R_scott

Newest questions and responses by R_scott
  1. Science

    google ... how-do-you-calculate-freezing-point-depression

    posted on March 22, 2019
  2. math/pre-calc

    tmax lies on the axis of symmetry of the parabola ... -b / 2a ... -100 / (2 * -4.9)

    posted on March 22, 2019
  3. Science

    a few need rework ... gravity seems to be a theme here Tides are caused by A) gravity. B) heat. C) waves.

    posted on March 22, 2019
  4. Physics

    final energy = initial energy + energy from gravity 1/2 m Vf^2 = 1/2 m 16.0^2 + (m * 9.8 * 27.5) Vf^2 = 256 + (2 * 9.8 * 27.5)

    posted on March 21, 2019
  5. Math

    yd^3 = 27 ft^3 3 ft^3 / (4 * 27 ft^3) = ?

    posted on March 20, 2019
  6. Precalculus

    9/365 * 2 * π * 93 million

    posted on March 20, 2019
  7. math

    1 foot by 1 1/2 foot

    posted on March 20, 2019
  8. Math

    find the rate of fall ... (change in altitude) / (change in time) ... this is the slope of the line ... y = m x + b plug in one of the time/altitude points to find the y-intercept (b)

    posted on March 20, 2019
  9. Quadratics

    you have three equations and three unknowns ... the unknowns are ... a, Vo, and So 144 = 1/2 a (.5^2) + Vo .5 + So 152 = 1/2 a (1^2) + Vo 1 + So 128 = 1/2 a (2.5^2) + Vo 2.5 + So solve the system for a, Vo, and So ... use the resulting equation to find max

    posted on March 20, 2019
  10. Math- Algebra

    revenue = (500 - 20 x)(45000 + 5000 x) ... = 22500000 +1600000 x - 100000 x^2 xmax = -1600000 / (2 * -100000)

    posted on March 20, 2019
  11. Math

    L + 2 W = 120 ... L = 120 - 2W area = L * W = (120 - 2W) * W = 120 W - 2 W^2 the maximum is on the axis of symmetry ... -b / 2a Wmax = -120 / (2 * -2) substitute back to find Lmax

    posted on March 20, 2019
  12. Physics

    final speed = acceleration * time

    posted on March 20, 2019
  13. math

    the radius is 10 cm (think about it) volume = π * radius^2 * height

    posted on March 20, 2019
  14. Algebra 2

    from a z-score table the lower 20% is below ≈.842 σ

    posted on March 20, 2019
  15. Science (Physics)

    reaction distance = speed * reaction time

    posted on March 20, 2019
  16. Math

    v = 1/3 * area of base * height = 1/3 * π * r^2 * h the diameter is twice the radius

    posted on March 20, 2019
  17. Science

    due to the Earth's axial tilt , constellations appear to move higher or lower in the sky, depending on the season

    posted on March 20, 2019
  18. Physics

    heat = mass * specific heat * temperature change do the Al and Fe separately

    posted on March 20, 2019
  19. Science

    average speed = 62.4 m / 4.20 s = (initial + final) / 2 change in speed = -5.60 m/s^2 * 4.20 s = initial - final solve the system for final

    posted on March 20, 2019
  20. maths

    percent growth = [(change in height) / (starting height)] * 100%

    posted on March 20, 2019
  21. Math

    a 4th order equation usually has 4 solutions b^4 + 2b^2 - 24 = 0 ... (b^2 + 6)(b^2 - 4) = 0 b^2 + 6 = 0 ... b = ± i √6 b^2 - 4 = 0 ... b = ± 2

    posted on March 20, 2019
  22. Chemistry

    you're on the right track ... n is the total number of moles use the percentages to find the moles of each gas ... they have different heat contents

    posted on March 19, 2019
  23. math

    2 * [(5 * 7) + (7 * 3) + (3 * 5)]

    posted on March 19, 2019
  24. Chemistry

    the partial pressures are proportional to the mole fractions ... twice the moles, twice the partial pressure ... etc.

    posted on March 19, 2019
  25. Algebra 2

    the maximum of the parabola lies on the axis of symmetry ... t = -b / 2a = -40 / -32 = 1.25 plug that into the height equation to find the max height

    posted on March 18, 2019
  26. math

    umm ... you only got half of the surface area

    posted on March 18, 2019
  27. Trig

    15% grade means that the tangent of the elevation angle is .15

    posted on March 18, 2019
  28. physics

    work done by person ... 95.6 N * cos(35º) * .750 m work done by friction ... 75.5 N * .750 m the difference in the two work amounts is the kinetic energy of the box K.E. = 1/2 * mass * speed^2

    posted on March 18, 2019
  29. Physics

    work = force * distance

    posted on March 18, 2019
  30. Newtonian Mechanics

    1st part ... forces are m*g , distances are given 2nd part ... same forces ... distances are reduced by geometry ... distances equal to 1st part multiplied by sin(45º)

    posted on March 18, 2019
  31. Newtonian Mechanics

    alternately use support 1 and support 2 as a fulcrum calculate the moments the mass of the beam acts in the center

    posted on March 18, 2019
  32. math

    looks good

    posted on March 18, 2019
  33. Math

    Volume = π r^2 h = 3.14 * 10^2 * 12 weight = V * 62.43

    posted on March 17, 2019
  34. Algebra

    general circle equation ... (x - h)^2 + (y - k)^2 = r^2 circle centered at (h,k), with radius r

    posted on March 17, 2019
  35. Calculus

    a trig substitution is used when calculating the integral as oobleck says, it's a standard trick

    posted on March 17, 2019
  36. math

    yes

    posted on March 17, 2019
  37. math

    the 2nd answer is correct ... use it to fix the 1st answer

    posted on March 17, 2019
  38. Math

    s = smaller pump fill time ; b = bigger pump fill time s = b + 120 (144 / s) + (144 / b) = 1 [144 / (b + 120)] + (144 / b) = 1 144 b + 144 b + (144 * 120) = b (b + 120) 0 = b^2 - 168 b - 17280 convert answer to hours

    posted on March 17, 2019
  39. geometry

    if the sum of the two smaller sides is ≤ the largest side ... a triangle cannot be made (won't close up)

    posted on March 16, 2019
  40. science

    acceleration is changing speed, which falls under kinetic energy

    posted on March 16, 2019
  41. math

    looks good

    posted on March 15, 2019
  42. math

    the two lines mean "absolute value" ... just the number , no sign

    posted on March 15, 2019
  43. math

    you plug the point into the equation and see if the equation is true x = 7 , y = 1

    posted on March 15, 2019
  44. Math

    for each revolution of the tire , the bicycle travels ... 2.5 π ft revs = 5280 / (2 π)

    posted on March 15, 2019
  45. Algebra

    it's arithmetic , so the missing term is the average of the ones on either side

    posted on March 14, 2019
  46. Algebra

    9 ft * .8^3

    posted on March 14, 2019
  47. physics

    by throwing the wrench away from the spaceship , she will give herself momentum towards the ship to me , this seems more like the 3rd law ... action/reaction

    posted on March 14, 2019
  48. math

    0.275 x = 55 solve for x

    posted on March 14, 2019
  49. Math

    parallel means the lines have the same slope ... their m's are equal y = 4 x + b ... through (1,6) plug in the point , and solve for b ... y = 6 , and x = 1

    posted on March 14, 2019
  50. science

    try googling "rabbits in Australia"

    posted on March 14, 2019
  51. Physics

    π/4 is the launch angle for maximum range on a level surface the vertical component of the launch velocity would be ... U √2 / 2 kinetic energy at launch is potential energy at peak ... U^2 / 4 = g h solve for h

    posted on March 14, 2019
  52. chemistry

    1. moles = mass / atomic mass = 6.3 / 27 2. atoms = moles * Avogadro's number = moles * 6.02E23

    posted on March 13, 2019
  53. Math

    what happened to the y that was already in the 1st equation?

    posted on March 13, 2019
  54. Science

    acceleration = (change in speed) / (change in time) 2nd one looks good

    posted on March 12, 2019
  55. Algebra

    x * .18 + (10 - x) * .40 = 10 * .20

    posted on March 12, 2019
  56. Math

    1. yes ... it is the result of multiplying the equation by -1 2. no ... the left side can come from multiplication by -1 BUT ... changing a single sign in the right side polynomial is not a legitimate operation

    posted on March 12, 2019
  57. Science

    _o_m_l_ VERY generous hint

    posted on March 11, 2019
  58. math

    you are correct (90 - 75) / 75 = 20%

    posted on March 11, 2019
  59. Science

    most meteors are chunks of comets that enter the Earth's atmosphere

    posted on March 11, 2019
  60. science

    power = energy / time watt = joule / second

    posted on March 11, 2019
  61. science

    speed = frequency * wavelength keep your units consistent ... m / km

    posted on March 11, 2019
  62. math

    step 2 is incorrect subtracting 10 ... 2m^2 - 7m - 23 = 0

    posted on March 10, 2019
  63. chem

    energy = specific heat * temperature change make sure all your units are compatible ... joules , grams , ºC , specific heat

    posted on March 10, 2019
  64. Stats

    the z-score is the distance from the mean, measured in standard deviations points distance = z-score * σ

    posted on March 10, 2019
  65. Math

    An becomes f(n) ... distributing the 6 ... 6n + 12 f(n) = 6 n + 12

    posted on March 9, 2019
  66. Math

    n ≥ 2 looks like you're starting at 18, and adding 6 to each consecutive term An = 6 (n + 2)

    posted on March 9, 2019
  67. math

    plug in the values 1, 2, 3, and 4 for n , and calculate the resulting terms

    posted on March 9, 2019
  68. Math

    A = n B + k 15 = 2 n + k 45 = 8 n + k subtracting equations ... 30 = 6 n solve for n , then substitute back to find k

    posted on March 9, 2019
  69. Math

    looks good

    posted on March 9, 2019
  70. mATH

    draw a sketch and use the Pythagorean theorem BIG HINT ... it's a 3-4-5 triangle

    posted on March 8, 2019
  71. Math

    how many fish did she catch? how many were trout? ... what fraction?

    posted on March 8, 2019
  72. Algebra

    square the binomial and compare the results to find k (2x-3)^2 = 4x^2 - 12x + 9 (2x-3)^2 + k = 4x^2 - 12x + 13 check your calculations

    posted on March 8, 2019
  73. Science

    read the "protist" article on wikipedia

    posted on March 7, 2019
  74. Algebra

    there's only one rational number in the list ... you didn't pick it

    posted on March 7, 2019
  75. Physics

    f = G * M1 * M2 / d^2 the masses are listed in Newtons, a force unit ... maybe a typo? the gravitational force equation uses mass ... is this happening on Earth? ... is g need for conversion?

    posted on March 6, 2019
  76. Physics

    1st part ... d = 12 m/s * 30.0 s 2nd part ... ave speed = {12 m/s + [12 m/s + (1.5 m/s^2 * 8.00 s)]} / 2 ... d = ave speed * 8.00 s 3rd part ... top speed = 12 m/s + (1.5 m/s^2 * 8.00 s) ... d = top speed * 12.0 s add the displacements for the total

    posted on March 6, 2019
  77. math

    start with easy and go to harder, if you have to assume a linear function ... y = m x + b when x is 0 , y is -1 ... so b is -1 when x is -2 , y is 9 ... 9 = -2 m - 1 ... 10 = -2 m ... m = -5 when x is 2 , y is -11 ... -11 = 2 m - 1 ... -10 = 2 m ... m = -5

    posted on March 6, 2019
  78. math

    no input? arithmetic means add or subtract ... geometric is multiply or divide how do you get from one number to the next? what would be the next three numbers

    posted on March 6, 2019
  79. math

    yes ... I do believe "clueless" substitute the values 1, 2, 3, and 4 for "n" in the given expression

    posted on March 6, 2019
  80. Science

    from google ... abiotic ... "physical rather than biological; not derived from living organisms" if copper interferes with photosynthesis (a plant thing) , why B? maybe one person's rude , is another's tough love

    posted on March 6, 2019
  81. math

    try plugging in one thru four for n

    posted on March 6, 2019
  82. Geometry

    no givens...

    posted on March 6, 2019
  83. Math- please help

    is there a relationship sign (like =, ≥, ≤, or something) missing?

    posted on March 6, 2019
  84. science

    no diagram the 30º angle makes the most sense with the ceiling so the horizontal string force is ... m g sin(Θ) ... this is equal to the force of the electric field on the ball force = field strength * ball charge

    posted on March 6, 2019
  85. Science

    where are they?

    posted on March 5, 2019
  86. math

    no correction needed

    posted on March 5, 2019
  87. math

    yes

    posted on March 5, 2019
  88. Math 6th grade

    the + is between the number and two multiplication takes precedence (it happens first) over addition

    posted on March 5, 2019
  89. math

    Damon ... look at the time stamps ... the answers are appearing almost simultaneously ... good group effort reality has to out shout stupidity

    posted on March 5, 2019
  90. math

    the two spins are independent events P(vowel) = 1/3 P(K) = 1/6 multiply the probabilities

    posted on March 5, 2019
  91. math

    P(red) = 8/43 P(blue) = 12/43 multiply the two probabilities (independent events)

    posted on March 5, 2019
  92. math

    odds are different than probability ... favorable : unfavorable the probability of green is ... 6/11 the odds of green is ... 6:5

    posted on March 5, 2019
  93. Chemistry

    looks good you might want to be aware of significant figures

    posted on March 5, 2019
  94. math

    yes half of the numbers are even (divisible by 2)

    posted on March 5, 2019
  95. Algebra

    there are eight cards in the hat , three of them with an I , five with another letter 3 I's , 5 not .. the odds of an I are 3:5

    posted on March 5, 2019
  96. Math

    there are 6 ways to get doubles on the dice ... any of the six numbers on both dice ... 1-1, 2-2, 3-3, 4-4, 5-5, 6-6 there are 36 possible outcomes from rolling the dice ... any of the six numbers on one die, with any of the six numbers on the other die

    posted on March 5, 2019
  97. science

    heat gained by water = heat lost by metal amount of heat = mass * specific heat * temperature change

    posted on March 5, 2019
  98. Math

    it sounds like doubles on the dice...not any specific number her chances of winning are the same with both one number out of six on the wheel ... or 6 chances out of 36 with the dice

    posted on March 5, 2019
  99. Math

    red (w/discount) ... $18 per gallon blue (w/discount) ... $20 per gallon (3 n * 18) + (2 n * 20) ≤ 500 54 n + 40 n ≤ 500 ... 94 n ≤ 500 ... n ≤ 5 15/47 3 n = 15 gal red ... 2 n = 10 gal blue

    posted on March 4, 2019