Sunday
February 14, 2016

Total # Posts: 377

chemistry
what are some examples of suspensions?
June 1, 2011

Chemistry
Will you check this answer for me? the half-life of strontium-87 is 2.8hr. What percentage of this isotope will remain after 8 hours and 24 minutes? ?? 34%
May 25, 2011

Pre-Calc
A hall 200 feet in length is to be designed as an ellipse if the foci are 35 feet from the center. How high will the ceiling be from the center?
May 11, 2011

Pre-Calc
A mirror is in the shape of a paraboloid. If a light source is 6 feet from the base along the axis of symmetry and the opening is 12 feet across, how deep should the mirror be?
May 11, 2011

math
Colin is working to earn some money for a new cd player. On Saturday he earned half as much as he did on Sunday, but twice as much as he did on Friday. During those three days he earned \$70. How much did he earn each day?
April 11, 2011

probability
I was asked to find the probaility if a board game uses the deck of 20 cards. And find how many have the number 3. I came up with 4/20 and was told that I'm on the right track but I need to find P(3 and 3) with replacement and without replacement. What does this mean?
February 14, 2011

Probability
How do I determine the probability of selecting a card greater than 9 or a black card?
February 8, 2011

probability
The odds against Paul Phillips winning the 100 yard dash are 7:2. Determine the probability that: • a) Paul wins. • b) Paul does not win. How do I set this up to find out the equation/answer?
February 1, 2011

chemistry
4. Use the pressure of the butane gas (your answer from question #3 above), along with the temperature and volume recorded in the lab, to determine the moles of butane gas collected in the lab. You will use the ideal gas law (and the ideal gas constant, R) for this calculation...
February 1, 2011

Math
Would the set up be [(p-->q)^~p]-->~q
January 21, 2011

Math
If you pass general chemistry, then you can take organic chemistry. You pass general chemistry. ˆ You can take organic chemistry. Let P = you pass general chemistry Let Q = you can take organic chemistry I came up with P - >Q P therefore Q But my set up is wrong...
January 21, 2011

precalc
f(x)=Log1/3^(9x)find the domain and range.
January 14, 2011

chemistry
consider the following reaction: 2C2H6(g)+7O2 (g)-->4CO2(g)+6H2O (g) delta H = -3120kJ If 3.00g of ethane are burned, how many kJ of heat are produced?
January 13, 2011

chemistry
consider the following reaction: C3H8 (g)+ 5O2 (g)--> 3CO2 (g)+ 4H20 (g) Delta H = -2440kJ The heat of formation of CO2 is -390 kJ/mol and the heat of formation of H2O is -240 kJ/mol. What is the heat of formation of propane?
January 13, 2011

chemistry
the following reaction is carried out in a bomb calorimeter: 4NH3 (g) +5O2 (g)-->4NO (g)+6H2O (g) The calorimeter constant is 45.0kJ/K. when 34.0g of NH3 are reacted in the calorimeter, the temp rises by 10 degrees C. What is the change in energy, delta E, for the rxn?"
January 13, 2011

Math
Time's 5
January 13, 2011

Spanish
when you are talking in past tense. for example: you went swimming yesterday.
January 9, 2011

Chemistry-Help!!
If I have 10mL of 1.0 M Ba(OH)2 solution and add it to 2.5L of water. What is the concentration of hydroxide ions in the diluted Ba(OH)2 solution?
December 7, 2010

Chemistry-Confused!!
You have 10mL of a 1.0 M Ba(OH)2 solution and add it to 2.5L of water. What is the concentration of hydroxide ions in the diluted Ba(OH)2 solution?
December 7, 2010

MATH HELP!!
what is the unit rate for 67.92 for 4gal
December 6, 2010

Chemistry-urgent!
Yes, but would that give me 63 mL or 250 mL. That's where I get confused.
November 30, 2010

Chemistry-urgent!
What volume of 2.5% (w/v) KOH can be prepared from 125 mL of a 5.0% KOH solution?
November 30, 2010

An aqueous mixture containing starch (a colloid), NaCl, glucose, and albumin (a colloid) is placed in a dialyzing bag and immersed in distilled water. Which of the following correctly describes the location of the indicated substance after dialysis? A-albumin, inside B-starch ...
November 30, 2010

Chemistry
I'm having trouble with molarity. What is the molarity of a KCl solution made by diluting 75.0 mL of a 0.200 M solution to a final volume of 100.0 mL?
November 29, 2010

Math
Find the present value of the annuity necessary to fund the withdrawal of \$600 per month for 10 years, if the annuity earns 2% per year and if there is to be \$10,000 to be left in the annuity at the end of the 10 years. (Assume end-of-period withdrawal and compounding at the ...
November 18, 2010

Math
Find the present value of the annuity necessary to fund the withdrawal of \$600 per month for 10 years, if the annuity earns 2% per year and if there is to be \$10,000 to be left in the annuity at the end of the 10 years. (Assume end-of-period withdrawal and compounding at the ...
November 18, 2010

socail studies
new england colonies 2. what? what happend to the coloonists at roanoke? whta happend to the colony at sagadaco? 5. where? where was roanke? where was sagadahoc? where was james feild?
October 28, 2010

social studies
What was the name of William Lloyd Garrison's anti-slavery newspaper.
October 27, 2010

math
what is the perimater of a 90 degree angle multiply by 2 a 17 multiply that answer by 7 add 90 and subtract 23.
October 27, 2010

writing
My teacher said,write 10 sentences 5 for each Paragraph..she said here is your topic. If you would write a speech what would you write it about. Now im not writing a speech im writing i i would write a speech what would i write it on im havinc alot of trouble help please....???
October 26, 2010

math
if you used 2 hundreds, 18 tens, and 4 ones to model a number. what number did you model?
October 21, 2010

Chemistry
A 112 mL solution of 0.351 M HCl is added to 52.0 mL of 0.161 M HCl. What is the new concentration of HCl?
October 21, 2010

Chemistry
what is the concentration of Cl- after adding 250 mL of 0.10 M AlCl3 to 250 mL of 0.30 M Ca(NO3)2
October 21, 2010

I need a website that will tell me everything about The Independence Debate:Consequences for the Colonies?
October 19, 2010

English
How do you fix this pronoun agreement. The first theme that the author demonstrates is to not let people with a disability feel abnormal, but for them to use the abilities that they have to help them build their self-confidence.
September 28, 2010

Quick ?
I doing a sample lesson plan for my english class. I want to show a movie that realtes to the book that were reading and the movie is 106 minutes. I teach each class for 50 minutes a day. How many days would it take to finish the movie and how long is 106 minutes?
September 27, 2010

Art
Why is important for children to draw pictures of things that scare them (otherwise what does the child learn from this?
September 26, 2010

math
If you had a fraction strip folded into tenths what fractional lengths could yu measure with the strip?
September 23, 2010

math
The tread life of a particular tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 2000 miles. What is the probability that a randomly selected tire of this brand will last longer than 58,000 miles? A.0.7266...
September 18, 2010

alegebra
i don't know any i need help asap!
September 14, 2010

science
A ball is dropped from a cliff and has an acceleration of 9.8 m/s2. How long will it take the ball to reach a speed of 24.5 m/s?
September 7, 2010

Math
Mike can mow a lawn in 3 hours. Paul can mow the same lawn in 2 hours. How long would it take both of them working together to mow the lawn? The answer is suppose to be 20/9. This is what I did and I get 9/20. What am i doing wrong? 1.4x+1/5x=1 which gives u 9/20. I'm so ...
August 31, 2010

Math
Solve each inequality algebraically. |2x-1|-2<3 I don't understand how the answer is -2<x<3
August 30, 2010

Math
A student scored 65, 80, 74 on the first three tests during the term. What does the student need to score on the fourth test to ensure and an average score that is above 75?
August 27, 2010

math
How do I start off this equation? Using correct mathematical notation and symbols, express the following in set builder notation: Z = {4, 5, 6, 7, 8, 9, 10, 11}
August 18, 2010

math
Given these sets: A = {1, 2, 3, 4} B = {3, 4, 5, 6, 7} C = {3, 5, 7, 9} List the elements of this set C ¿ (A u B) Do I list the numbers in C that is not in A and B?
August 15, 2010

math
Sealing a Gym Floor A gymnasium floor has an area of 2400 square yards. Each gallon of floor sealant covers an area of 350 square feet. How many gallons of sealant are needed to cover the gymnasium floor? should the equation be set as 2400 sq. yards = 7200 sq. feet 7200 sq ft...
August 11, 2010

college mathematics
how do I set up an equation for this? Lisa has \$215 saved. She plans to save \$125 every month so that she can have enough money to buy a new sofa. The sofa costs \$1498, including tax. How many months will she need to save to be able to buy the sofa?
August 11, 2010

college mathematics
1-1=0 0-2=-2 -2-3=-5 -5-4=-9 -9-5=-14 (would it be this)
August 11, 2010

college mathematics
Use inductive reasoning to predict the next three numbers in the sequence. 1, 0, -2, -5, -9,
August 11, 2010

algebra
Use inductive reasoning to predict the next complete line in the pattern. 10 × 12 = 11 × 13 - 23 12 × 14 = 13 × 15 - 27 14 × 16 = 15 × 17 - 31
August 9, 2010

algebra1
The sears tower in Chicago is 1,454 feet high. suppose you take a sheet of paper and fold it once in half, than fold it in half again,and keep folding it over and over again. How many times would you have to fold it to create a piece of paper that is higher than the sears tower?
May 6, 2010

social studies
What three countries border Egypt?
April 13, 2010

Math
in a subdivison, 67% of the homes have detatched garages, 32% have a patio & 13% have both. What is the probability that a house has a patio if u know that it has a detached garage?
March 25, 2010

physics
im trying to find the speed of a tyrannosaurus rex by alexanders froude number. sp= (square root of)leg length x gravity/ froude number sp=(square root of) 3.5 x 9.8 / 11 i get 1.76 but a t rex cant run/ walk at 1.76 m/s or km/h nothing fits
February 26, 2010

Math
Ya it says How many ounces of each solution should be mixed to prepare the desired perscription? Why is there a 50 in parentheses next to the .54? So once I solve for x what do I do next?
February 26, 2010

Math
A pharmacist is to prepare a 50 fluid ounce solution that contains 54% glucose. The pharmacy has a 30% solution and a 90% solution on hand. How many ounces of each solution should be mixed to prepare the desired perscription?
February 26, 2010

Math
x/2-3=x/5+1 The answer is suppose to be 40/3... I don't know how do this
February 3, 2010

English
why is it important to know the story elements when reading a text and writing a narrative
February 1, 2010

English
How do text and word help me understand the meaning of words while I read and write?
February 1, 2010

Math
How do you solve this equation? The answer is suppose to be -0.7 Thanx for you help. Greatly appreciated -5x\9=7/18
January 29, 2010

Science
yes it is B
January 26, 2010

linear system problems
the base of an isosceles triangle is one third the lenght of each congruent sides the perimeter of the triangle is 84 cm how long is the base?
January 18, 2010

French help part 2
I have a few more if anyone could review them I would be so grateful!!!!! 11.Quand il finira ce cours, il ___D ira____ au Japon. A. va B. est allé C. irait D. ira E. allait 12.Hier, à 9 heures du soir, elle __A a fini______ son devoir. A. a fini B. finit C. ...
January 12, 2010

French help
Thank you E.G. and Kanon!!!
January 12, 2010

French help
Are these answers correct? Thank you!! 1. Elle voit ses amis au cinéma. Elle ___la___ voit 2. Nous parlons souvent à nos professeurs tous les jours. Nous __les____ parlons tous les jours. 3.Martine va en Chine, Elle _le_____ va pour étudier la culture ...
January 12, 2010

geometry
if 4, 6, and 10 and 14, 21, and x are the lengths of the corresponding sides of two similar triangles, what is the value of x?
January 10, 2010

math
greatest common factor of 12 numbers less than 40 list each pair
January 5, 2010

French question
Nous ________ cours vers 9 heures a. voulons b. faisons c. allons d. Commençons I can't decide between B and D. Thank you!
December 11, 2009

Thank you!!!
December 11, 2009

I need help with these two French 101 questions please. Thank you!! Je connais bien Mireille. Je _________ connais depuis 30 ans a. le b. la c. y.....I think this is correct d. lui Marie est une nouvelle étudiante. Hélène lui parle. Choisissez la forme ...
December 11, 2009

Social Studies
What are the four main natural resources in the united states? and what does silt do to help farmland?
December 7, 2009

English
Can you please just check the grammar in this for me. Thank you Nella Larsen theme is to teach the readers that sometimes it is best to deny ones racial heritage rather than to accept it or identify with it. When it comes to certain situations when race is an issue, the ending...
November 30, 2009

English
What do you mean by one life lesson is strongly related to others?
November 26, 2009

English
Why do some authors have more than one theme to their novel? What is the significance of that?
November 26, 2009

Chemistry 101
Thank you Dr Bob!!!!
November 24, 2009

Chemistry 101
Are these correct? 1. A sample of gases contains three gases at the following pressures: 1.2 atm N2, 3.2 atm O2, and 0.56 atm Xe. What is the total pressure in the container? a. 5.0atm b. 1.4atm c. 2.2atm d. 1.0atm e. 1.7atm I am pretty sure it is A. Is that correct? 2. The ...
November 24, 2009

English
what are the importance of taboos and why are they used in modern literature. Are taboos considered a characterisc of modernism
November 24, 2009

English
Why are taboos used by authors in their writing?
November 24, 2009

French help
Thank you very much Samantha and Kanon!!!
November 24, 2009

French help
Hi. There is a word missing in this sentence. Would it be pour? Thank you! Le week-end, j’aime aller à la plage ______ faire bronzer et nager mais seulement quand il fait chaud.
November 24, 2009

English
Can you please tell me what this means?I don't understand it at all. Thank you for your help. I hate this type of literature. Modernism is that if everything is based on perception, then history is false; therefore the society emerges from that history is also false. The ...
November 24, 2009

French help part 2
Thank you for the help. I don't understand the question for #1 either.
November 19, 2009

French help part 2
Hi. I am trying for an A in my French class and every point counts. I would appreciate any feedback on my answers. Thank you!! Complétez les phrases suivantes avec une forme d’un de ces verbes: croire, voir, recevoir. 1. Jean et Julien __________ Jean et Julien- I...
November 19, 2009

French help part 1
Hello!!!! I am so close to an A in French. I would be so grateful if someone could review this and tell me if I am correct. Thank you!!!!! Complétez chaque phrase avec la forme appropriée d’un de ces verbes. Dire, lire, écrire. 1. Elle n’aime pas...
November 19, 2009

French 101 help Part 2
Hi. I would really appreciate it is someone could review my answers for these questions.I am horrible with accents and always lose points. Are those correct as well? Thank you in advance!!! Complétez avec la forme correcte de savoir ou connaitre 6) __________ -vous qu&#...
November 16, 2009

French 101 help
Hi. Would someone please review and tell me if these are correct? Thank you!!!! Remplacez le nom dans les citations avec un pronom d'objet direct ou indirect selon des cas. 1) Est-ce que vous “me” regardez? Oui, nous . . . A:Oui, nous te regardons. 2) Les mauvais...
November 16, 2009

it wants me to add an independent or dependent clause........they chose which clause to use, ex. when the student artist showed his work to the teacher......I'm to add an independant clause......I don't know what they're asking.....
November 11, 2009

French 101
Is vécu correct? Voici Christophe. Il ________ (vivre) à Paris pendant deux ans. Thank you!!
November 9, 2009

French help
I have to fill in the blanks of this sentence with 5 of the 8 words provided but I am totally lost. I would appreciate any help. ___(1)___ soir, nous ___(2)___ rencontré des amis au restaurant. Nous ___(3)___ avons ___(4)___ le jour précédent. Après...
November 5, 2009

Then...Does your experimental empirical formula (answer to #5) agree with the known empirical formula (answer to #6) of zinc chloride? List and describe some sources of error that may have affected your results The only factor of error I can think of is that the ions weren'...
October 26, 2009

The next question is Determine the actual empirical formula of zinc chloride, based on the ionic charges of zinc and chloride ions, using your rules for ionic nomenclature. Because Zn has +2 ions and Cl has -1 the actual empirical formula is ZnCl2
October 26, 2009

Thank you for your reply. The Zn in grams 1.80= .028 moles Zn and Cl in grams 0.90= .025 moles Cl The question was: What is the EXPERIMENTAL empirical formula of zinc chloride? Determine the simplest whole number ratio of moles of zinc used, to moles of chlorine reacted in the...
October 26, 2009

Chemistry
Is this correct? What is the experimental empirical formula of zinc chloride? Determine the simplest whole number ratio of moles of zinc used, to moles of chlorine reacted in the zinc chloride that was produced..028 moles of Zinc .025 moles of Cl .025 moles of Cl is smaller ....
October 26, 2009

external and internal character traits
is external and internal traits about the person?
October 18, 2009

French
trente trente-cinq quarante
October 13, 2009