossed, what is the probability of a sum of 4 or a sum of 8? 2. When two fair dice are tossed, what is the probability of doubles or a sum over 9? 3. Evaluate 1025! / 1022! Please help

**Chem**

2 Ag+(aq) + Fe(s) --> 2 Ag(s) + Fe2+(aq) In which directions do the cations and anions migrate through the solution? cations toward the silver cathode or toward the iron cathode thanks

**Chemistry**

i have a follow up question: In which directions do the cations and anions migrate through the solution? toward the silver cathode ? or toward the iron cathode ? so do the anions(Fe)migrate to the silver? and cations toward the iron? there is a diagram that goes along with ...

**Chemistry**

oh ok i see! thanks!

**Chemistry**

Im having trouble on a question Im not sure what it is they are asking for. A voltaic cell similar to that shown in Figure 20.5 is constructed. One electrode compartment consists of a silver strip placed in a solution of AgNO3, and the other has a iron strip placed in a ...

**Grammar**

Does this sentence make sense, if not how do you write it correctly Never give up to your dreams? Thank you!

**Grammar**

Is the capital word used right in this sentence, if not how can i use it with the same meaning of the sentence His song was SKEPTICAL because it was so good Thank you!

**CHEM**

An atom at the face of a unit cell is shared by how many unit cells? 1 2 4 6 8

**Math**

o ok thank you.

**Math**

1) evaluate: integral of (3x^2 + 5x - 1 + 3/x) dx x^3/3 + x^2/5 - x Is this correct? 2) evaluate: integral of (5e^7x + srqtx) dx I am not sure with this. Could you please explain. Thank you for you help!

**Math**

for number 2 how did you get 2e^2x?

**Math**

1) evaluate integral of xe^3x dx 2) evaluate integral form 1 to 0 of 4e^2x dx I just need help finding the anitderivative. Would it be 2e^2x?

**math**

thank you

**math**

Deifferentiate: y=e^-3x+2 would the answer be -3e^-3x+2 or 3e^-3x+2

**Math(Please help. Thank you)**

thank you

**Math(Please help. Thank you)**

1)evaluate: integral of x ln 4x dx 1/2 x^2 + 2x^2 Is this correct? 6) evaluate the integral from 3 to 1 of x^3 - 3x +1 1/4x^4 + 3/2 x^2 Is this the correct antiderivative?

**Math(Please help. Thank you)**

Is number 3 considered a related rates problem?

**Math(Please help. Thank you)**

Are the rest that I did do correct?

**Math(Please help. Thank you)**

solve the following for x. 1)e^x^2-x=e^2 x^2-x = 2 I am not sure what to do now 2) e^-5x * e^4 = e -5x + 4 = 1 x= 3/5 3) Suppose that the price p (in dollars) and the demand in x(thousands) of a commodity satisfy the demand equation 6p + x + xp =94. How fast is the demand ...

**Math(Please check. Thank You)**

Thank you!!

**Math(Please check. Thank You)**

1) solve:e^x(x^2-4)=0 e^x=0 and then (x+2)(x-2) so x=2, -2 2) differentiate: y=ln(6x^2 - 3x + 1) 1/(6x^2 - 3x + 1) * 12x-3 3) differentiate: y=e^-3x+2 -3 * e^-3x+2 4) evaluate: 2^4-x=8 2^4-x = 2^3 4-x = 3 -x=-1 so x=1 5) differentiate: x^3 + y^3 -6 =0 3x^2 + 3y^2 6) A ...

**Math**

Determine the integral by making an appropriate substitution integral of 8x cuberoot srqt(4x^2-9) dx let u= 4x^2-9 du= 8x dx I do not know what to do now

**Math(Please check)**

evaluate the integral integral of 3 to 2 x/(x^2-2)^2 dx u=x^2-2 du=2x dx 1/2 du = x dx integral of 1/u^2 du -1/(x^2-2) Then I plug in 3 and 2 and subtract them form each other -1/(3^2-2) - (-1/(2^2-2) Is this correct?

**Math(Please help)**

Determine the integral by making an appropriate substitution integral of 8x cuberoot srqt(4x^2-9) dx let u= 4x^2-9 du= 8x dx I do not know what to do now

**Math(Please help)**

o I think I know. Is it because you add 1 to the x^2 which is x^3 and the inverse 1/3 you multiply by 4 to get 12

**Math(Please help)**

Find: the integral (x^2/4 - 4) dx I know that the answer is x^3/12 -4 +c but I do not know how to get this

**Math(Please help)**

Logarithmic differentiation f(x)=(2x-1)^-2 (x+3)^4 at x=1 f'(x)= -2*2/2x+1 + 4*1/x+3 [(2x-1)^-2)(x+3)^4 and then I plug in 1. I am having trouble getting an answer when I plug in 1.

**Math(Please help)**

1) where is the function f(x)= 5 / (2x-4)^3 increasing. I know the answer is for all of x but I do not know how to get this. I know that you can write the equation as 5(2x-4)^-3 2) Let a, b, and c be fixed with a>0 and let f(x)=ax^2 + bx + c. Which of the following ...

**Math(Please help)**

For the first question how did you get 800/64 and 640/64?

**Math(Please help)**

so 0.006(9.30)^2 - 0.02(9.30) + 0.50

**Math(Please help)**

1) h(t)=20(5/8) - 16(5/8)^2 + 10 = 65/4 All I need to know for this is how to calculate the fraction parts to get 65/4. I am not good with fractions. 2) A manufacturer's profit from producing x units of a product is given by P(x)=0.002x^3 - 0.01x^2 + 0.5x. At what ...

**Math(Please help)**

f(x,y)=x^2 e^2x lny (2,1) I need to find the partial derivatives with respect to x and y. I have not idea how to do this especially with the (2,1).

**Math(Please help)**

f(x,y)=x^2 - y^2 a)partial derivative with respect to x. So this means that you hold y^2 constant so would that be 0. So the answer would be 2x? b) partical derivative with respect to y. 2y

**Math(Please help)**

for the first one how did you get (3x^2)?

**Math(Please help)**

Evaluate: f(x,y)=2x^3e^y a) partial derivative with respect to x. I know that you have to treat y as a constant but I have no idea what to do. I do not understand partial derivatives at all. Please help!! b) partial derivative with repsect to y.

**Math(Please check)**

You invest $3000 in a savings account where you earn 4% interest compounded continuously a) what is the formula A(t) for the balance after t years? A(t)=3000e^0.04(t) b) How long will it take for the money to double? 6000=3000e^0.04t Is this the correct setup so far or would I...

**math(Please check)**

Also, solve: ln(x^2-5)=0 take e of both sides x^2-5=1 x^2=6 x=sqrt6 Is this correct?

**math(Please check)**

Find the derivative of the following: 1=x^2+4xy+4y My answer is 2x. Is this correct?

**Math(please check)**

1) Differentiate the following: a) y=(x^3+5x)^6 (x^2+1)^7 (6(x^3+5x^)^5 * 3x^2+5) + (7(x^2+1)^6 *2x) * (x^3+5x)^6 b) y=(x+1)^2 / x^2 (2(x+1)*1) * (x^2) - 2x *(x+1)^2 all over (x^2)^2 Are these correct?

**Math(Please help)**

Would the equation be y-6=15(x-2)?

**Math(Please help)**

Write the equation of the tangent line for the curve y=x^3+3x-8 at point (2,6) Would I take the derivative of the equation and then plug in 2 and then plug everything into y-y1=m(x-x1)?

**Math(Please check)**

ok thank you

**Math(Please check)**

yes, 3b is (pi^2)x. I do not understand why the first derivative is pi^2.

**Math(Please check)**

1) Find the equation of the following lines: A)Through the point (-4,2) and perpendicular to the line y=-1/2x +1 y-y1=m(x-x1) The reciprical of -1/2 =2 So my answer is y-2=2(x+4) or simplified y=2x+10 B)Through the point (1,1) and parallel to the line 5y=15x+25 so y-1=15(x-1) ...

**8th grade physics/science**

assume you are standing on a dock and watching the waves pass directly under where you are standing. You count the number of seconds it takes w1,w2,w3 and w4 to pass directly below you. you determine that all four waves below you in two seconds. info: in the formula the length...

**Food**

How did the Wrigley company come up with the name of orbit gum??

**chemistry**

Thanks!

**chemistry**

Neutralization Reaction Molarity Calculations: For example: What is the molarity of a Ca(OH)2 solution if .032 L of the solution is exactly neutralized by .015 of a 0.56 M HCl? How do I solve- I am unsure where to begin.

**analogy**

arson:crime rose:_________ It must be 7 letters long.

**College math/bus calc**

A rectangular-shaped garden has one side along the side of a house. the other three sides are to be enclosed with 60ft of fencing. what is the largest possible area of such a garden?

**chemistry**

how do i convert delta T to freezing point?

**chemistry**

The molal freezing point constant for water is 1.86 C/m. at what temperature will a micture of 2.00g of CalCl2 and 25.0g of water freeze?

**Math**

I am having trouble figuring out how to do partial derivatives. I have tried practice problems and have read my textbook but I am still so confused. Could someone please explain how to do this? Thank you.

**math**

the expiremental probability that ryan will have math homework on a given school day is 80%.on how many of the next30 school days can ryan expect to have math homework?

**Math-Geometry**

dont you just add all of it and then you put that number on the bottom and then you have the red and green and then you put it on top of the fraction and then multiply and simplify

**english**

so i posted a question very similar to this yesturdya but i have now have a more spesific question. do you guys know any poems about or from the 1950's that talks abuot basic life..

**English**

For a project im writing about 1950's food and the food that was unique to that time. But, in my report i also have to compare a literary work to the information i find on 1950's food. my teacher said the best work would be like a poem, song, article about your ...

**Math(Please help)**

Never mind I got it.

**Math(Please help)**

what would 8^2/3 be. 2^3 = 8 so would it be 2?

**Math(Please help)**

Oh, I see. Thank you

**Math(Please help)**

f(x,y)= 10x^1/3 y^2/3 Compute (27,64) so 10(27)^1/3 * (64)^2/3 10 * (27)^1/3 * (64)^2/3 I know that the answer is 480 but I am having a hard time calculating 27^1/3 and 64^2/3.

**math**

how to solve 2x+3y=17 3x+y=31 then 2(x-3y) y=3x-2 then the last one 2(x+4) x+y=17 please help

**Literature**

ok thank you again!!

**Literature**

so this story is basically about southern humor and story telling correct?

**Literature**

thank you!!

**Literature**

I was wondering if someone could help me find information on the short story "Died and Gone to Vegas" by Tim Gautreaux. I read the story but didn't understand it to well. I was just wondering what the theme is. I tried to look it up but I cannot find any useful ...

**English - Native speakers**

Your toiletries are the things that you use relating to your personal hygiene and grooming. Eau de toilette is the 'perfume' with a higher percentage of water. I get where the confusion came from :) Anyway, hope this helps

**marketing**

Well, if you don't have a clear process of how you develop your new-product you won't be able to measure potential sucess or failure of the product, will you? One example process... Say you have employees draft their ideas (you'd say what they need to include) and ...

**probability and counting**

(1 pt) A box contains 25 yellow, 28 green and 38 red jelly beans. If 13 jelly beans are selected at random, what is the probability that: a) 5 are yellow? b) 5 are yellow and 7 are green? c) At least one is yellow?

**social studies**

what two major political groups make up the Caribbean countries

**Physics**

Two liquids are in a static equilibrium. Water pw= 998 kg/m^3 is in the right arm. Oil in the other. Given l=120mm and d=15mm, what is the density of the oil?

**kind of etymology**

ok so for my etymology class im doing a report and oral presentation on trade names and their etymologies. One of the first things i talk about are how companies or people choose a name for their product or compnay. one of the questions that most companies go by is is it ...

**Literature(Please help)**

I tryed finding information on how to cite a movie in MLA style but I am still confused. I need to cite the movie Smooth Talk by Joyce Chopra. All I know is the name of the movie, director, pg-13 and 1986. Please help. Thank you. Also, I need to cite a journal article. Is ...

**chem- check my answer**

magnesium hydroxide + hydrobromic acid --> is the formula for that Mg(OH)2(s) + HBr(aq) ->H2O(l) +BrOH(s) and are the physical states correct??

**Math(Please help)**

Nevermind, I actually found the answer. It was easier than I thought.

**Math(Please help)**

During weeks in a certain flu season, the rate at which the number of cases of influenza per 100,000 people in a country changed could be approximated by I'(t)=3.298e^0.1044t where I is the total number of people per 100,000 who have contracted influenza and t is time ...

**Economics**

Why does the government try to tackle restrictive practices?

**Geometry**

The area of a regular octagon is 25. What is the area of a regular octagon with sides five times as large as the sides of the first octagon?

**Math**

During weeks in a certain flu season, the rate at which the number of cases of influenza per 100,000 people in a country changed could be approximated by I'(t)=3.298e^0.1044t where I is the total number of people per 100,000 who have contracted influenza and t is time ...

**Economics**

Why is it important for the government to regulate the activities of natural monopolies? Can you name 2 restrictive practices carried out by a company?