Wednesday

July 8, 2015

July 8, 2015

Total # Posts: 731

**Math**

The scores of students on standardized test are normally distributed with a mean of 300 and a standard deviation of 40. Between what two values do 99.7% of the test scores lie?
*March 1, 2014*

**math- commutative property**

The Answer Is D Because if you have 4 pencils and i have 7 apples, how many pancakes will fit on the roof? well the answer is purple because aliens don't wear hats. Thanks :)
*January 9, 2014*

**chemistry**

a 350ml buffer solution is .150M in HF and .150M in NAF. What mass of naoh could this buffer neutralize before ph rises above 4.0? So far I got .285714 from 10^-.544. After that I tried to do .285714(x/.0525-x) but this doesn't worl. The answer is 1.2g. Help, please?
*January 4, 2014*

**English **

does anyone know of a website where i can get info on why vampires attract the interest of human beings? thank you its for a essay
*December 10, 2013*

**English**

go to easy bib
*December 1, 2013*

**math**

On a map of the Fox River, 1 centimeter represents 6.5 kilometers. If a trail by the river is actually 26.65 kilometers long, what is the length of the river on the map?
*November 19, 2013*

**Math **

Solve for x: 4(2-x)>8x+20
*October 17, 2013*

**chemistry**

What is the final volume in milliliters when 0.700L of a 46.9% (m/v) solution is diluted to 20.1% (m/v)?
*October 16, 2013*

**Chemistry-**

Okay, i thought so...I was confused since I'm using N with the units in a formula but I can't seem to find a way to cancel it out. Maybe you would know how? Formula: Z= Zwall x Area 4.18x10^14 mol s^-1 / 6.04x10^23 m^-2 s^-1 = Area 8.4x10^-6 m mol = r How would I ...
*October 1, 2013*

**Chemistry- **

If I was trying to find out the number of molecules(N) using moles x avogadro's number, what units would N have?
*October 1, 2013*

**Chemistry**

A tubular fluorescent lamp in a fully evacuated supply compartment on the international space station was originally filled with a small amount of mercury vapour. When the lamp began to flicker the astronauts complained there was a tiny hole in the tube. They measured that the...
*October 1, 2013*

**Maths**

An initial-value problem is given by the differential equation, f(x,y) = –20xy2, y(1) = 1. Use the classical fourth-order Runge-Kutta method with a step-size of h = 0.02, to obtain the approximate value of y(1.02). Give your answer to 6 decimal places.
*September 29, 2013*

**Average deviation**

If I'm asked for the average deviation, what is the unit I should use for the answer?
*September 28, 2013*

**Chemistry**

An 8.07g sample of impure Ag2O decomposes into solid silver and O2(g). If 395mL O2 is collected over water at 25C and 749.2mmHg barometric pressure, then what is the percent by mass of AgO2 in the sample? The vapor pressure of water at 25C is 23.8mmHg. Could someone help me ...
*September 27, 2013*

**Chemistry**

2 NaN3(s) = 2 Na(l) + 3 N2(g) How many grams of NaN3 are needed to produce 20L of N2(g) at 303K and 776mmHg?
*September 24, 2013*

**Chemistry**

The half life of U238 is 4.5 x 10^9 yr. A sample of rock of 1.6 g produces 29 dis/sec. Assuming all radioactivity is due to U238 find percent by mass of U 238. I have tried ln(t)/ln(0)= -kt and still cannot get the answer What I get is A) 4.5x10^9 x365x60x60x24=1.419x10^17 for...
*September 22, 2013*

**Business math**

A store had 896 swimsuits that were marked to sell at $46.99. Each suit was marked down $15.90. Find the reduced price using the formula M = S – N, where M is the markdown, S is the original selling price, and N is the reduced price.
*September 8, 2013*

**Chemistry re-post**

I took a look at this question to see if I copied it correctly, and it does NOT say how much of the solution was used. It does use mols as the unit. Dr. Bob, I am not sure what you mean by "decays into Argon." I realize that the 38 CL decays to Argon, but how would ...
*July 23, 2013*

**Chemistry **

I posted this before and am sorry to post again and take up room but it is due this week and I'd like to understand how to get the answer (no one has responded yet): question The nuclide 38cl decays by beta emission with a half life of 40min. A sample of .40 m of H38cl is ...
*July 22, 2013*

**Chemistry**

I posted this before a few hours ago without a reply yet but decided I would add more detail: question The nuclide 38cl decays by beta emission with a half life of 40min. A sample of .40 m of H38cl is placed in a 6.24 liter container. After 80 min the pressure is 1650 mmHg. ...
*July 21, 2013*

**Chemistry **

The nuclide 38cl decays by beta emission with a half life of 40min. A sample of .40 m of H38cl is placed in a 6.24 liter container. After 80 min the pressure is 1650 mmHg. What is temperature of container? I have tried calculating the decay rate of the 38cl and then plugging ...
*July 21, 2013*

**chemistry**

write a balanced equation for the chain reaction AL2O3
*July 13, 2013*

**Statistics**

is that 2C = 0.0229885?
*May 18, 2013*

**mathematic**

OK but really about part C I'm confused. I think it should be 25% or 0.25 but it is wrong!!!!
*May 18, 2013*

**math **

solve by the elimination method x + y = -2 4x - 6y = -3
*May 9, 2013*

**Calculus**

In a right triangle, if one leg (adjacent to 90 degrees) is 10cm, which is increasing at the speed of 2cm/s; and another leg is 24 cm, which is decreasing at 2cm/s. how fast is the hypotenuse changing at this time?
*May 6, 2013*

**Trig**

A plane has a speed of 250mph and flies with a bearing of N35degE. The wind is blowing from the west at 25 mph with a heading of due east. What is the actual speed and heading of the plane? Round to one decimal place.
*April 21, 2013*

**chemistry**

A gas with a volume of 4.20 L at a pressure of 0.63 atm is allowed to expand until the volume raises to 95 L. What is the new pressure (in atm)?
*April 19, 2013*

**chemistry**

A gas with a volume of 4.20 L at a pressure of 0.63 atm is allowed to expand until the volume raises to 95 L. What is the new pressure (in atm)?
*April 19, 2013*

**math**

Put this in exponent form: (3square root of x) ( square root of x cubed)
*April 18, 2013*

**Math**

Ill just use log then I think I get tht... but how did u come to 2^x=112...?
*April 18, 2013*

**Math**

Mr.Reiny, We don't use logs yet, so how do I find it without using log?
*April 18, 2013*

**Math**

Solve for x 2^x+1 - 2^x = 112 Put this in exponent form: (3square root of x) ( square root of 3 cubed) Put into equation form: Horizontal stretch of 2, up 3, left 6, reflection on x-axis. Please help me with these three so I can work on the rest using these as examples. Thanks...
*April 18, 2013*

**gr 11 Math**

Solve for x 2^x+1 - 2^x = 112 Put this in exponent form: (3square root of x) ( square root of 3 cubed) Put into equation form: Horizontal stretch of 2, up 3, left 6, reflection on x-axis. Please help me with these three so I can work on the rest using these as examples. Thanks...
*April 18, 2013*

**math**

(3square root of x) ( square root of 3 cubed)
*April 18, 2013*

**math**

Solve for x 2^x+1 - 2^x = 112 Put this in exponent form: (3¡îx)(¡îx©ø) Put into equation form: Horizontal stretch of 2, up 3, left 6, reflection on x-axis. Please help me with these three so I can work on the rest using these as examples. ...
*April 18, 2013*

**english**

Religion is non-existent and present simultaneously in the form of preconditioning and technology, social classes are used for defining individual purpose and harmony among citizens, and drug use is the backbone for provoking happiness. Would that be a good sentence?
*April 16, 2013*

**english**

yeah but how doi make this sentence into a better sentence for the endof my into like the three main points I will be discussing. How do I end my intro?? We r not allowed to us first person.
*April 16, 2013*

**english**

There is total social stability, there is almost no disease, very low crime, high rates of happiness and acceptance of death.
*April 16, 2013*

**english**

science and technology
*April 16, 2013*

**english**

so Ms.Sue, can you help me with my last sentence of intro about what three arguments. I am going to talk about in my body paragraphs.
*April 16, 2013*

**English..Ms.Sue(take a look here please)**

hmm.. well I don't know I cant think of any more...at the end how do I put it into a level 4 sentence including what I will be writing about in the body:(
*April 16, 2013*

**English..Ms.Sue(take a look here please)**

It can be a utopia since each individual is happy..right? But that is only one can u help me wid the other 2? and putting it all in a sentence... Ms.Sue!!! This is worth 15% it is a summative:( My life stinks...I need ur guidance..
*April 16, 2013*

**English..Ms.Sue(take a look here please)**

yes I understand that, I checked the sites out and they say first step is to pick up a topic, which in this case is what I don't understand, then ask a question regarding the topic than answer the question and finally reword the answer. So can u plzzzz help me with the ...
*April 16, 2013*

**English..Ms.Sue(take a look here please)**

Discuss the society in Brave New World as a utopia. What should i make my thesis be??? Please help im so lost. It is a utopia •English - Ms. Sue, Tuesday, April 16, 2013 at 1:14pm I think a good thesis would be: Brave New World reflects a dystopia, not a utopia. •...
*April 16, 2013*

**English**

But it says.. discuss the society in Brave new world as a utopia. So don't you think the thesis should be more detailed and well structured.
*April 16, 2013*

**English**

Discuss the society in Brave New World as a utopia. What should i make my thesis be??? Please help im so lost. It is a utopia
*April 16, 2013*

**English**

Its a utopia as i saiid above
*April 15, 2013*

**English**

I have already visited those sites... I have read the book and it is a utopia. I just want a excellent thesis:( but i just cant think of one. Please help me if u can.
*April 15, 2013*

**English**

Discuss the society in Brave New World as a utopia. What should i make my thesis be??? Please help im so lost.
*April 15, 2013*

**algebra**

In the early months of some year, one site added 0.6 million new accounts every day. at this rate, how many days would be needed to add 30 million new accounts?
*April 14, 2013*

**chemistry**

The escape velocity from earth is 2.5 x10^4 miles per hour. What is this speed in m/s? (1 mile 1609 m)
*April 14, 2013*

**math**

Simplify this expression by using the properties of exponents.You may leave your answer as a number to a power. (2c)^5(2c^9)^6=
*April 13, 2013*

**finance**

You have a fairly large portfolio of U.S. stocks and bonds. You meet a financial planner at a social gathering who suggests that you diversify your portfolio by investing in emerging market stocks. Discuss whether the correlation results in Exhibit 3.10 support this suggestion
*April 11, 2013*

**Pre-Algebra**

Find 3 consecutive positive integers such that the product of the first and third, minus the second, is 1 more than 5 times the third.
*April 7, 2013*

**Psychology**

One way to measure the validity of test would be to:
*April 5, 2013*

**Psychology**

The weather person on the evening news reports that the average daily rainfall for the last six months is 10 inches. A farmer is trying to determine how the rain might affect his crops.
*April 5, 2013*

**Psychology**

My answer is A.
*April 5, 2013*

**Psychology**

Professor Webb is interested in conducting a study on gender differences and coping with stress. He should begin his research by examining:
*April 5, 2013*

**algebra**

Thank you so much
*March 31, 2013*

**algebra**

y= -x^2-12x+28 A painter can use the formula A=2/3bh to estimate the area of space under the parabola. Calculate area in square ft under each arch ~ if there are 8 arches to be painted how many square ft must be painted ~ if 1 gallon paints 200 square ft , how many gallons ...
*March 31, 2013*

**Math**

Jimmy jumped into a lake from a 12-foot-high cliff with an initial upward velocity of 7 feet per second. Find the time in seconds it took Jimmy to enter the water. Use the model for vertical motion given by the equation h = -16 t squared + vt + s
*March 28, 2013*

**Chemistry**

this is the equetion for question 2 CaO+2NH4Cl-2NH3+H2O+CaCl2
*March 20, 2013*

**Chemistry**

1. The reaction CO+2H2-CH3OH was carried and it is found that only 332g of CH3Oh is actually produced when 407g CH3Oh was the expected yield. What is the Percent yield? 2. If 112g of CaO is reactied with an excess of NH4Cl and 64.0g of NH3 are produced, what is the percent ...
*March 20, 2013*

**curriculum development**

The size of a play/work area in the class made a noticeable difference in the time children stayed there and were engaged in complex play. The best size area is A) small and open B) large and open c) small and sheltered or d) large and sheltered. is B) large and open correct?
*March 19, 2013*

**Exceptional children**

i appreciate ure help! can u check this last one for me The final goal of a functional approach to managing prblem behavior is to a.) change the child b.) replace an inappropriate behavior with a good one. c.) change the environmet or d.) help child understand how to behave. i...
*March 19, 2013*

**Exceptional children**

Can you check my answers please Adaptive behaviors are a.) the same as fuctional skills b.) different from functional skills c.) exclude functional skills or d.) include functional skills. this is tricky for me but i'm guessing d.) include funtional skills. Does this sound...
*March 19, 2013*

**geometry**

If the measure of ÐDAB = 50°, and ÐDAC = 20°, what is ÐCAB?
*March 13, 2013*

**Chemistry**

If you have 1.90 mol of H_2 , how many grams of NH_3 can be produced?
*March 5, 2013*

**Chemistry**

If you have 1.90 mol of H_2 , how many grams of NH_3 can be produced?
*March 5, 2013*

**Physics**

Ok so F=MA thanks, I do appreciate especially since I am going to 35th reunion and went back to school. Much harder than I remembered. Again thanks
*March 5, 2013*

**Physics**

Sorry just re-learning after 30+ years.I had part of it answered however, the 4th and 5th question info was pertaining to questions 3 and 4 so I had to ask the question from the beginning. My answer was T = 1.585 s. for speed I calc 0.942/1.585s=0.594...right? my real problem ...
*March 5, 2013*

**Physics**

A 0.500 kg particle moves in a circle of R=0.0150 m at constant speed. The time for 20 complete revolutions is 31.7 s. What is the period T of the motion? What is the speed of the particle? What is the centripetal acceleration of the particle? What is the centripetal force on ...
*March 5, 2013*

**chemistry**

the equilibrium constant of the decomposition of NOCL is 1.6*10^-5. calculatethe concentration of all species at equilibrium if initially 3.52 mol of NOCL is placed in a 5.00 L container
*March 4, 2013*

**Chemistry**

The triprotic acid H3A has ionization constants of Ka1 = 6.8× 10–3, Ka2 = 8.1× 10–9, and Ka3 = 5.0× 10–12. Calculate the following values for a 0.0760 M solution of NaH2A [H+] = ? [H2A-]/[H3A]= ? Calculate the following values for a 0.0760 M ...
*February 26, 2013*

**Chemistry**

Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.100 M phosphoric acid solution. pKa1 = 2.16 pKa2 = 7.21 pKa3 = 12.32 [H3PO4] = ? [H2PO4-] = ? [HPO42...
*February 26, 2013*

**Chemistry**

What fraction of piperazine (perhydro-1,4-diazine) is in each of its three forms (H2A, HA–, A2–) at pH 7.22?
*February 26, 2013*

**Chemistry**

A certain indicator, HA, has a Ka value of 1.3 × 10-6. The protonated form of the indicator is blue and the ionized form is red. What is the pKa of the indicator? What is the color of this indicator in a solution with pH = 8? Blue, red, or purple?
*February 26, 2013*

**Chemistry**

This question has been bugging me for a long time. A rock contains a Pb-206 to U-238 mass ratio of .145 to 1.00. Assuming that it did not contain any Pb-206 at the beginning of its formation, determine its age. I assume from the other problems in my book that the 1/2 life is 4...
*February 23, 2013*

**chemistry**

However, when I try to find the rate constant I get 3.5. My book says 3.5^-.5. I don't know how they got this. .0069= (.010)^.5(.020)=approx 3.5 but the book says 3.5M^-1/2*s-1 Also I am wondering if there are three reactants in a problem, is there any difference how it is...
*February 23, 2013*

**chemistry**

I have a problem like this: CHCl3 + Cl2 = CCl4 +HCL This is the rate table: CHCL3 Cl2 Initial Rate .010 .010 .0035 .020 .010 .0069 .020 .020 .0098 .040 .040 .027 They want me to find the rate constant and the rate law.
*February 23, 2013*

**Math**

At a summer camp, one boy and one girl will be selected to lead the weekly activities. If there are 130 boys and 145 girls at the camp, how many different 2 person combinations of 1 boy and 1 girl are possible?
*February 5, 2013*

**Math**

On friday, a computer was priced at $800. on the following wednesday, the price was reduced by 15%. On the following friday, the price was further reduced by 20%. what percent of the original price was the final price ?
*February 5, 2013*

**Chemistry**

180
*January 29, 2013*

**english**

The reason your voice matters is because its part of the way you want to be respected, spoken to, as well as you are part of a family of individuals. The fact that you have ideas of your own and you have values and an opinion is also why your voice should be heard. You have ...
*January 8, 2013*

**geometry**

LPG is stored in highly insulated spherical vessels in most oil refineriesif.If the inside diameter of one of these tanks is 11.4ft, find it's volume. Report your answer to the nearest one-tenth of a gal. Use r=3.14 and 1 cubic ft=7.5gal
*December 29, 2012*

**geometry**

find the volume of an industrial tank in the form of a horizontal cylinder whose radius is 2.6 yd, and whose length is 8.4 yd. rr=3.14
*December 29, 2012*

**chemistry**

When compound A is heated with acid compound B forms. Ahas the formula C3H8O and B is C3H6. When Ais oxidized compound D forms that is further oxidized to carboxylic acid. What are compounds A, B, and C.
*December 17, 2012*

**chemistry**

What is the pH of a solution prepared by dissolving 1.533 g HCl in water to make 420 mL of solution
*December 17, 2012*

**biology**

Following the usual pathway of circulation blood flows from the __________ to ___________, to_____________and to__________
*December 14, 2012*

**biology**

The ___________ ____________ supplies blood from the heart to all organs except the lungs
*December 14, 2012*

**biology**

Terms like punctiform and round relate to colonial ____________while smooth and curled relate to colonial___________
*December 14, 2012*

**biology**

Traditional phylogenetic results have been challenged by the results of _________________
*December 14, 2012*

**pre-algebra**

the perimeter of a pool is 150m. the width is 1/2 its length. what are the dimensions of the pool
*December 13, 2012*

**Chemisrty**

A 10.0 g sample of ice at -14.0°C is mixed with 124.0 g of water at 81.0°C. Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The heat capacities of H2O(s) and H2O(l) are 2.08 and 4.18 J/g°C, respectively, and the enthalpy of...
*December 9, 2012*

**Accounting**

Harris company borrowed 65,000 by giving 10 year , 6% installment note to Cuba Bank The note requires annual payments of $8832 first payment occuring on the last day of the fiscal year. the first payment consists of interest of $3,900 and principal repayment of $4932, Issued ...
*December 6, 2012*

**Psychology**

the spillover effect is best explained in terms of the?
*November 17, 2012*

**nuclear chemistry**

wouldn't you divide by the speed of light squared? nuclear chemistry - andrew, Saturday, November 10, 2012 at 8:26pm E=mc^2 10^6 J/s are being produced (1Mw) 10^6 J/s = m (3.0e8 m/s) solve for mass to find amount of mass lost in one second. ~ .0033kg
*November 10, 2012*

**nuclear chemistry**

A typical nuclear reactor produces 1mw of power per day. What is the minimum rate of mass loss required to produce this energy. Don't know where to start
*November 10, 2012*