Questions Asked on
April 26, 2008

  1. science

    if it takes 31,500 joules of heat to warm 750g of water, what was the temperature change? My answer: Q = (M) (DeltaT) (c) Delta T=Q Delta T = 31,500J -------- 750gx 1.0cal/gCo Delta T = 42oC

    asked by sam
  2. Chemistry

    A solution of I2 was standardized with ascorbic acid. Using a 0.1000-g sample of pure ascorbic acid (C6H8C6), 25.32 ml of I2 were required to reach the starch end point. What is the molarity of the iodine solution? Please check to see if I did this right:

    asked by Ramey
  3. math

    There are 8 singers competing at a talent show. In how many different orders can the singer appear?

    asked by kevin
  4. Biology12

    Can someone please explain: Why are non-coding regions of DNA more discriminating than coding regions? I forgot my textbook at school, and the internet is not providing me with a detailed enough explanation. Thanks.

    asked by Biology
  5. algebra

    a chemist needs 10 liters of a 25% acid solution. the solution is to be mixed from three solutions whose acid concentrations are 10% 20% 50% how may liters of each solution should the chmist use to satisfy the following? a use as little as possible of the

    asked by sandy
  6. physics-repost

    An owl has good night vision because its eyes can detect a light intensity as small as 5.0*10^-13W/M^2. What is the minimum number of photons per second that an owl eye can detect if its pupil has a diameter of 8.5nn and the light has a wavelength of

    asked by Stephy
  7. physics

    Compressed air can be pumped underground into huge caverns as a form of energy storage. The volume of a cavern is 5.60 105 m3, and the pressure of the air in it is 8.40 106 Pa. Assume that air is a diatomic ideal gas whose internal energy U is given by U =

    asked by Karen
  8. 12 Biology

    With regards to RFLPs, why are non-coding regions of DNA more discriminating than coding regions?

    asked by Biology:Repost
  9. macroeconomics

    Why do we consider a business-cycle expansion different from long-run economic growth? Why do we care about the size of the long-run growth rate of real GDP versus the size of the growth rate of the population?

    asked by smeffy
  10. physics

    A mass of 135 g of an element is known to contain 30.1 1023 atoms. What is the element? hydrogen oxyden aluminum carbon Is it aluminum?

    asked by Sophia
  11. ghost in city hall

    Hello all. Does anyone have a scanned copy of "ghost in city hall" worksheet? It is a math worksheet. Thank you, Sandy

    asked by sandy
  12. science

    a car of mass 1360 kg descends from a hill of height 86 m at a constant speed of 20 km/h. assuming that all the potential/kinetic energy of the car goes into heat in the brakes, find the rise in temperature of the brakes (use the heat capacity (C) of the

    asked by kelsee
  13. math

    Hannah had dinner at her favorite restaurant. If the sales rate is 4% and the sales tax on the meal came to $1.25, what was the total cost of the meal, including sales tax and a 20% tip?

    asked by kevin
  14. physics

    A system undergoes a two-step process. In the first step, the internal energy of the system increases by 368 J when 144 J of work is done on the system. In the second step, the internal energy of the system increases by 24 J when 248 J of work is done on

    asked by Will
  15. Chemistry

    Sulfuric acid/ Lead Battery: -the electrodes for the battery are composed of Pb(s), PbO2, and/or PbSO4. What are the half reaction occuring at each electrode? include electrolysis of water: Process Anode/Cathode Initial Charging: Discharging Recharging

    asked by sara
  16. chemistry

    a sample of air has a volume of 140.0 mL a 67 degrees C. at what temperature would its volume be 50.0 mL at constant pressure/

    asked by Gion
  17. Physics

    Background: A monochromatic laser is exciting hydrogen atoms from the n=2 to state to the n=5 state. Question: What is the shortest wavelength observed? -I believe that it will be from n=5 to n=4, but I am not sure what equation to use or how to use the n

    asked by Christina
  18. chem

    What is the pH of a solution prepared by diluting 25.00mL of 0.020M barium hydroxide to a volume of 100.00mL?

    asked by Ginger
  19. physics

    A system does 196 J of work on its environment and gains 40 J of heat in the process. (a) What is the change in the internal energy of the system? J (b) What is the change in the internal energy of the environment? J I thought the answer would be +40 for

    asked by Will
  20. chemistry

    In what ways does the manufacture of a Hybris hybrid powered car use petroleum as a fuel?

    asked by lisa
  21. French

    How do you pronounce "Allons-y", I know the how to pronounce the allons part, but not they y after it.

    asked by Nichole
  22. Physics

    The first and second resonant lengths of an air column that is closed at one end are 15.5 cm and 45.5 cm, respectively. What is the best value for the wavelength?

    asked by Marty

    An owl has good night vision because its eyes can detect a light intensity as small as 5.0*10^-13W/M^2. What is the minimum number of photons per second that an owl eye can detect if its pupil has a diameter of 8.5nn and the light has a wavelength of

    asked by Stephy
  24. Math

    Solve the following equation for A : 2A/3 = 8 + 4A

    asked by Irene
  25. paper on horsemen arena in lexington,KY

    I'm writing a paper on the Lexington horsemen arena in lexington,KY I'm having difficulty with my research. can anyone give any information regarding this football team and its financial trouble.

    asked by Rai
  26. home economics

    Unemployment rate is unacceptably high. Is this positive economics, normative economics, or art of economics and why

    asked by nathan
  27. Algebra II

    1)Find the exact value of sin 165 degrees. Answer: (sqrt6 + sqrt2)/4 2) Simplify: (4m/5n^2)- (n/2m) Answer: (8m^2-5n^3)/10n^2m Thanks

    asked by Lucy
  28. physics

    An apartment has a living room whose dimensions are 2.5 m 4.8 m 5.9 m. Assume that the air in the room is composed of 79% nitrogen (N2) and 21% oxygen (O2). At a temperature of 27°C and a pressure of 1.01 105 Pa, what is the mass (in grams) of the air?

    asked by mike
  29. calc help

    the position function of a particle is given by s=t^3–4t^2–7t t>=0 where s is measured in meters and t in seconds. When does the particle reach a velocity of 10 m/s?

    asked by Adam
  30. Science: heart beats.

    I was wondering if anybody could help me with my science assignment.I was required to write out a method for a controlled experiment testing my hypothesis: "Physical activity affects heart rate" and I've no idea what my method is to test out this

    asked by LiEN
  31. math

    A school has 6th, 7th and 8th period Social Studies classes. One student from each class will be chosen to represent the school in an essay contest. The 6th period finalists are Mike, Sara, Luis and Ed. The 7th period finalists are Ben, Eric, and Sandy.

    asked by kevin
  32. chem

    a flask containing 155cm^3 of hydrogen was collected under a pressure of 22.5 kPa. what pressure would have been required for the volume of gas to have been 90.0 cm^3 assuming the same temperature?

    asked by jerson
  33. chemistry

    Where can I find the reaction that produces ethyl formate, which is Methanol and Methanoic acid?

    asked by Johnathan
  34. chemistry to Dr. Bob

    Balance the equation: Note: If a chemical species coefficient is "1" then "1" needs to be entered in the field before that species. MnO4– + H+ + C2O42– Mn2+ + H2O + CO2 I'm not exactly sure how to do this question..Help?

    asked by rich
  35. Science

    Which of the following is NOT true about the blank for the experiment, 'Analysis of a Complex Iron Salt'? A. A blank is composed of the solvent used to dissolve the analyte. For this experiment, the solvent is a combination of sulfuric acid, phosphoric

    asked by John
  36. Math

    If r = 5 z then 15 z = 3 y, then r = 1. y 2. 2 y 3. 5 y 4. 10 y 5. 15 y

    asked by Irene
  37. Physics

    If the third harmonic of a standing wave in a vibrating string is 600 Hz, what is the fundamental frequency?

    asked by Marty
  38. Math

    Jim is able to sell a hand-carved statue for $670 which was a 35% profit over his cost. How much did the statue originally cost him?

    asked by Irene
  39. English Expression

    Let's find out the differences between Parent's Day in our country and Mother's Day or Father's Day in America. In our country, a memorial day is set by a special date. However, in America, it can be set as an ordinal number day of a special month. For

    asked by John
  40. music

    Hi, I am looking for an old english song, but I don't remember the song title, its a slow love song and the only thing i remember is that the singers are all male and there are more than one, some asian looking probably japanese and also caucasians. The

    asked by nic
  41. physics

    An incident X-ray photon of wavelength 0.2800nm is scattered from an electron that is initially at rest. The photon is scattered at an angle of 180.0 degrees and has a wavelength of 0.2849nm. Use the conservation of linear momentum to find the momentum

    asked by Leah
  42. Physics Help Requested!

    QUESTION What is the change in energy of the hydrogen atom as the electron makes the transition from the n=3 energy level to the n=1 energy level? ANSWER xxx eV

    asked by Chelsea
  43. french/francais

    I need to find out the english for the following french words, I have found the answers but it doesn't make a lot of sense when translated to english. these items are on a list of things to take on a trip. bidon = can (when looking at the list of items can

    asked by helen
  44. Biology

    how are the anthers of a flower adapted to distribute pollen?

    asked by Candice
  45. physics

    In a diesel engine, the piston compresses air at 302 K to a volume that is 0.0628 of the original volume and a pressure that is 48.2 times the original pressure. What is the temperature of the air after the compression? I know pv = nRT, but I don't know

    asked by Karen
  46. calculus

    Let f(x)=–5x(x–5). Then f'(–1)= And after simplifying f'(x)= Hint: You may want to expand and simplify the expression for f(x) first.

    asked by John
  47. Algebra II

    Find the exact solution(s) of the system: (x^2/4)-y^2=1 and x=y^2+1 Answer:(4,sqrt3),(4,-sqrt3) 2)Write an equation for an ellipse if the endpoints of the major axis are at (-8,1) and (8,1) and the endpoints of the minor axis are at (0,-1) and (0,3).

    asked by Lucy
  48. help with SCI

    Are we born with a certain number of fat cells and as we get fatter we get more fat cells or do the fat cells we have just get bigger?

    asked by Dawn
  49. lyman

    find the value of 20x when x= 10

    asked by mary
  50. writing a negative message to a superior

    My issue is that I need a first paragraph buffer before I break the bad news to a superior. Any suggestions?

    asked by Sissy
  51. Weight Record

    Who is the heaviest person in history and what was his/her peak weight? I have heard that the record is held by a woman named Carol Yager, who weighed 1,800 lbs in her prime. What would a person need to do if they wanted to break this record?

    asked by Toby
  52. physics

    An ideal gas at 18.5°C and a pressure of 1.54 105 Pa occupies a volume of 2.10 m3. (a) How many moles of gas are present? moles (b) If the volume is raised to 5.30 m3 and the temperature raised to 31.0°C, what will be the pressure of the gas? Pa

    asked by Sophia
  53. sales tax

    swaetshirts are on sale for 26 dollars and are 15% off. what is the sales price before tax

    asked by kc
  54. Math

    SO how many mins. are in 900 s

    asked by JERRY
  55. Math

    How to find the decimal equivalent of the mixed number and the mixed number is 4 2/5

    asked by PAULA
  56. Chemistry

    You start at sea level on the beach in California. What would the atmospheric pressure be? Then you move to Los Angeles where the altitude is 87 meters above sea level what happens to the boiling point?

    asked by Chrisy
  57. career day

    I would like to be a Gynecologist when I grown up.So,I have to provide all details to describe a Gynecologist.My principal said he need about 10 pages, please I need help. Thank you

    asked by michael
  58. Calculus

    Let f(x)=7x/x–6 Then f'(9)= And after simplifying f'(x)=

    asked by John
  59. international law paper

    can you please revise. thank you Indeed, the Supreme Court of the United States and the lower federal courts have established the set of rules defining the law and practice of the United States. In particular, regarding the exercise of criminal and civil

    asked by Christi
  60. English Expression

    Let's find out how Parents' Day is different from country to country, and let's learn the expressions related to congratulation or praise. O Answering praise O Saying one's own opinion O Answering praise or congratulation How do you express the mind of

    asked by John
  61. year 7 music

    explanation of musical chords and an example. thanks for help.

    asked by ollie
  62. Math

    How to simplify? 11h 179min

    asked by Sami
  63. Math

    SO how many mins. are in 900 s

    asked by James
  64. Math

    Can someone explain this problem to me, I cannot figure out how they came up with the answer. The example in my book does not work with this problem. Find the minor for the element in the 1strow and 2ndcolumn. -3 2 -1 19 13 -18 -19 12 7 correct answer is:

    asked by Sara
  65. Science

    I need to write a paper (1500-2500)on Scientific Inquiry. I need to answer the impact society has had on the progress, if ethical or moral values figure into the research and sharing of information. I have used different search engines, but none have come

    asked by Kally
  66. chemistry

    how does band gap energy work? when dealing with voltages and color change from LEDs[depends on phosphorous percentage]

    asked by sara
  67. chemistry

    Given one of the starting materials and end product for each of the following reactions, show all reactants, reaction conditions in brackets (where known) and products. fluoroethane from ethanol

    asked by Manny
  68. science

    i have to write something about a specific kidney disease. Is acute renal failure specific enough to write about?

    asked by maggie r
  69. Do you know where I could find these vides?

    I am looking for two educational videos: one is entitled "Integrated Curriculum" and the other is a Shoe Store Video... both focus on children in pretend play and children playing an active part of the learning environment.... If you have seen these videos

    asked by MARY
  70. French

    This isnt really homework, but I kinda need to know this... How do you know when to use Est-ce que As-tu or tu as So this is what it says on my sheet thing... 3 different ways to ask questions, plus how to respond to questions 1. Inversion : Tu as un

    asked by Slappy
  71. science

    Write a 700- to 1,050-word paper in APA format that includes the following: o A brief description of the water resource problem in the video and how it originated. o A management and sustainment plan that you think will benefit both sides of the issue. o

    asked by BaBa

    I wanted to know if you can give me examples on connotation, because i looked throughout the internet and im still kind of confused. Thanks

    asked by Soraya
  73. English

    Identifying antecedents 10a. The antecedent in the following sentence is students: Students in online classes have to be organized to keep up with their assignments. 10b. The antecedent in the following sentence is class: Students in online classes have to

    asked by Hilda
  74. Filing/medical information

    I was trying to find information on what differnt numbering filing systems mean such as .... serial unit and unit number etc I can't find any thing thanks of the help

    asked by Aleecia
  75. president bush

    can anyone help me find a quote from president bush and what he says about funding for no child left behind act?

    asked by maggie r
  76. math

    y=4x - 3, work out the value of x when y =11

    asked by beth
  77. Math

    How to find the decimal equivalent of the mixed number and the mixed number is 4 2/5

    asked by Suzie
  78. Calculus

    If f(x)=5x^3–2/x^4 find f'(x) I don't understand what I did wrong for this ((x^4)(4x+7)-(4x^3)(5x^3-2))/(x^4)^2

    asked by John
  79. soial studies

    what are some stories /myths about rhea

    asked by rhea
  80. dr bob science

    In this answer 0.21 cal/g*C. does the degree small zero go over the g or over the C

    asked by sam HELP
  81. science

    what happens to microbes when they are packed in food tins?

    asked by olivia