# Posts by Andrea

Total # Posts: 851

**science**

If 2.7 moles of copper metal was deposited from a solution of Cu(NO3)2, how many electrons were involved?

*April 18, 2013*

**Physics**

An electric force of 3x10^-8N is produced from an electrostatic point charge of 4x10^-10. It is 40cm from another electrostatic point charge. What is the charge of the second point?

*April 11, 2013*

**Physics**

If an electric force of 550N is produced from two charges, one is 345C, the other is 125C. How far apart are the charges?

*April 11, 2013*

**math**

A jara has 25 green grapes and 75 purple grapes. what is the probability that a purle grape will be chosen at random?

*April 3, 2013*

**Physics**

You are standing on a beach and 5 wave crests land on shore in 50 seconds. Each wave is 32m apart. Find Frequency, period, wavelength and speed.

*April 2, 2013*

**math**

Between which two consecutive integers is the value of this irrational number? square root of 117? A. 8 and 9 B. 10 and 11 C. 14 and 15 D. 20 and 21

*April 2, 2013*

**math**

Max,Owen,Elise, and Cara went to a school carnival. They each played the dart throw,ring toss,water shoot,and basketball throw. Each student won a different game. CLUES:*Max didn't score any points at the dart throw. * Elise correctly tossed 2 rings, but did not win the ...

*April 2, 2013*

**math**

Students submitted pictures for the school yearbook. Only 4/5 of the submitted pictures fit in the yearbook. There were 105 pictures that did not fit. Approximately how many total pictures were submitted for the yearbook? A. 105 B. 210 C. 420 D. 500

*April 2, 2013*

**math**

Emily,Zeke,Harry,& Brook each conducted surveys on the number of books people have in their homes. Then they answered the question below. "MUST ALL MEASURES OF CENTRAL TENDENCY APPEAR AS A NUMBER IN A SET OF DATA COLLECTED? A. Emily says this is always true because all ...

*April 2, 2013*

**math**

Which statement is true? A. All vertical lines have a slope of zero. B. All vertical lines have a slope positive slope. C. All vertical lines have a negative slope. D. All vertical lines have a undefined slope. WHY?

*April 2, 2013*

**math**

A box contains 4 red pencils, 3 blue pencils, and 3 yellow pencils. What is the probability that a student randomly selects a blue pencil, keeps it, then a second student randomly selects a yellow pencil? A. 1/10 B. 3/10 C. 6/10 D. 9/10

*April 2, 2013*

**math**

which shape will create tessellation using only translations? A. scalene triangle B. regular hexagon C. equilateral triangle D. isosceles trapezoid

*April 2, 2013*

**Statistics**

Weights of male mountain lions follow the normal distribution with a median of 150 lb and an interquartile range of 8.2 lb. Find the 75th percentile of the weights. Find the 95th percentile of the weights.

*March 28, 2013*

**Statistics**

An orchestra consists of 25 members. The youngest member is 32 years old. She leaves and is replaced by a new member who is 30 years old. By how much does the replacement change the average age of the members of the orchestra? By how much does the replacement change the median...

*March 28, 2013*

**Circles / Square**

dude steave ur wrong the answer has to be a square root...

*March 25, 2013*

**science**

Who made the first light bulb?

*March 21, 2013*

**Statistics**

How do you find the intercept?

*March 15, 2013*

**Statistics**

That answer is incorrect.

*March 15, 2013*

**Statistics**

A large number of children were surveyed. The table below shows the distribution of the time they spent watching TV in the week before the survey. Intervals include the left endpoint but not the right. You can assume that the times are uniformly distributed within each ...

*March 15, 2013*

**Statistics**

Thanks I got it

*March 15, 2013*

**Statistics**

A class has 3 sections. Here is a summary of the scores on the final exam. Average SD Number of Students Section 1 68 9 20 Section 2 75 9 25 Section 3 60 9 32 Find the average score of all the students in the class.

*March 15, 2013*

**Statistics**

A large number of children were surveyed. The table below shows the distribution of the time they spent watching TV in the week before the survey. Intervals include the left endpoint but not the right. You can assume that the times are uniformly distributed within each ...

*March 15, 2013*

**PHYSICS**

Suppose that the magnetic field in the figure below has a magnitude of 1.1 T, the rod has a length of 0.86 m, and the hand keeps the rod moving to the right at a constant speed of 3.4 m/s. If the current in the circuit is 0.044 A, what is the average power being delivered to ...

*March 14, 2013*

**chemistry**

does Adding A increased Q, so the net reaction proceeds to the left to decrease Q. a+b=ab

*March 11, 2013*

**chemistry**

what mass of ammonium chloride is dissolved in 100 grams water in each of the following solutions in 1.10 molal NH4Cl solution, in a solution which is 75% water by mass in solution with a mole fraction of 0.15 NH4Cl? please help me solve this problem. thank you!

*February 27, 2013*

**Economics**

There are 10 identical consumers whose demand is D: p = 20 - 10q. There are 10 identical firms, each firm's marginal cost is MC(q)= 5 + 5q. The market is competitive. a) derive the market demand function b) derive the market supply function c) what is the market ...

*February 4, 2013*

**Chemistry**

how did you solve it???

*January 19, 2013*

**math**

5(3x+2)+2(3x+2)

*January 13, 2013*

**english**

how do you write a persuasive essay about youny adult women and teen girls quitting abortion.

*January 6, 2013*

**math**

Samantha opened a savings account and deposited some money into the account. The account pays an annual simple interest rate of 5%. After 9 years, the interest earned on the account was $1,800. How much money did Samantha deposit in the account?

*December 30, 2012*

**English- edit my essay please?**

The Great Gatsby Mortality is something we will all face at some point in our life. However, I doubt many people will deal with it in the same light as James Gatz did. He died once in his youth, at the age of seventeen, only to be reborn again as someone entirely new and ...

*December 16, 2012*

**literary**

What does my teacher mean by this? So I'm writing an essay on the great gatsby and I told my teacher about it via emai. (I'm doing online school) and this is what he told me... Also, make sure you develop the theme more than merely "mortality." I always tell ...

*December 16, 2012*

**spanish III check?**

I wasn't sure if the other question posted because I put all the sections into one question and I thought that might have been too much. I'm still not sure how to navigate this site correctly. I mean, I found this question of mine by going through all of the spanish ...

*December 15, 2012*

**spanish III check?**

1. En nuestra casa, mi hermana y yo preparamos la comida los fines de semana y _____ padres la preparan durante la semana.--- NUESTROS 2. Tiene que preparar mucha comida porque tengo cinco hermanos y mis hermanos pueden comerse un millón de enchiladas. ¡...

*December 15, 2012*

**spanish III**

check? I was unsure how to do this part... I still put the answers. Will you correct them if they are wrong and explain to me how to do it right? Thanks! Son las tijeras de nosotros. Son____________ tijeras.Son los gatos de la Sra. Barbosa.---- NOSOTROS Son____________ gatos....

*December 15, 2012*

**spanish**

I gave you everything my teacher gave me... Maybe that's why I'm so confused? Thank you for all your help though! It means a lot. I appriciate it!

*December 15, 2012*

**spanish**

thank you!!

*December 15, 2012*

**spanish**

I have the answers... will you tell me if they're right?? Choose the correct form of the possessive adjective. Modelo: amigos (mi or mis) - mis - amigos is plural Libro- A. SU b. sus 2. Casas A. NUESTRAS b. nuestra 3. Cena a. sus B. SU 4. Sombrero A. TU b. tus 5. Guantes A...

*December 15, 2012*

**algebra**

At a crime scene, police officers find a murder victim in a tub full of warm water. A thermometer shows that the water temperature is 75 degrees F and the air temperature is 70 degrees F. It is known that most people fill a tub with water at 100 degrees F. Find Newton's ...

*December 12, 2012*

**algebra**

In an episode from the TV show Futurama, Phillip J. Fry had $0.93 in his bank account in 2000. In the year 3000 it had grown to $4.3 billion! What was the percent interest rate (to three decimal places) if it had been continuously compounded? What was the percent interest rate...

*December 12, 2012*

**algebra**

Beer cans are right circular cylinders. My Algebraic Ale and Logarithmic Lager cans, from the Schmidt Brewery, have dimensional units called "brewskies". They have a volume (in cubic brewskies) equal to the solution of the number of grams of radium 226 remaining ...

*December 12, 2012*

**algebra**

The radioactive isotope you discovered at 8 a.m weighed 75 mg. You named it "Nerdium." At 3 p.m. it measured only 0.009 grams. What is its half-life?

*December 12, 2012*

**algebra**

At a crime scene, police officers find a murder victim in a tub full of warm water. A thermometer shows that the water temperature is 75 degrees F and the air temperature is 70 degrees F. It is known that most people fill a tub with water at 100 degrees F. Find Newton's ...

*December 12, 2012*

**AP us history**

REALLY?! Man... What's wrong with the others? I was positive they were right.

*December 11, 2012*

**AP us history**

I have the answers will you just tell me if I'm right? This is for my final study guide. The Compromise of 1850 affected which states an/or Territiries? A. Texas, New Mexico, California B. Utah, Texas, California C. CALIFORNIA, OREGON, AND MISSIOUR D. Texas, arkansas, ...

*December 11, 2012*

**math**

Olive Oyl sent Popeye and Wimpy out to get spinach and burgers. They bought the following combination: If the square of the number of burgers is doubled and added to the square of the number of cans of spinach, the total equals 59. When the square of the number of cans of ...

*December 10, 2012*

**Chemistry**

A p-n junction is to be created by diffusing boron (B) into an n-type silicon wafer with an existing carrier concentration of 1015/cm3. The location of the junction will be 6μm below the surface of the wafer. The surface concentration of boron will be maintained at 1020/...

*December 6, 2012*

**Chemistry**

To increase corrosion resistance, chromium is diffused into steel at 980∘ C. If the surface concentration of Cr is maintained constant at 100%, how long will it take (in days) to achieve a Cr concentration of 1.8% at a depth of 0.002 cm below the steel surface? (D0=0.54 ...

*December 6, 2012*

**Chemistry**

A p-n junction is obtained at a depth of 3×10−3 cm by diffusion of antimony (Sb) into p-type germanium. What is the acceptor concentration in the bulk Ge, if diffusion was carried out for three hours at 790∘ C? Given: Constant Sb surface concentration is 8&...

*December 6, 2012*

**Chemistry**

The Gaussian error function can be approximated for small values of x as erf(x)≈x. Suppose a silicon wafer is exposed to aluminum vapor at 1300∘ C. At what distance (in centimeters) will the concentration of Al be 35% of the surface concentration in 164 hours? ...

*December 6, 2012*

**Chemistry**

(a) Certain alloys such as LaNi5 can store hydrogen at room temperature. A plate of LaNi5 containing no hydrogen is placed in a chamber filled with pure hydrogen and maintained at a constant pressure. At what depth from the surface will the concentration of hydrogen be 1/2 the...

*December 6, 2012*

**Chemistry**

You wish to remove nitrogen from the near-surface region of a plate of cobalt which is 1.0 cm thick. The plate is placed in a furnace at 417∘ C where an atmosphere of H2 and NH3 reacts with the nitrogen in the cobalt and fixes the surface concentration to 111 ppm (parts ...

*December 6, 2012*

**Chemistry**

An undesirable consequence of welding steel by acetylene torch is the rise in hydrogen concentration in the metal. That hydrogen contamination embrittles the steel. The metal is typically subjected to a vacuum heat treatment to restore ductility. A steel part is placed in a ...

*December 6, 2012*

**Chemistry**

Carburization" of pure iron (Fe) is carried out at 950∘ C. It is desirable to achieve a carbon content of 0.9% at a depth of 0.1 mm below the surface. A constant supply of carbon at the surface maintains a surface concentration of 1.2%. Assuming the diffusivity of ...

*December 6, 2012*

**geometry**

10 and 2 - 3

*December 6, 2012*

**psychology**

hello, can you help me try to find research for sigmund freud unconscious mind thank you

*December 5, 2012*

**Physics**

There is a door that is 1.0 m wide and can rotate about a vertical axis without friction. The door’s mass is 15 kg and is free to swing open. Someone fires a 10 g bullet at 400 m/s into the exact center of the door, perpendicular to it. Find the angular velocity of the ...

*December 2, 2012*

**Algebra**

a helicopter that is 200 meters above the ground descends at a rate of 2 meters per second. The altitude of the helicopter after t seconds is given by h(t)=2000-2t. 1)give the range of this function 2)give the domain of this function.

*November 27, 2012*

**Algebra**

Joyce combines 9 atoms of hydrogen and 3 atoms of nitrogen to make 3 molecules of ammonia. write a direct variation equation which relates atoms of hydrogen to atoms of nitrogen. How many nitrogen atoms does Joyce need to form ammonia molecules using 51 hydrogen atoms?

*November 27, 2012*

**Algebra**

please help! Noah knows that his friend Ryan uses 2 small chlorine tablets each week to maintain his 10,000 gallon pool: 1)Write a direct variation equation that relates c and g, where c is the number of chlorine talets and g is pool volume in gallons. 2)How many small ...

*November 27, 2012*

**English THE GREAT GATSBY**

1. Fitzgerald creates purpose in Chapter 1. What was his purpose and how does he go about doing it? 7. Write a Gatsby-esque sentence. Make it colorful. My sentence is below... does it make sense? Life to some in New York may seem very Gatsbyesque, what with their tall ...

*November 26, 2012*

**Physics**

A car moving at 43 km/h skids 16 m with locked brakes. How far will the car skid with locked brakes at 129 km/h?

*November 25, 2012*

**math**

rectangle room is 3.75 m by 2.84 m what is the length of the diagonal? how to calcuate?

*November 21, 2012*

**math**

rectangle room is 3.75 m by 2.84 m what is the length of the diagonal? how to calcuate?

*November 21, 2012*

**American History**

1. Believing that truth is what works for actual real people, Harvard psychologist William James developed the philosophy of (A. pragmatism.) B. social progressivism. C. radical progressivism. D. social idealism. 2. Which of the following was true of Secretary of State William...

*November 14, 2012*

**earth**

HELP? Two students are given cubic boxes, measuring 10 cm on a side. Robert puts a single glass marble with a diameter of 10 cm in the box. Susan puts 1,000 1-cm glass marbles in her box. 1.Whose box has more empty space? Explain. 2.Whose box will be heavier? Explain. Can you ...

*November 14, 2012*

**Physics**

35m/s

*November 13, 2012*

**Physics**

Water is flowing through a horizontal pipe at a rate 0.2 m3/s. The pipe narrows from a radius of 10 cm to 4 cm. What is the change in pressure?

*November 13, 2012*

**spanish III**

These are my directions: Change the present tense verb in the sentence to the preterite tense. Can you help me understand how to do this? These are the Questions(1-5): 1. Voy a estudiar. 2. Vas a dar comida al perro 3. Es un estudiante. 4. Somos aquí. 5. Son có...

*November 10, 2012*

**science- geology**

I have to draw a topographical map on poster board of an imaginary island. It must have 2 mountains, 12 MI apart, one with a benchmark of 1510 ft and the other of 1075 ft. We must include 2 streams, one that flows down the larger lake into the ocean, the other must flow in and...

*November 7, 2012*

**math**

express the sum of difference in simplest form 1-1/6-11/18=

*October 29, 2012*

**Physics**

The pulley system shown in the figure is used to lift a 37 kg crate. Note that one chain connects the upper pulley to the ceiling and a second chain connects the lower pulley to the crate. Assume that the masses of the chains, pulleys, and ropes are negligible and the crate is...

*October 25, 2012*

**Gen Chem**

ignition of mgnh4po4*6h2o produces nh3, h2o and magnesium pyrophosphate, Mg2P2O7. complete and balance the equation for this reaction. If 5.00 g of MgNH4PO4*6H2O are ignited, how many grams of Mg2P2O7 would be formed? 2MgNH4PO4*6H2O(g)--->

*October 23, 2012*

**Gen Chem**

I got the answer of 249.6 Is that correct? Thanks for your help!

*October 23, 2012*

**Gen Chem**

what is the formula weight for CuSO4 5H2O?

*October 23, 2012*

**Gen Chem**

epsom salts, household ammonia, and rubbing alcohol are also consumer chemicals that could be used in this experiment. what are the chemical formulas for these substances?

*October 22, 2012*

**Gen Chem**

For my chem class I have 3 elements and have to find what they are used for today or an interesting fact. I have looked but I can't really fin anything. My elements are: Cobalt,Thulium, and Roentgenium I found that cobalt is used in money (nickels, quarters, and dimes, but...

*October 21, 2012*

**Chemistry**

Balance the equation and write the reaction-quotient expression, Qc. U(s) + F2 (g) <----> UF6 (g)

*October 15, 2012*

**Algebra**

How do the solutions of the equation compare to the length of the rectangular object and the x-intercept of the graph? Provide both the solutions and measurement. x^3-10x^2+21x -108 = 0 Length: 9 inches Height: 6 inches Width: 2 inches

*October 12, 2012*

**Algebra II**

Can you make sure my Algebra II work is correct? I've done the problems. I just want to make sure I am right. 1. Write an equation of the line with a slope of 5 and a y-intercept of -3. y=5x-3 2. Write the equation of a line that passes through (9, 3) and has a slope of 2/...

*October 4, 2012*

**Break-Even Analysis**

Given: Jay Letterman has just (year: 2012) become product manager for Avenir. Avenir is a consumer product with a unit retail price of $1.00. Retail margins on the product are 33%, while wholesalers take a 12% margin. Avenir and its direct competitors sell a total of 20 ...

*October 1, 2012*

**algebra**

m=rise/run =18/4 =9/2

*September 30, 2012*

**Finance**

Given: Jay Letterman has just (year: 2012) become product manager for Avenir. Avenir is a consumer product with a unit retail price of $1.00. Retail margins on the product are 33%, while wholesalers take a 12% margin. Avenir and its direct competitors sell a total of 20 ...

*September 29, 2012*

**Ella Minnow Pea**

I read the book Ella Minnow Pea for school... And I actually enjoyed it! But I have to answer some questions about it and I'm not quite sure what I am suppose to be answering. Do you understand these questions better than me? Here they are! Identify the stylistic devices ...

*September 26, 2012*

**us history**

I WILL pass that test. And the class was free so no money was wasted.

*September 26, 2012*

**us history**

I'm not going to drop the class. And due to some personal issues(No not pregnancy)I am taking online school. They did not issue us books therefore I am going in basically blind. Like I said, I'm trying to get a tutor.

*September 26, 2012*

**us history**

Can you help me on this? How consistent were the republican principles applied by Thomas Jefferson and James Madison during their presidencies? How did their policies affect the Federalist Party during Jefferson's and Madison's administrations? I can't find the ...

*September 26, 2012*

**History Help?**

How did the compromises made when writing and ratifying the Constitution encourage the development of political factions? Compare and Contrast the effectiveness of Washington's and Adams' presidencies in obeying and promoting the Constitution during their administrations.

*September 26, 2012*

**us history**

Evaluate the extent to which the Articles of Confederation were effetive in solving the problems that confronted the new nation. Does anywone know where I can find the answer to this? I have to type a whole page on it so I need a lot of information... please and thank you! No ...

*September 26, 2012*

**AP US History**

Well... despite the fact that I am not good at history I did sign up for the class and I AM STICKING WITH IT. I am not going to swtich out. Thank you for your time, however, my descision to stay in the class will not be swayed. I do need help with it however, and I am looking ...

*September 26, 2012*

**AP US History**

How did the compromises made when writing and ratifying the Constitution encourage the development of political factions? Compare and Contrast the effectiveness of Washington?s and Adams' presidencies in obeying and promoting the Constitution during their administrations. ...

*September 26, 2012*

**AP US History help?**

I will do that. Thank you!

*September 26, 2012*

**AP US History help?**

I know this is really long... but I can't figure it out for the life of me. If you don't want to answer the whole question that is fine. I'm greatful for whatever I can get. Also links to websites with the information is also helpful. Thanks!! Directions: Read the ...

*September 26, 2012*

**algebra**

Thank you Steve for your help!

*September 26, 2012*

**Stumped at Algebra II**

How in the world do you do this? I'm so confused. Thank you all for your time and help... -2 < 2x - 5 < 3

*September 26, 2012*

**algebra**

Solve for y, xy + x = -3 How do you do this? I can't seem to come up with the correct answer...

*September 26, 2012*

**algebra**

how do i complete the table with 4x-y=5 x: 0 1, 2 and im trying to find 'y'

*September 26, 2012*

**Algebra**

solve the linear system using substitution 4x - y=5 4x + 4y= -4 Also by using elimination.

*September 25, 2012*

**Chemistry**

How do you convert it to moles of asprin?

*September 23, 2012*

**Chemistry**

Aspirin (C9H8O4) is synthesized by the reaction of salicylic acid (C7H6O3) with acetic anhydride, C4H6O3. 2C7H6O3 + C4H6O3 −→ 2C9H8O4 + H2O When 19 g of C7H6O3 and 19 g of C4H6O3 react, which is the limiting reagent?

*September 23, 2012*