Posts by bobpursley

Total # Posts: 46,807

  1. History

    Nope, not at all.
  2. Physics

    work added up the ramp: force*distance=50*2=100joules work extraced by gravity= 9(9.8*2*sin19) final KE=initial KE+workdone-PEgained=1/2 * 9(9.8)2^2+100-9*(9.8)2*sin19 from final KE, solve for final velocity.
  3. science

  4. science

    boiling is a physical change, electrolisis is a chemical change. This is occuring below the boiling point, so it is probably chemical change.
  5. Series RL circuits

    Z=97+j110 in magnitude, Z=sqrt(97^2+110^2)=147ohms
  6. physics

    No graph. But is should show MA=5 is ideal.
  7. physics

    probably the first.
  8. Math

    no, yes
  9. Chemistry

    I am wondering why you don't just quote the original source for this plagiarized material?
  10. science

    you get the same number of moles of MgO as you started with moles of Mg. So how many moles of Mg is 24 grams?
  11. Math-please check

    yes, on 22. On number two, An+1=2*An. so each term is twice the previous term.
  12. physics

    find the time it takes to fall 1.1 m find the horizonal distnace it goes in that time
  13. Physics

    find the time it takes to have a final height of zero altitude. with that time, how far horizontally does it travel?
  14. physics

    newlength=2m+(2*5e-4)(20)-2(6e-4)(40)=1.97m check my work
  15. Pabarabuk Secondary School ( Subject Chemistry)

    PV=nRT n=PV/RT but n= mass/molmass so mass=molmasso2*P*V/RT
  16. Science

    The traveled 2km East, then 1km West. Net displacment is 1kmEast
  17. Science

    1km East.
  18. Chem

    210e-6 molar of what? Phosophate ion? seems to me if it 210e^-6 M, and you dilute it 25 times , then it is diluted 25 times. or new concentration is 210e-6/25=8.40 * 10^-6 M
  19. Science

    depends. liquid Carbon dioxide, under pressure and at -50C, is the most dense of all those substances. At normal temps, and pressures, milkshake is most dense.
  20. Physics

    Not now, we are working on a more flexible input field. Or a white board.
  21. Physics

    No emails. Our web safety issues don't allow that.
  22. Physics

    review section 5.2 of this:
  23. Math

    I don't know what you did with trying to format with spaces, but it didn't work.
  24. chem

    get the listed partial pressure of water vapor at your temperature, for a chart. Pressurebutant=totalpressue-PartialPressureH2O
  25. Math I need HELP please

    Surface Area= 2*bottom+side =2*PI*r^2 + PI*2r*h
  26. Maths

    I think you mean this: Data... 3,4,5,5,6,7,7,8 Mode ?? In a set of data, the mode is the most frequently observed data value. There may be no mode if no value appears more than any other. There may also be two modes (bimodal), three modes (trimodal), or four or more modes (...
  27. Science

    wondering exactly what this has to do with a scientific hypothesis? Do you have a hypothesis? Look that word up.
  28. Civics Economics

    3. Nixon emphasized the strong economy and his success in foreign affairs, while McGovern ran on a platform calling for an immediate end to the Vietnam War, in the 1972 election. 4. Some argued that such actions must be authorized by Congress under the War Powers Resolution, ...
  29. Civics Economics

    2. you need to do some reading. 4 again, read 5. Folks argue, and argue, but I think you are wrong.
  30. English (essay question)

    on the first: consider "rhyme" means "similar" or "parallel" on the second, you are on track, but often it is work. Everyone wants a salary, but fewer want the work. for classic, consider ballet, opera, symphonies... or even Jazz. We often want to...
  31. Biology

    Hmmm. Ok, then consider rapidly changing domesticated species, for food. A bird that has no feathers, large meat breast, short legs, eats plant wastes.
  32. Biology

    start with the body segments, legs, antenna, tounge.
  33. Biology

    I would eliminate the "poison" part. It wouldn't survive if it ate poison. What about something like eat a wide variety of green plants and nectar bearing flowers, have 13 body segments, six legs, two antenna, and a tounge that can extend twice as far as the ...
  34. Chemistry

    what is 5*(273-12)/(273+25) ?
  35. Chem

  36. Physics

    stay the same. What ever angular momentum the bug gains, the disk loses. Newtons third law.
  37. AP Physics

    9e9*1.6e-19*1.6e-19/5.3e-11=you are correct
  38. chemistry

    What is 4 times? 4x273=???? PV=nrT
  39. chemistry

    see other post
  40. English

    I agree both.
  41. Math

    thanks. Is there a question here?
  42. technology

    it is a test where you can look in books, the internet, and several other places to find the answers.
  43. Maths

  44. science

    Temporary hardness is caused by dissolved calcium hydrogencarbonate (which is removed by boiling). Permanent hardness is caused by dissolved calcium sulfate (which is not removed by boiling). Water can be softened using washing soda or an ion-exchange resin. The so-called ...
  45. physics

    Find the electric potential at both points. v1=kq1/x=k(2.4e-3)/.150 v2=kq1/(sqrt(.250^2+.250^2) now the work is (v2-V1)(-4.3e-3), where q1 is 2.40e-3 C, and k is 9.0 x 109
  46. Chemistry

    Both aldehydes and ketones are polar molecules because of the presence of the carbon-oxygen double bond. ... Although the aldehydes and ketones are highly polar molecules, they don't have any hydrogen atoms attached directly to the oxygen, and so they can't hydrogen ...
  47. Chemistry

    reasonable, hydrogen bonding.
  48. Social Studies Study Guide

    1,3 are wrong.
  49. Calculus

    dP/dt=.04*P(1-p/500) Is this it? It seems like an odd function for rat population.
  50. Math urgent

    what does x stand for? My crystal ball is not working today.
  51. maths literacy

    Ok, I did that, thanks. Do you have a question, or do you intend to guess my number?
  52. Science

    a. what is PI*radius? b. distance is 15km. Displacement is zero.
  53. 5th grade Math

    A is the correct choice. Most often, we use weight as an indication of mass, but there are other ways, such as in the inertial balance.
  54. MATH!!! URGENT!!!!

    expected times= Pr*n = .6*5=3 =.6*10=6 =.6*30=18 =.6*160=...
  55. Maths Algebra Application Practice

  56. Probability

  57. Math

    b is the best answer. Thirdly, the folks returning from the civil war had few homes to go to (carpetbaggers took their land), so becoming a cowboy was a way out.
  58. Chemistry

    first calcluate the price per mole Example: A. moles=.550/molmassCaCO3 +.110/molmassMg(OH)2 price per mole= 9.44/moles Do this for the other two. C. moles=1.200/molmassMg(OH)2 Price /mole=9.99/molemassMg(OH)2 Now,because the acid neutralizing of all three is the same on a ...
  59. math

    and your thinking is?
  60. science

    cfu/ml = (no. of colonies x dilution factor) / volume of culture plate=372*105 /1ml
  61. biology

  62. biology

    No, of course not.
  63. science

  64. Some algebra please help me!

    Did you have fun guessing on these?
  65. Physics

    initial work=initial KE 2.7e-4=1/2 mass*(v^2) solve for v. b. max height PE=initial KE mgh=initial work solve for height h.
  66. biology

    what would happen if we had a cold climate? Sun still shines...
  67. Algebra 2 Explict Rule

    ao=-1; an=a(n-1)+4
  68. Bit rate and probability

    Attention, please show the calculations in details, comments have to be provided.>> No kidding. I had to do this already in Grad School, Information Theory. Your turn. I can't imagine anyone doing this for you.
  69. As Chemistry

    Chemistry - bobpursley Saturday, September 30, 2017 at 10:41am assume you have 100 grams. It becomes the overused algebra candy mixture problem. 60*121+40*X=121.8*100 solve for x I am just a bit miffed: Here is what I told you to do: 60*121+40*X=121.8*100 40x=12180-7260=4920 x...
  70. Science

    Trisomy 21 (47,XX,+21) is caused by a meiotic nondisjunction event.
  71. science

    gravity is directly proportional to mass and the reciprocal of radius squared. If you dont understand, see law of gravity.
  72. science

    Your answer is wrong.
  73. science

    gravity field: 9.8N/kg * (16.7/3.89^2)=10.8 m/s^2 check that
  74. Math please help

    I can't draw graphs here.
  75. English

    On 1, "a" is the correct choice. The word congressman need not be capitalized unless it is a title, or is is a specific congressman. Such as in Congressman Dufus. But in text, congressmen are a dime a dozen, not specific nor capitalized.
  76. Physics

    no knowing whether a phase shift has occurred at both or just one boundary, it could be bright or dark.
  77. Chemistry

    The reaction will occur at room temps, but elevated favors the reverse reaction.
  78. Chemistry

    yes, with photoreactions, or with Molybdenum complexes. These reactions are well documented (see your friend google)>
  79. Chemistry

    It is correct.
  80. Physics

    Thanks for the information. Do you have a question?
  81. Biology Calculation

  82. physics

    work=force*distance against the force - mass*9.8N/kg*30m put in mass of 32kg, and you have the answer in Joules.
  83. american government

    I am wondering how a third party give an independent a shot at the that person with the third party or not? Independent, to me, is independent.
  84. american government

    Mail in are self-selecting. Wasn't that one of the errors in the Truman-Dewey race in 1948?
  85. ElA / Who Knows if The Moons

    I hope you change your posted name.. a) before you get a girlfriend, or b) before you apply for a credit card, or c) before you submit your first college application. The name does not speak well of you or your character. Is it a name you want your friends to remember?
  86. Physics

    force=thrust=mg massrate*v=mg 60kg/sec*v=4000kg*9.8N/kg solve for v
  87. Electronics

    A=A1*A2*A3... but with attenuators, it is fractional, ie 1/20 . Now in log format (ie, db gain), of course, if A=A1+A2+A2 , and the factor is negative for an attenuator.
  88. Science

    What is wheat?
  89. physics/electrical circuits

    I don't need the practice either. Find the circuit current by shorting the output, in my mind I get 6amps. Open circuit voltage is 3 volts. So Norton is a six amp supply feeding a parallel resistor of 1/2 ohm. Is that so difficult?
  90. Calculus

    y=x^4 dy=4x^3 dx=4(1)(.1)=.4 deltay= (x+dx)^4-x^4 = x^4+4dx*x^3+6dx^2*x^2+4dx^3*x+ dx^4 -x^4 check that = 4(.1)1+6(.01)1 + 4(.001)1+(.0001)= =.4641 check
  91. Chemistry

    7. Sr zero/Sr+2 lost two electrons O in O2 zero/ O -2 gained two electrons 8. Cs zero/Cs +1 lost an electron Br in Br2 zero/Br-1 gained an electron
  92. Chemistry

    what you have to do, is write out the reactions, and see if any of the species CHANGED oxidation state. If so, it is a rEDOX reaction.
  93. English

    Actually, "Programs" dont provide anything. Perhaps it is the hospital he is assigned, or his Med School has it covered, somebody pays. I suspect it is the hospital which employs him. You could word is "His family and he have health insurance while he is a ...
  94. physics

    Ok, I get it. Sum of vertical forces=0 4*9.8=T1*sin40+T2*sin60 sum of horizontal forces is zero. T1*cos40=T2*cos60 two equations, two unknowns. Can you do it form here? I recommend substutution.
  95. Physics

    If they are on the same rotatonal axis, addthem to get momentum. Then since momentum is conserved, set that equal to added moments of inertia*final angular velocity.
  96. physics

    at constant velocity? or is it increasing velociy?
  97. SS

    what do you think? Why is Walmart successful?

    the first, aren't the answers all the same? The other three, all wrong.
  99. Physics

    angular momentum is conserved: intertia1*w1=inertia2*w2 4*15=7.5*w2 w2= go to the head of the class,you are right.
  100. Literature

    divorce is only one form of separation. There are many other forms: segreation, non-communication, social stigma (I remember how a pregnant teen described how socially isolated she was because no one would talk or be friends with her. Death is another traumatic separation, ...
  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>