Sunday

October 23, 2016
Total # Posts: 1,050

**Chem**

Ca(s) + 2H+(aq) → Ca2+(aq) + H2(g) An experiment is performed to determine the volume of hydrogen gas produced when calcium reacts with excess HCl(aq) as represented by the net ionic equation above. A 0.0720 g sample of pure calcium and a solution of 1.0 M HCl(aq) were ...

*April 23, 2013*

**AP Chem**

CH3CH2NH2(aq) + H2O(l) <-> CH3CH2NH3+(aq) + OH-(aq) Kb = 5.0e-4 Ethylamine, CH3CH2NH, a weak base reacts with water according to the equation above. A 50.0 mL sample of a ethylamine solution is found to have a pH of the solution 11.60. (a) Write the expression for the ...

*April 23, 2013*

**Science**

Explain why would a bottle that is left overnight with water is crack but a empty bottle would not.

*April 14, 2013*

**Scoence**

Explain why would a bottle that is left overnight with water is crack but a empty bottle would not.

*April 14, 2013*

**Combinations and Permutations, Steve and Ms. Sue☺**

thx guys u helped me out alot and yes slim is right

*April 10, 2013*

**Macroeconomics**

GDP of a country is 6000 billion. Investment is 2100 billion. Government purchase is 300 billion. The country has a trade surplus of 200 billion. How much is consumption? Was there net capital inflow or outflow? Can someone help start me off for this?

*April 10, 2013*

**chemistry 1 help please!**

Write a chemical equation that shows how acid rain H2SO3 was produced from SO2 gas and water in a zip sealed bag? My chem. teacher never explained how to do this and I have several other questions on this type of subject. If you could help me out it would help me tremendously...

*April 9, 2013*

**Chem 1**

Write a chemical equation that shows how acid rain H2SO3 was produced from SO2 gas and water in a zip sealed bag? My chem. teacher never explained how to do this and I have several other questions on this type of subject. If you could help me out it would help me tremendously...

*April 9, 2013*

**Macroeconomics**

The money supply in Freedonia is $200 billion. Nominal GDP is $800 billion and real GDP is $400 billion. Assuming that velocity is stable, if real GDP grows by 10 percent this year, and if the money supply does not change this year, what is the change of price level?

*April 9, 2013*

**Algebra **

I have one question I really need help with. I know the partial sum process but my numbers don't seem to come out to what I think it should be. Find the partial sum S6 1. An=3n+2

*April 4, 2013*

**Algebra please**

I have two left I need help with and don't understand. Find the partial sum S6 1. An=3n+2 2. Find the number of terms n in an arithmetic sequence if a1=20, d=5, and An=75.

*April 3, 2013*

**Algebra**

Thanks for the help bobpursley and Reiny I appreciate showing how you got to it so I can also do it.

*April 3, 2013*

**Algebra **

I have 3 questions I'm stuck on and would love for someone to explain and show me how to solve them so I can also solve the other one. Find the partial sum S6 1. An=3n+2 2. Find the number of terms n in an arithmetic sequence if a1=20, d=5, and An=75. 3. Find the general ...

*April 3, 2013*

**Algebra **

I have a few problems I need some help with. The first is Evaluate the sum. 1. There is an E like symbol on the top is 10 on the bottom n=1 and to the right (7-2n) 2. The next question is find a10 for an arithmetic sequence with a1=6 and d=10 3. Find the number of terms in the...

*April 3, 2013*

**Math**

A theater group made appearances in two cities. The hotel charge before tax in the second city was $1000 higher than in the first. The tax in the first city was 4% , and the tax in the second city was 7% . The total hotel tax paid for the two cities was $455 . How much was the...

*April 1, 2013*

**Calculus**

Calculate the area of the common interior of r = 2sin(theta) and r = 2cos(theta)

*March 27, 2013*

**physics**

A person weights 685 N in air but only 497 N when standing in water up to the hips. Find (a) the volume of each of the person’s legs and (b) the mass of each leg, assuming they have a density that is 1.05 times the density of water.

*March 25, 2013*

**Business**

I have to write a research paper on MBWA (Management by walking around) but I honestly can't think of any good thesis's, or topics to write about. Any ideas?

*March 25, 2013*

**AP Calc Help!!**

Let f be the function satisfying f'(x)=x√(f(x)) for all real numbers x, where f(3)=25. 1. Find f''(3). 2. Write an expression for y=f(x) by solving the differential equation dy/dx=x√y with the initial condition f(3)=25. Please show work and reasoning.

*March 21, 2013*

**Math **

Simplify: 5th roof of (6th root of 10 * sqaure root of 1000) or: (10^1/6 * 1000^1/2)^1/5 (^ another way of writing it)

*March 20, 2013*

**physics**

You're in an auto traveling at 25.0m/s toward a pole mounted warning siren. If the siren's frequency is 365 Hz, what frequency do you hear? Use 343m/s as the speed of sound.

*March 20, 2013*

**Math**

7.24 multiplied by 3.4. Find the solution and round to the tenths. I'm confused I have two answers

*March 17, 2013*

**Quantum M.**

Why "In Hilbert Space noone can hear you scream"?

*March 10, 2013*

**math**

16.7%

*March 6, 2013*

**math**

this was emily's full day yesterday: she spent 8 hours sleeping, 1 hour in the shower, 6 hours in class, 2 hours eating and snacking, 4 hours studying, and 3 hiurs watching tv. What percent of her day was spent studying.

*March 6, 2013*

**math**

Answer is 40%

*March 6, 2013*

**math**

a movie theater has 250 seats. One hundred tickets have been sold. What percent of fhe theater is filled?

*March 6, 2013*

**maths**

A particle of mass 4 kg is attached to one end of an inelastic string and a particle of mass 2 kg is attached to the other end of the string.The string has length 4m and is hung over a smooth pivot at its midpoint. The Pivot lies 3m above the ground.How long does it take for ...

*March 2, 2013*

**Calculus AP**

Added spaces for it to let me add the picture. h t t p : / / g o o . g l / v S l t p

*March 1, 2013*

**Calculus AP**

Let R be the region bounded by the graphs of y=cos((pi x)/2) and y=x^2-(26/5)x+1. A. Find the area of R. B. The vertical line x=k splits the region R into two equal parts. Write, but do not solve, an equation involving integrals that solves for k. C. The region R is the base ...

*March 1, 2013*

**Calculus AP**

I spaced it out. This the picture. h t t p : / / g o o. g l / A h g J X

*March 1, 2013*

**Calculus AP**

Let R be the region in the first quadrant bounded by the graph y=3-√x the horizontal line y=1, and the y-axis as shown in the figure to the right. Please show all work. 1. Find the area of R 2. Write but do not evaluate, an integral expression that gives the volume of ...

*March 1, 2013*

**Math**

Oh I get it now, okay thank you very much!!

*February 24, 2013*

**Math**

Dalia made 8 party bags for her birthday party. Each bag contained 4 small gifts for her friends. When Denis said that she could come, Dalia had to make one more bag with 4 gifts. How many small gifts did Dalia need to fill her bags? Walter wrote this number model: 8 x (4+4)=...

*February 24, 2013*

**maths**

1) Suppose that an insect crawls in a plane in a path given in polar coordinates by r = be^kt; theta = kt; where b; k are positive constants and t is time.Find the velocity and acceleration vectors of the insect. Show that the angle between the velocity and acceleration ...

*February 20, 2013*

**Math**

How do you solve g? 4 = (1 + g)^20

*February 15, 2013*

**Macroeconomics**

Suppose GDP is $800 billion, taxes are $150 billion, private saving is $50 billion and public saving is $20 billion. Assuming this economy is closed, calculate consumption, government purchases, national saving and investment.

*February 14, 2013*

**math**

Suppose that you deposit $1735.50 in a savings account that pays 9.25% annual interest with interest credited to the account at the end of each year. Assuming no withdrawals are made, find the balance in the account after 4 years

*February 12, 2013*

**Math**

What are the steps to solve for n?: 50000 = 1000(1 + 0.8)^n

*February 11, 2013*

**maths**

1)is the ring of real polynomials R[X] countable and why ?

*February 10, 2013*

**maths**

Let a, b, c and d be vectors. (i) Show that (a - b) * (a + b) = a^2 - b^2

*February 6, 2013*

**Physic **

A block (mass 2.4 kg) is hanging from a massless cord that is wrapped around a pulley -3 2 (moment of inertia of the pulley = 1.3 x 10 kg·m ), as the drawing shows. Initially the pulley is prevented from rotating and the block is stationary. Then, the pulley is allowed ...

*February 4, 2013*

**English**

Thank you so much!

*February 1, 2013*

**English**

Rephrase the main idea of the sample in your own words, without repeating words or sentence structure from the original statement. (I honestly can't seem to decide on how it should be worded) "Air pollution can also have a significant impact on our economy. It can ...

*February 1, 2013*

**English**

I have: NPD have pointed out that smartphones have rapidly increased 84 percent from 2007 to 2008, and are currently selling fast in America.

*February 1, 2013*

**English**

Rephrase the main idea of the sample in your own words, without repeating words or sentence structure from the original statement. "Right now, smartphones are selling like mad in the U.S. market, where sales jumped 84 percent between 2007 and 2008, according to NPD, the ...

*February 1, 2013*

**East**

I need an equation that has something to do with the role of static friction in the design of tires

*January 31, 2013*

**maths**

n! is greater or equal to 2^n-1 prove by induction

*January 11, 2013*

**math**

A tree is struck by lightning. The top part breaks and falls to the ground. The part of the tree still standing is 30 feet tall and the top part that hit the ground is 40 feet from the base of the tree. How tall was the tree originally?

*January 10, 2013*

**maths**

integrate by parts integrate (4+x^2)^1/2

*December 29, 2012*

**ap calculus**

I'm sorry... I'm just not super comfortable posting my name on the web... Can you still please help me??

*December 19, 2012*

**ap calculus**

Which of the following definite integrals gives the length of y = e^(e^x) between x=0 and x=1? All the answers are preceded by the integral sign from 0 to 1. (a) sqrt[1 + e^(2*(x+e^x))] dx (b) sqrt[1 + e^(4x)] dx (c) sqrt[1 + e^(x+e^x)] dx (d) sqrt[1 + e^(2e^x)] dx (e) sqrt[e...

*December 19, 2012*

**chemistry**

Sorry but what do Ka/Kb values tell me?

*December 15, 2012*

**chemistry**

I know caffeine is more polar than salicylic acid but how would I explain that given their respective structures? I know for smaller molecules you would figure out the polarity of individual bonds and the molecule's geometry but I can't figure out how to transfer this...

*December 15, 2012*

**Math**

He's allowed to keep it is the fish is exactly 22 inches so you need to find the difference between 22 and the actual length of the fish (i.e. subtract how long the fish is from 22)

*December 15, 2012*

**chemistry**

Please help. My teacher never went over crystal lattices and the book doesn't cover it either :( Copper crystallizes in a face-centered cubic lattice. If the edge of the unit cell is 351pm, what is the radius of the copper atom?

*December 10, 2012*

**Social Studies **

In what ways did China And Europe parallel each other in their development until the sixth century CE? How did they diverge after that?

*December 8, 2012*

**math**

in order to increase the mean of 6 numbers by 3, what would the total sum of the increase be? A. 3 B.9 C.12 D.16 E.18

*December 7, 2012*

**MATH urgent**

Hello!! 1. find the third derivative of f(t)=(t-1)/(t+1) 2. y= x^(x^2) ; dy/dx please help! thank you!

*December 6, 2012*

**HEALTH HELP PLEASE!!**

Fats help maintain your cell membranes. (1 point) True False 12. Your body does not use energy when you sleep. (1 point) True False 13. People with anorexia nervosa eat large amounts of food and then purge. (1 point) True False 14. Your body image is the way others see your ...

*December 5, 2012*

**maths**

Let p(x) = 1 + 4x + 2x^2 + 2x^3 in Z5[x]. Find all roots of p(x), and write p(x) as a product of irreducible polynomials.

*December 5, 2012*

**maths**

differentaite w.r to x h(x) = arcosh(x^3 + 2).

*November 25, 2012*

**pre cal**

How lnog will it take for an investment of $1000 to double in value if it earns 5% coumpounded weekly?

*November 24, 2012*

**Maths**

in the following rings find all units, Zero divisors and idompotent elements and determine whether the ring is a field. a)Z2 b)Z5 c)Z10 NB z is integers( positive or negatives including zero z is integers( positive or negatives including zero

*November 20, 2012*

**physics**

An object moves along a circular path with a constant speed, |⃗vo|. (Semi Circle with point A on one side point B on the other. Looks like a 90 degree angle with points A and B on either side of the hypotenuse.) The average acceleration in going from A to B is 1. zero 2...

*November 8, 2012*

**Maths**

steve

*November 8, 2012*

**Maths**

(cos8x+cos2x)/2 steve is it right

*November 8, 2012*

**Maths**

cos3xcos5x how do rewrie this using trigmetric finctions Steve thanks

*November 8, 2012*

**Maths**

Steve help please

*November 8, 2012*

**Maths**

how did you do sin2x cos4x = (sin6x + sin2x)/2 what os the formula I need to use

*November 8, 2012*

**Maths**

1)how do you simplify 3xcos5x using trigometric functions 2)how do you simplify sin2xcos4x using trigometric functions

*November 8, 2012*

**maths**

thanks steve SO DOES ANSWER CHANGE IF ABELIAN?

*November 6, 2012*

**maths**

let G be a group with operation . and let p,q be two elements of G. simplify p.q.q.q^-1.p^-1.q^-1 as much as possible.does answer change if G is ABELIAN?

*November 6, 2012*

**MATHS**

prove by mathematical induction that 7^n+4^n+1 is divisible by 6

*October 31, 2012*

**Geometry**

my geometry problem set says "find the ratio of CG : CB" CG=6.3 and CB=19 so to find the ratio i would divide the 19 by 6.3 (we have to round so it would be a 3:1 ratio) or would it be the other way around? i think it's the 19/6.3 but i'm not sure...

*October 25, 2012*

**math **

I am a 3 digits number less than 200. the tenths place is 2x more than the ones place. the number in the ones place is 2. what number am i?

*October 24, 2012*

**orgoo**

calculate how to make 10 mL of 15:85 ethyl acetate:hexane solution from 2 mL of 5:95 ethyl acetate:hexane, using pure hexane and pure ethyl acetate.

*October 13, 2012*

**writing**

I have to write an essay about how Morrison uses power stuggle in Beloved to enhance the meaning of her work. I think I have some idea, but I'm just sitting here numberless. This essay is due in about 2 days. Can you help me ASAP? Thanks

*October 12, 2012*

**Physics**

1. mg/(cos(sin^-1(r/L)))

*October 10, 2012*

**world civilization**

what was the relationship between politics and science in the early modern world?

*October 4, 2012*

**Chemistry**

A particular oral contraceptive contains 0.041 mg of ethinyl estradiol in each pill. The formula of this compound is C20H24O2. How many moles of ethinyl estradiol are there in one pill? I need help in approaching this

*October 3, 2012*

**math**

Is 4,564,282 a prime or composite number?! Seriously, I have absolutely no idea!!!!!!

*September 26, 2012*

**Chemistry H.**

5.07301149

*September 23, 2012*

**orgoo**

what are the products of the reaction: HC3OH + (Na+NH2-) ?

*September 14, 2012*

**orgo**

What is the pH of a 5.00E-2 M solution of acetylsalicylic acid, pKa = 3.52.

*September 14, 2012*

**chem**

calculate the pH of 5x10^-2 M of benzoic acid with pKa= 4.19

*September 14, 2012*

**math**

what is the rule for the following: x = 1,2,3 y = 2,6,12

*September 12, 2012*

**Physics**

A bug completes one lap along the edge of a circular planter of radius 22.4 cm in 16.45 s. How fast was it traveling? Answer in units of cm/s.

*September 9, 2012*

**aglebra 2**

determine whether the equation has one solution, no solution, or is an identity. 5y+3=26

*September 6, 2012*

**chem**

P1V1/T1=P2V2/T2 ; basic proportion. STP mean standard temperature and pressure P1=700 torr V1=8 Liters T1=293K P2=standard pressure=1 atm=760 torr V2=unknown T2=standard temperature=273K i hope you can follow my though process. (700*8)/293=(760*V)/273 V=6.87

*August 13, 2012*

**microeconomics**

a. $7, 125 units b. $8, 100 c. Producers and customer pay equal amounts.

*July 28, 2012*

**Dressmaking and design**

a straight facing can be used to finish?

*July 24, 2012*

**Bio HELP!!!!**

what is the name of the process throughh which polypeptides, polysaccharides or triglycerides are catabolised (broken down)?

*July 7, 2012*

**math**

Use the midpoint formula

*July 7, 2012*

**chemistry**

.5566

*June 21, 2012*

**math equations**

Solve x = log3 15

*June 12, 2012*

**Chemistry**

how much chlorine, Cl 2, do you need to order to react completely with 500 kg of platinum, Pt, to make cisplatin, PtCl 2(NH 3) 2?

*June 5, 2012*

**Algebra 2**

five chips numbered 1 through 5 are placed in a bag. A chip is drawn and replaced. Then a second chip is drawn. Find the probability that the first chip is even and the other one is odd.

*May 30, 2012*

**Chemistry**

Exothermic means you release energy. D, freezing water, means the water releases heat in order to freeze. This release of heat, aka energy, makes it exothermic. The other answer choices require energy, making them endothermic.

*May 22, 2012*

**World History**

China had the largest economy still, thankfully I got it right. Thanks though!

*May 22, 2012*