# Posts by sarah

Total # Posts: 5,805

**AP Chemistry**

Can anyone explain how to find potential of the cell?

**Chem**

Thank you Just one more question Why is it (63.55/2) g Cu ?

**Chem**

Can someone please explain how to tackle this problem? Cu - Anode electrode Zn - Cathode electrode A current of 2 amps is sustained for 16 minutes. what mass of Cu(s) is deposited on the zinc electrode? (Faradays' constant: 96500 C/mol e-)

**chem**

(sorry - accidentally posted it as physics problem) Can someone please explain how to tackle this problem? Cu - Anode electrode Zn - Cathode electrode A current of 2 amps is sustained for 16 minutes. what mass of Cu(s) is deposited on the zinc electrode? (Faradays' ...

**Physics**

Can someone please explain how to tackle this problem? Cu - Anode electrode Zn - Cathode electrode A current of 2 amps is sustained for 16 minutes. what mass of Cu(s) is deposited on the zinc electrode? (Faradays' constant: 96500 C/mol e-) Please and thank you!!

**Probability and statistic**

Suppose X has an exponential distribution with mean equal to 13. Determine the following: (a) Upper P left-parenthesis x greater-than 10 right-parenthesis (Round your answer to 3 decimal places.) (b) Upper P left-parenthesis x greater-than 20 right-parenthesis...

**probability and statistic**

Suppose that the number of asbestos particles in a sample of 1 squared centimeter of dust is a Poisson random variable with a mean of 1000. What is the probability that 10 squared centimeters of dust contains more than 10090 particles? Round your answer to 3 decimal places.

**Calculus**

Yeah That's where I was confused.Probably. Thank you!

**Calculus**

Okay thanks! I have drawn my graph like that!

**Calculus**

Wait the Points are (-1,0) (0,0) and (1,0). Im confused since the critical points and these points are both at x=-1, x=1

**Calculus**

Yes, I was confused why x=-1 and x=1 had two different points. Maybe it's a typo?

**Calculus**

Sketch the graph of the function that has the following properties. f is continuous on (-infinity, infinity). points: (-1,2), (0, 0), (-1,0) f'(x)>0 at (-infinity, -1) f'(-1)=0 f'(x)<0 at (-1, 1) f'(1)=0 f'(x)>0 on (1, infinity) f"(x)<0 on...

**Calculus**

A printed page is to have 1.5 inches margin on all sides. The page should contain 144 square inches of type. What dimension of the page will minimize the area while still meeting these other requirements?

**calc**

Find the volume of the solid generated by revolving the region bounded by y=e^(5/2x),y=0,x=1, and x=5 about the x-axis.

**calc**

Find the volume of the solid generated by revolving the given region in the 1st quadrant about the y-axis: y=10x^2,x=0,y=810.

**calculus**

Find the volume generated by revolving about the x-axis the region bounded by the following curves y=sqrt/(4x+3),x=0,x=4, and y=0. (Use "pi" for π).

**CALC**

Find the volume of the solid obtained by revolving the region bounded by y=(19/3)x-(19/3)x^2 and the x-axis around the x-axis. Keep answer in terms of pi PLease explain each step

**Probability and statistic**

The time until recharge for a battery in a laptop computer under common conditions is normally distributed with mean of 270 minutes and a standard deviation of 50 minutes. a) What is the probability that a battery lasts more than four hours? Entry field with incorrect answer (...

**CALC**

my equation was y=900+C/e^(1/150)t

**CALC**

A 200-gallon tank is currently half full of water that contains 50 pounds of salt. A solution containing 1 pounds of salt per gallon enters the tank at a rate of 6 gallons per minute, and the well-stirred mixture is withdrawn from the tank at a rate of 6 gallons per minute. ...

**Probability and statistics**

Astronomers treat the number of stars in a given volume of space as a Poisson random variable. The density in the Milky Way Galaxy in the vicinity of our solar system is 1 star per 16 cubic light years. (a) What is the probability of 3 or more stars in 16 cubic light years? (b...

**probability and statistic**

Heart failure is due to either natural occurrences (85%) or outside factors (15%). Outside factors are related to induced substances or foreign objects. Natural occurrences are caused by arterial blockage, disease, and infection. Assume that causes of heart failure between ...

**math**

If you will triple the three it is called thrice but when you four what is it

**Chemistry**

Is NH4+ polar or non polar?

**chemistry**

Is NH4+ po;ar or non polar?

**CALC**

the exponent is (y-x^2)

**CALC**

Find the particular solution of the given differential equation dydx=−4xe(y−x^2);y=11whenx=1. THanks

**CALCULUS**

Yes but I'm not sure what the m>0 is for

**CALCULUS**

Let y(t) denote the mass of a radioactive substance at time t.t. Suppose this substance obeys the equation y′(t)=−14y(t). Assume that, initially, the mass of the substance is y(0)=M>0. At what time does half of the mass remain? (Round your answer to 3 decimal ...

**CALC PLEASE HELP**

Suppose that y′=ky, y(0)=7, and y′(0)=4. What is y as a function of t ? PLEASE EXPLAIN

**CALCULUS**

∫4x^−1*sin(ln(6x))dx I got 4*[-cos(ln(6x))]+C but its wrong and im not sure why... Please Help!! Thanks

**CALC**

Find the area of the region bounded by: y=2x−tan0.18x, x=1, x=5, y=0 Round your answer to 3 decimal places. I get 9 but its wrong! please help

**Calculus**

to make it continuous f(2)=a so it would equal -1?

**Calculus**

So a=-1 That makes sense because it's continuous

**Calculus**

find the value of a, if it exists, such that the following function is continuous at X = 2. piecewise function f(x)={x^2-3x+1, if x>2; a, if x=2; 3-2x, if x<2 I found the limits from left and right of 2 = -1 so the limit exists but I don't know how to figure out a

**Math**

Among a group of people, 10% are from NYC and 90% are not. All people from NYC are under 18 years old, and 70% of those not from NYC are also under 18 years old. One person is chosen at random, and he or she is under 18. What is the probability that the person chosen is from ...

**CALCULUS**

Find the derivative of y=4sinx−2cosx

**Business Math**

How long will it take for an investment to double at 7% p.a compounded monthly?

**Calc**

Find the derivative of y=4sinx−2cosx

**Calculus**

let f(x)=2x-7. Use the rigorous definition of limit to show that lim x-->4 f(x)=1

**English**

Can you summarize this case study 300 words minimum? Overview Hospital A: Porter Regional Medical Center (PRMC) Located on the east side of town, Porter Regional Medical Center (PRMC) was a for-profit hospital, consisting of 110 hospital beds, 8 of which were reserved for ...

**geography**

Under the Soviet system, the government a. controlled all forms of communication. b. allowed newspapers to print whatever they wanted. c. controlled editorials but not the reporting of news. d. encouraged access to a wide variety of news sources.

**math**

Find each value if cos A=12/13 with 0 (degrees) <= A <= 90 (degrees) and if sin B=8/17 with 90 (degrees) <= B <=180 (degrees) 1. sin(A+B) 2. cos(A-B) 3. tan(A-B)

**Teachers aide**

What are two types of wheelchairs used by the physically challenged students are the ?I think the two would be a orthosis and the power driven

**Geometry**

31.Identify the Hypothesis of the statement below. If you are riding on a train, then it will stop at every station on the line. A.You are riding on a train B.It will stop at every station on the line C.You are not riding on a train D.It will not stop at every station on the ...

**Math**

15 blocks

**math plz help my last chance to do this homework**

how do you post a pic

**math plz help my last chance to do this homework**

a) write an expression in simplest form for the perimeter of each triangle. b)write another expression in simplest form that shows the difference between the perimeter of the larger triangle and the perimeter of the smaller triangle.

**Algebra**

i think a is right

**Algebra**

Randall wants to mix 41 lb of nuts worth $2 per lb with some nuts worth $8 per lb to make a mixture worth $7 per lb. How many pounds of $8 nuts must he use? Pounds of nuts-cost per pound-total cost 41-$2-? x-$8-? ?-$7-? There is a chart and I...

**Algebra**

A chemist wishes to mix a solution that is 4% acid. She has on hand 66 liters of a 2% acid solution and wishes to add some 8% acid solution to obtain the desired 4% acid solution. How much 8% acid solution should she add? There is a ...

**Algebra**

The height of Tower A is 940 feet more than Tower B. The two towers have a combined height of 1,540 feet. What are the heights of each tower?

**BOB PURSLEY PLEASE HELP**

What is the electrostatic force between one object with a charge of +5.0 × 10−6 C, and a second object with a charge of +2.0 × 10−6 C? The objects are 1.2 meters apart. In a pith ball experiment, the two pith balls are at rest. The magnitude of the ...

**URGENT HELP**

1.In a pith ball experiment, the two pith balls are at rest. The magnitude of the tension in each string is |T| = 0.55 N, and the angle between each string and a vertical line is θ = 27.33°. What are the values for the magnitudes of electrostatic force, Fq, and the ...

**Physics**

@bobpursley

**Physics**

One object has a charge of +5.0 × 10−6 C, and a second object has a charge of +2.0 × 10−6 C. The objects are 0.5 meters apart. What is the electrostatic force between them?

**College Algebra**

Pounds of nuts-cost per pound-total cost 41-$2-? x-$8-? ?-$7-? There is a chart and I have to fill in the question marks. x= 205/6 0r 34.16667

**College Algebra**

Randall wants to mix 41 lb of nuts worth $2 per lb with some nuts worth $8 per lb to make a mixture worth $7 per lb. How many pounds of $8 nuts must he use?

**Chemistry**

Calculate H2 Equation 1- CH4g+2O2g+CO2g+2H2OgH1=-890kj Equation 2- CH4g+O2g+CH2Og+H2OgH2=? Equation 3- CH2Og++O2g+CO2g+H20gH3=-518kj

**Chemistry**

Equation 1- 2Ss+3O2g+2SO3gh1=? Equation 2- 2Ss+2O2g+2SO2gh3=-594kj Equation 3- 2SO2g+O2g+2SO3gh3=-198kj Use Hess's law in your own words.

**Chemistry**

Consider this reaction N2g+O2g+2NOg H=180.5kj How much heat would be required to produce 1.300 mol NOg?

**Chemistry**

The reaction of 1 Mol of iron metal with 3 Mol aqueous HCI produces 1.5 mol H2 gas, 1 mol aqueous FeCI3, and 87.9 kj of heat. Write a thermochemical equation for this reaction

**ELA**

Yeah I get what your saying but I need a to write 2 or 3 paragraph a about what I want to know.. And I want to know the same thing you do but I don't know how to write that in a paragraph explaining!!

**ELA**

What are few questions and stuff that people or anyone would want to know about electrical engineering.... I need help writing 3 paragraphs based on that.

**Chemistry**

Calculate the number of moles of solute in each of the following solutions: Solution Moles of Solute 2.1 L of 0.21 M NH4HCO3 3.5 L of 0.28 M MgCO3

**English p3**

Traditional healers should be allowed to practice and prescribe medicines in hospitals and clinics and i agree with this topic. Speech should be in one page.

**English**

Speech about traditional healers should be allowed to practice and prescribe medicines in hospitals and clinics and I agree with this topic.

**Engineering**

What are few things that people want to know about electrical engineering??

**Journalism**

Anyone.. I am not really sure

**Journalism**

List the things that people actually want to know about electrical engineering

**life orientation**

People should stop engaging in fraud. it is not the only way to make a living. Being engaged in fraud will end you up on jail. You would loose momemts you would have with family

**Journalism**

What site

**Journalism**

I need 15 questions to ask an electrical engineer.

**History essay**

How to write a history essay based on a question with prompts?

**Math**

That's the issue I am having

**Math**

Find all of the solutions for this addition problem. Each different letter in the puzzle stands for a different digit. Letters that are the same stand for the same digit. Remember to include all of the criteria from the guidelines. ONE + ONE = TWO

**math**

seven horses are entered in a race. If two horses are tied for first place, and there are no ties among the other five horses, in how many ways can the seven horses cross the finish line?

**math**

horses are entered in a race. If two horses are tied for first place, and there are no ties among the other five horses, in how many ways can the seven horses cross the finish line?

**Geograph**

I need help writing a paragraph of why the stamp act of 1765 was not fair to the colonist.

**Geography**

Oops wrong one

**Geography**

The Stamp Act of 1765 was the first internal tax levied directly on American colonists by the British government. The act which imposed a tax on all paper documents in the colonies came at a a time when the British empire was deep in debt from the seven years war and looking ...

**george mason**

horses are entered in a race. If two horses are tied for first place, and there are no ties among the other five horses, in how many ways can the seven horses cross the finish line?

**mason**

seven horses are entered in a race. If two horses are tied for first place, and there are no ties among the other five horses, in how many ways can the seven horses cross the finish line?

**Language Arts**

Which of the following passages from the novel best illustrates the most extreme hostility between the Chinese and American communities in San Francisco?

**geography**

How coal is formed?

**precalculus**

solve log(2+x)-log(x-3)=log2 I know the answer is 8

**math**

solve log(2+x)-log(x-3)=log2

**English (research)**

How can I prove that a superhero is a monster? i.e. - Spider-man

**Data analysis**

hello hi did you figure out how to do this? ahahha help

**Math**

Find the rotation in revolutions per minute given the angular speed and the radius given the linear speed and the rate of rotation. 1. w= 2.7 rad/s 2. v=24.8 m/s, 120 rev/min 3. w= 4/3Pi rad/hr Please help me with these problems! I am a visual learner and I learn best when ...

**Math**

2.2 is my answer.

**Math**

Meredith's new scale measures in both pounds and kilograms. The information on the box says the scale has a weight limit of 200 kilograms or 440 pounds. Using this information, approximate the unit rates of kilograms per pound and pounds per kilogram, to the nearest ...

**economics**

yes

**Math/ELA**

What can I do now as a 7th grader to prepare and save for college

**Chem**

Consider the following balanced equation: 2N2H4(g)+N2O4(g)→3N2(g)+4H2O(g) Complete the following table showing the appropriate number of moles of reactants and products. If the number of moles of a reactant is provided, fill in the required amount of the other reactant, ...

**Calculus**

two small planes take off from the same airport at the same time. One travels north at 200 km/h, and the other, west at 150 km/h. If the planes fly at the same altitude, how fast are they separating after 2 hours?

**organic chemistry**

Apart from the fact that between the two structures, only cyclohexe-4-ene-cis-1,2-dicarboxylic acid has the OH group shown on the IR spectrum. In what other majors way will the IR spectrum of cyclohex-4-ene-cis-1,2-dicorboxylic anhydride differ from the IR spectrum of ...

**GEOMETRY HELP PLEASE**

The bases of trapezoid $ABCD$ are $\overline{AB}$ and $\overline{CD}$. We are given that $CD = 8$, $AD = BC = 7$, and $BD = 9$. Find the area of the trapezoid.

**History**

“Without consideration of ‘traditions’ and prejudices, it [Germany] must find the courage to gather our people and their strength for an advance along the road that will lead this people from its present restricted living space to new land and soil, and hence ...

**Precalculs**

solve using matricies x+2y+3z=7 -x+2y-z=1 -x+y-2z=-2 x= y= z= ive tried everyway I can think of please help