# Posts by Kelsey

Total # Posts: 604

**College math**

Thank you

**College math**

A circle has center that the origin and radius r. What is r when the circle is tangent e^(-x^2) (but no intersection with e^(-x^2))? explain.... I can graph it and estimate it, but I don't know how to do this by hand.

**Chemistry **

Determine the fluoride ion concentration for a saturated solution of magnesium flouride. (Ksp = 7.4E-11)

**Complex Analysis**

Thank you!

**Complex Analysis**

I need help converting the complex number z = (-1 + sqrt(1 + 4i))/2i to the form rei^(theta). I found what the number in the square root is in the form rei^(theta) is which is sqrt(1 + 4i) = sqrt(17) e^i(tan-1(4) + pi*k) , but I am having trouble dealing with i in the ...

**Math ( lim inf question)**

n is an natural number.

**Math ( lim inf question)**

What is lim inf sin((n*pi)/8) as n --> infinity.

**Math**

How many posts does it take to support a fence around a square field measuring 200ft on a side if posts are placed every 20ft

**Chemistry **

When calcium iodate is added to water at 25 degrees Celsius, the equilibrium concentration of calcium ion was found to be 0.011M. Calculate the value of Ksp for this salt.

**Chemistrt**

I don't have to plug on any numbers I just have to get n2 by itself, but I don't know how to isolate it.

**Chemistrt**

I'm unsure of how to rearrange Balmer's equation to solve for n2. The equation is 1/lambda= R(1/2^2-1/n2^2)

**college algebra**

Three even numbers sum up to 104. The smallest is half the largest and the middle number is 2 3 the largest. What are the three numbers?

**Chemistry **

How many orbitals are available with the following combination of quantum numbers? 1) n = 2; l = 0 2) n = 3; l = 2 3) n = 4; l = 3 I have figured that it is 1) 2s 2) 3d 3) 4f but i don't know what to do after this.

**Math**

Starting from 105 feet away, a person on a bicycle rides towards a checkpoint and then passes it. The rider is traveling at a constant rate of 35 feet per second. The distance between the bicycle and the checkpoint is given by the equation d = 105 - 35t. At what times is the ...

**chemistry**

What would the predicted voltage be if four Zn(s)/ Zn2+(aq) // Ag+(aq) / C (s) cells were connected in series

**Chemistry**

How did the net voltage of the two cells connected in series compare to the net voltage of a single why the calculated cell potentials and the observed cell potentials might be different

**Physics**

A supersonic jet airplane passing directly overhead creates a shock wave that makes an angle of 51? with the horizontal. What is the speed of the airplane? I know that I need to use Sin(x)=c/v but keep getting an incorrect answer.

**Cell Biology**

The concept of receptor affinity does not only apply to the original receptor and ligand. For which of the following pairs of interacting molecules in signal transduction would a change in affinity of one for the other NOT affect how they work in signal transduction? A) ...

**Biology**

The concept of receptor affinity does not only apply to the original receptor and ligand. For which of the following pairs of interacting molecules in signal transduction would a change in affinity of one for the other NOT affect how they work in signal transduction? A) ...

**Physics**

An astronaut with a mass of 90 kg (including spacesuit and equipment) is drifting away from his spaceship at a speed o f.2 m/s with respect to the spaceship. The astronaut is equipped only with a 0.5 kg wrench to help him get back to the ship. With what speed and in what ...

**Algebra**

A 36-meter rope is divided into three pieces. One piece is twice as long as the shortest piece, and the third piece is 1 meter longer than four times the shortest piece. Find the length of the shortest piece.

**Math**

The sum of two numbers is nine. Four times the smaller is equal to two times the larger.

**Chemistry**

I have the answer to this question but the book does not explain WHY this is a good buffer solution? It uses pH=pKa - log(base/acid) and shows 7.2=7.2 - log(1). I don't understand why they can only use pKa7.2 and ignore the pKa 12.7. You are instructed to prepare 100ml of ...

**Chemistry**

So I convert from H+ concentration to moles by just using the molecular weight of a proton? Also, that will eventually give me molarity mol/L but then how do I go from there to pH?

**Chemistry**

I have 25 million gallons of water at a pH of 6.5. I add 17.4 million gallons of 12.5% by wt sodium hypochlorite (NaClO) at a pH of 12.5 to this water. What will my pH of my final solution be? It's been about 5 years since I took chemistry and I just don't remember how...

**Pre Algebra**

Well sorry for any confusion. I took the test and then wrote down all the answers that had (1 pt) next to them, because those are the correct answers. Maybe the test switches the order around for different students? I don't know. Good luck to you all and I apologize for ...

**Pre Algebra**

If you do connexus and are on the unit 6 lesson 7 test: 1) c 2) d 3) b 4) d 5) b 6) a 7) c 8) d 9) c 10) d 11) c 12) b 13) c 14) c 15) d 16) a 17) b 18) c 19) a 20) a 21) c Trust me, these will get you 100% :)

**interest**

Perry has an opportunity to put $12,000 into an investment with an APR of 5.6% compounded annually. How long will it take his investment to double? (round to one decimal place)

**Interest**

Perry has an opportunity to put $12,000 into an investment with an APR of 5.6% compounded annually. Use the number of years you got as an answer in the previous to find out how much Perry’s balance would be at the end of that time. Round to one decimal place.

**probability**

A dog allergy test for people has a 90% accuracy rate. Only 1% of the population has an allergy to dogs (actually it is much smaller than that!). Assume a major pet food manufacturer purchases this test and administers it to 1,000 employees. ~~~~~~~~~~~(Test is +) (-) (Total) ...

**probability**

A dog allergy test for people has a 90% accuracy rate. Only 1% of the population has an allergy to dogs (actually it is much smaller than that!). Assume a major pet food manufacturer purchases this test and administers it to 1,000 employees. (Test is +) (-) (Total) Has Allergy...

**probability**

Betty has several of the standard six-sided dice that are common in many board games. If Betty rolls one of these dice, what is the probability that she rolls a three? use 3 decimal places.

**math**

east to greatest -11 -44 -49 49 -66

**calculus**

Prove that sin(π + θ) = (-sin2θ) / (2cosθ)

**Chemistry**

for each of the following reactions 3.00 moles of each reactant is present initially. Determine the limiting reactant and calculate the moles of product in parentheses that would form Fe2O3 +3H2=2Fe3H2O

**Math**

The time needed to complete a final examination in a particular college course is normally distributed with a mean of 83 minutes and a standard deviation of 13 minutes. Answer the following questions. What is the probability of completing the exam in one hour or less (to 4 ...

**Econ**

Suppose that the U.S. government decides to charge wine consumers a tax. Before the tax, 10 billion bottles of wine were sold every year at a price of $4 per bottle. After the tax, 4 billion bottles of wine are sold every year; consumers pay $7 per bottle (including the tax), ...

**Physics**

Explain how the electric potential energy of a particle can increase when moving from a region of high electric potential to a region of low electric potential energy.

**Physics**

Calculate the total entropy change hat occurs when 2kg of lead at 40 degrees celcius are placed in a very large quantity of water at 10degrees celcius. the specific heat of lead is 0.031 cal/g K).

**Physics**

For chlorine gas, the van der Waals constants are: a = 0.658 J·m3/mol2, and b = 5.62 × 10-5 m3/mol. A 3.0-L tank contains 10.0 moles of chlorine gas at a temperature of 625 K. What is the pressure in the container? A) 15.0 MPa B) 17.3 MPa C) 13.5 MPa D) 18.2 MPa E...

**english**

It is good

**Algebra**

38

**Psychology**

Help me create a mnemonic device to remember the Four Basic Units of Language: Phonemes, Morphemes, Syntax, and Semantics

**Chemistry**

Sulfuric acid can dissolve aluminum metal according to the following reaction. 2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H2(g) Suppose you wanted to dissolve an aluminum block with a mass of 24.4g . What minimum amount of H2SO4 in grams would you need?

**Educational Technology**

Which of the following are Boolean operaters? A.) and, or, not B.) to, for, from C.) a, and, the D.) is, are not

**Algebra**

B.

**chemistry**

At a certain temperature, the equilibrium constant, K, for this reaction is 53.3. H2(g)+I2(g)->2HI(g) At this temperature, the reactants were placed in a container to react. If the partial pressures of H2 and I2 were each 0.300 bar initially, what is the partial pressure of...

**chemistry**

Initially, 0.600 mol of A is present in a 4.00-L solution. 2A[aq]->2B[aq]+C[aq] At equilibrium, 0.200 mol of C is present. Calculate K.

**Chemistry**

Complete combustion of propane (C3H8). How many grams of water are produced when 50 grams of propane are reacted with 101 liters of oxygen @STP? Please explain in deminsionsl analysis and how you type it in the calculator. Thanks c:

**Health**

Regular exercise stimulates ___ which keeps the skeletal system moving to assist digestion and excretion. A.)peristalsis B.)urea C.)digestion D.)villi

**Finance**

After deciding to buy a new car, you can either lease the car or purchase it on a 3-year loan. The car costs $32,000. The lease offer is for $450/month for 36 months, with only $99 due up front. If you buy the car with a 3-year loan, the APR is 7% with monthly compounding. You...

**Finance**

If the APR is 7% with monthly compounding, compute the quarterly rate

**Finance**

You have an investment with 10 semi-annual cash flows of $1000. The first payment is 6 months from today. If the EAR is 11% what is the present value of this investment?

**Finance**

Gene's Art Gallery is notoriously known as a slow-payer. The firm currently needs to borrow $27,500 and only one company will deal with them. The terms of the loan call for daily payments of $100. The first payment is due today. The interest rate is 21.9%, compounded daily...

**Finance**

You just acquired a mortgage in the amount of $249,000 at 6.75% interest, compounded monthly. Equal payments are to be made at the end of each month for 30 years. How much of the first loan payment is interest? (Assume each month is equal to 1/12 of a year)

**Finance**

You are planning to save for retirement over the next 15 years. To do this, you will invest $1,100 a month in a stock account and $500 a month in a bond account. The return on the stock account is expected to be 7%, and the bond account will pay 4%. When you retire, you will ...

**~MATH~**

im form connexus 2 thanks MI and Mr. Bacon

**Science Help!**

Calculate the density of PCl3 gas at 82.5*C and a pressure of 978torr.

**math**

jasmine bought 6 gallons of apple juice. after filling up 4 bottles of the same size with apple juice, she has 0.3 gallons of apple juice left. hhow many gallons of apple juice are in each container?

**Science**

To help me answer this question.

**Science**

describe how the triassic period was a transitional time. during the mesozoic era explain why the boundary between triassic and jurassic period is similar to the boundary between Permian and triassic periods

**Pre Algebra**

When adding the sqare root of 25 and negative 9, which type of number is the sum? Whole Number Irrational Number Integer Radical

**Math**

Arrange the following real numbers in order from greatest to least: 0.8, 0.8(repeating 8), 0.89(repeating 89), 0.889( repeating the second 8 and 9), and 0.88. I think I got it, but just want to make sure.

**Chemistry**

Solubility Rules!! Homework problem I desperately need help with Solutions used: 6M HCl, 6M NaOH, 6M NH3, 3M H2SO4 Mixed with: Cr(NO3)3, Fe(NO3)3, Bi(NO3)3, Mg(NO3)2, Pb(NO3)2 please help me and tell me which form precipitates and which

**Math Help..!**

A stock's price dropped from $63.28 per share to $27.45. What was the loss on a single share of the stock?

**Math, Please Help!**

Find the a/b form, where a and b are integers and b isn't equal to 0, for each of the following: A. 0.29 (29 repeating) B. 0.00029 (29 repeating)

**Math**

Identify the sequence as arithmetic. geometric, or neither.. explain your answer 1.6, 0.8, 0.4, 0.2....

**HELP MATH !!**

thanks

**HELP MATH !!**

can you show how you got the answer ?

**HELP MATH !!**

Melanie charges $4.50 per hour when she washes cars, plus $5.00 for supplies. Which function rule represents the amount y Melanie charges to wash cars for x hours? (1 point) a) y = 0.50x b) y = 4.50x + 5.00 c) y = 5.00x + 4.50 d) y = 9.50x The sale price of apples at a local ...

**math**

1. Mandy kept track of the trade-in value of a collector’s coin for several months through February of this year. She determined the line of best fit for the data was y = 4x + 12, where y is the trade-in value, in dollars, x months after February of this year. According ...

**math**

6. Kevin wants to calculate the value of the expression below. Which shows an equivalent way Kevin could write this expression? - 17 + 3 a) - (17 + 3) b) - (17 - 3) c) (- 3 + 17) d) ( - 3 - 17)

**MATH HELP PLEASE!!**

1. Mandy kept track of the trade-in value of a collector’s coin for several months through February of this year. She determined the line of best fit for the data was y = 4x + 12, where y is the trade-in value, in dollars, x months after February of this year. According ...

**math**

1. Cynthia used some of the ordered pairs from the set below to make a new set. {(4, –3), (–2, 5), (5, 4), (7, 2), (2, –7)} She wrote the domain of this set as {2, 4, 5}. Which ordered pairs from the original set did Cynthia use to make her new set? a)(–2, ...

**math**

1. Gina wrote this system of linear equations: 2x + y = 7 4x + 5y = 11 Which of the following shows the first four steps that Gina could have used to correctly solve this system for x? a) y = 7 – 2x 4x + 5(7 – 2x) = 11 4x + 25 – 10x = 11 25 – 6x = 11 b) y...

**SCIENCE HELP !!**

Choose one destination that is represented by a flag. Write a paragraph about the effects of climate change in that destination.

**SCIENCE HELP !!**

Suppose humans significantly increased their harvest of catfish, causing a decline in the catfish population. Predict what effect this would most likely have on the population of muskrats. Explain your reasoning.

**SCIENCE HELP !!**

Decades from now, people will still want to harvest food from the world’s oceans. Describe one action people can take now that will improve ocean fishing in the future.

**SCIENCE HELP !!**

1. Iron can form ions with different charges. Explain how this is possible. 2. Ions are often formed when two different elements interact with each other. Explain why this happens.

**science help !!**

1. Why is California’s high-speed rail such a groundbreaking effort? 2. Why will it take so long to complete the high-speed rail route?

**language help !**

1. c 2. d 3. c

**language help !**

Albert Einstein, a world-famous mathematician was born in Bavaria in 1879. He acquired Swiss nationality in 1901 and he began working at the Swiss patent office the next year. Einstein was however also publishing papers in physics. He became famous for his theories of ...

**language help !**

1.a 2.b 3.d

**language help !**

On February 12 1908 a difficult automobile race was in progress. Six cars left New York for Paris in a route that included the United States, Japan, Russia, Poland, Germany and part of France Met by blizzards and other dangers the racers nevertheless kept on. The German entry ...

**language help !**

1. B 2. A 3. C

**language help !**

In all of recent American history, there has been no worse river flooding than what occurred on the Mississippi River between late June and the middle of August in 1993. Record flooding affected communities from Minnesota to Missouri. Iowa and Illinois joined those states as ...

**language help !**

1. a 2. d 4. c

**language help !**

my answers 1. b 2. a 3. d 4. b

**language help !**

DAD: Where’s the water now? MOM: As high as the car’s wheels. DAD: We’d better go. MOM: We can’t. The car’s dead. DAD: What? MOM: The water is up to the engine; it won’t start. TINA: Oh, no! MARK: What can we do? DAD: I don’t know. (He looks ...

**math help !**

1. b 2. a

**math help !**

1. A rectangular prism has a width of 92 ft and a volume of 240 ft3. Find the volume of a similar prism with a width of 23 ft. Round to the nearest tenth, if necessary. a)3.8 ft3 b)60 ft3 c)15 ft3 d)10.4 ft3 2.A pyramid has a height of 5 in. and a surface area of 90 in2. Find ...

**HELP PLEASE !!**

1. b 2. a 3. d 4. b

**HELP PLEASE !!**

DAD: Where’s the water now? MOM: As high as the car’s wheels. DAD: We’d better go. MOM: We can’t. The car’s dead. DAD: What? MOM: The water is up to the engine; it won’t start. TINA: Oh, no! MARK: What can we do? DAD: I don’t know. (He looks ...

**science help**

Every individual, including young people, can make decisions to use resources wisely. Use the terms reduce, reuse, and recycle to explain how the students in the image can help minimize solid waste.

**HELP I DON'T UNDERSTAND THIS QUESTION !**

Earth's energy sources include both renewable and nonrenewable resources. Name at least three sources of energy that could be used in your house.Then describe the ideal energy source for generating most of your home's electricity and explain why you chose that source.

**math help !**

3. Which function rule would help you find the values in the table ? n 2 4 6 m -8 -16 -24 A) m = -2n B) m = n - 2 C) m = n - 4 D) m = -4n 2. Explain how to write a function rule from the table below. Then write a function rule. x 2 4 6 y 1 0 –1

**math**

Explain how to write a function rule from the table below. Then write a function rule. x 2 4 6 y 1 0 –1

**math**

the function rule C = 10n + 26 relates the number of people n who attend a small concert to the cost in dollars C of the concert. Make a table of the input/output pairs to show the cost if 27, 39, and 43 people attend.

**science help**

a slab of limestone that contains 3 fossils