Popular questions and responses by craig
  1. chemistry

    Strong base is dissolved in 665 mL of 0.400 M weak acid (Ka = 3.69 × 10-5) to make a buffer with a pH of 3.94. Assume that the volume remains constant when the base is added. HA(aq) + OH-(aq) -> H2O(l) + A-(aq) Calculate the pKa value of the acid and

    asked on July 8, 2012
  2. Algebra 1

    The upward velocity of the water in the stream of a particular fountain is given by the formula v = -32t + 28, where t is the number of secondds after the water leaves the fountain. While going upward, the water slows down until, at the top of the stream,

    asked on October 11, 2007
  3. math

    a rectangular pen is to be constructed alongside a barn using 120 feet of fencing. the barn will be used for one side of the pen. What should the dimensions of the pen be to maximize its area. ***Can not use calculus. This is a 9th grade question

    asked on September 28, 2011
  4. Calculus

    For an object whose velocity in ft/sec is given by v(t) = -3t2 + 5, what is its displacement, in feet, on the interval t = 0 to t = 2 secs? 6.607 2 -2.303 2.303

    asked on June 19, 2018
  5. Calculus (related rates)

    A ladder 13 meters long rests on horizontal ground and leans against a vertical wall. The foot of the ladder is pulled away from the wall at the rate of 0.4 m/sec. How fast is the top sliding down the wall when the foot of the ladder is 5 m from the wall?

    asked on March 21, 2017
  6. college math

    How many different committees can be formed from 9 teachers and 39 students if the committee consists of 2 teachers and 3 students? In how many ways can the committee of 5 members be selected?

    asked on March 24, 2013
  7. math

    what is the unit rate for 250 miles in 5 hours

    asked on May 11, 2010
  8. Chemistry

    Complete the following equilibrium reactions that are pertinent to an aqueous solution of Ag2CO3. Physical states, s, l, g, and aq, are optional. So far I worked it out to be: Ag2CO3(s) 2Ag^+ + CO3^(2-) H2CO3(aq) + H2O(l) H3O^(1+) + (HCO3)^(-) HCO3^(-)(aq)

    asked on April 6, 2016
  9. Math

    Matt has twice as many stickers as David. If David has d stickers, and Matt gives David 10 stickers, how many stickers does each have in terms of d?

    asked on February 20, 2009
  10. Maths

    When you flip a biased coin the probability of getting a tail is 0.6. How many times would you expect to get tails if you flip the coin 320 times?

    asked on April 6, 2019
  11. Trigonometry

    Which interval gives an average change of 0 for the function y = 3cos (4πx + π) - 3? a) π/3

    asked on June 18, 2020
  12. Calculus (related rates)

    Find dy/dt when y = 2x2 + 2x + 4 and dx/dt = 14 when x = 7.

    asked on March 21, 2017
  13. Chemistry

    Methane reacts with water to form CO and H2 as follows: CH4(g)+H2O(g)=CO9g)+3H2(g) The value of Kp at 298 k for the reaction is 7.7 *10^24, calculate Kc. If you can please show the steps I would greatly appreciate it. Thank you

    asked on December 10, 2013
  14. chemistry lab

    How does the presence of a common ion affect the solubility of a salt? Explain in terms of equilibrium.

    asked on July 9, 2012
  15. ALGEBRA 1

    The square of a number is equal to the sum of 21 and 4 times the number. Find the number

    asked on January 4, 2012
  16. algebra

    Use the given conditions to write an equation for the line in point'slope form and slope-intercept form. Slope= -5, passing through (-9,-6) type the point-slope form ot the line Type the slope-intercept form of the line

    asked on June 6, 2011
  17. Math

    If I bought an item for $80 on which there was a 30% markup, what is the formula to determine the pre-markup price?

    asked on July 12, 2010
  18. Statistics

    An investigational drug study is being conducted. The initial screening phase needs to include enough people so that the final (approved) group has at least 10 patients. The probability of a person being approved for the study is .80. what initial sample

    asked on June 6, 2009
  19. IT

    high level languages need to be translated. what are two different types of translator? Thank you for using the Jiskha Homework Help Forum. By your question do you mean human vs. mechanical (machine or computer-assisted) translation?

    asked on February 22, 2007
  20. math

    The average cost to attend a particular university in 1969 was $592 and in 2009 was $17,058. Let y be the average cost in the year x, where x = 0 represents the year 1969. Write a linear equation, in slope-intercept form, that models the growth in cost at

    asked on November 17, 2017
  21. math

    The number of boxes on a truck varies directly with the time since the workday began. At 3 hours after the workday began, there are 207 boxes on the truck. How many boxes should we expect there to be on the truck hours after the workday began? Show the

    asked on November 14, 2017
  22. math

    Ron would like to have at least $150,000 saved to buy a condo. If he invests $50,000 in an account paying 6.19% interest compounded quarterly, will he reach his goal in 15 years? Show all work to justify your answer and include appropriate units.

    asked on November 5, 2017
  23. Calculus (related rates)

    Find dy/dt where y = 2 sqrt(x)-4 and dx/dt = 9 when x = 4.

    asked on March 21, 2017
  24. Math

    If Tyrone tips Sharqueffa $500 and Daquan tips Watermelondrea $600, how much did the trap house earn that night if Cellularphoniqua (the owner) takes 10% of all tips. Please help

    asked on October 6, 2016
  25. physics

    an arrow is shot vertically upward after 2s it is at a height of 36m although this is not necessarily the highest point with what velocity was the arrow shot what is the maximum height reached by the arrow how long is the arrow in flight altogether

    asked on July 26, 2016
  26. physics

    the takeoff speed for a large airplane is 180 mi/hr(roughly 80m/s0 the plane is capable of accelerating at a rate of 4m/s^2 assume that the plane starts at rest determine the minimum runway length required for this plane to safely take off a smaller

    asked on July 26, 2016
  27. maths

    marcus has a box of chocolates. he eats 1/5 of them. his sister eats 1/3 of the chocolates that are left. there is 24 chocolates left in the box. how many where in the box to start with.

    asked on July 1, 2016
  28. Math

    the current population of a city is 45000 and is increasing according to P=45000(1+t)^n and n=number of years. if the rate of increase is 7.5% how long will it take the population to double?

    asked on April 25, 2016

    How do the following terms relate to one another with respect to a single genetic locus? - Wild Type Allele(s) - Mutant Allele(s) - Gene Product(s) - Population - Genotype - Phenotype - Dominant Allele - Recessive Allele - Individual - Number of different

    asked on February 28, 2016
  30. Math

    The cost-of-living index increased from 100 to 120. What effect does this have on the purchasing power of the dollar?

    asked on February 25, 2016
  31. Math

    a 5 foot fence will be built around the perimeter of a 50 foot by 120 foot rectangular lot. if the fence costs $1.80 per linear foot for labor and $.40 per square foot for material, what will be the cost of the fence?

    asked on February 24, 2016
  32. statistics

    The average cost per night of a hotel room in New York City is $272 (SmartMoney, March 2009). Assume this estimate is based on a sample of 45 hotels and that the sample standard deviation is $65.

    asked on December 9, 2015
  33. Algebra 2

    Show two steps to simplify each of the following expressions, and then calculate the value of each expression. 25 exponent 5/2 81 exponent 7/4

    asked on November 3, 2015
  34. OJTC

    if a car was traveling 60 miles an hour and hit and in movable wall instantaneously stopping how many gravities of force would be involved

    asked on October 22, 2015
  35. Geometry

    How do you figure the height of a tripod using 28' legs set 7' out from center?

    asked on May 18, 2015
  36. Math

    What is the equation 745✖876

    asked on October 29, 2014
  37. algebra

    Question: 89 of 111 Leave Questionnaire You need to hire a part-time associate to work 30 hours a week in your store. You have $250 in labor budget for the new associate each week. You just interviewed an excellent candidate for the position who has

    asked on June 4, 2014
  38. math


    asked on February 21, 2013
  39. physics

    How much friction force will be required if a car weighing 2100kg traveling at 28m/s rounds a curve of radius 59m banked at a 15 degree angle

    asked on September 25, 2012
  40. physics

    in the equation V=sqrt(r*g), what does sqrt stand for?

    asked on September 25, 2012
  41. Math

    3x-2y=0 x-y=-1

    asked on July 12, 2012
  42. Geography

    What political changes swept through Europe during the second half of the twentieth century?

    asked on January 9, 2012
  43. MATH

    the perimter of a rectangle is 20inches and its area is 16 square inches. Find the dimensions of the rectangle. I need help to set up the problem

    asked on January 5, 2012
  44. ALGEBRA 1

    The height h is the time of seconds that the ball has been in the air with an initial vertical velocity of 48 feet per second from a height of 5 feet above the ground is given by the equation h=-16t^2 + 48t + 5 where t is the time in seconds that the ball

    asked on January 3, 2012
  45. math

    Im having a problem understanding this problem so I cant solve it. Bruce knows how many key are on his keyboard, but some don't work. How does Bruce find the number of keys that work? write to explain

    asked on December 7, 2011
  46. Biology

    Why does Beta Glucose chains have more weak bonds between the chains than there are between alpha glucose chains?

    asked on October 9, 2011
  47. Managerial Accounting

    what management position is responsible for each variance: Sales Materials Labor Overhead General, Selling & Administrative What causes these variances?

    asked on April 5, 2011
  48. Chemistry

    A solution is prepared by dissolving 130 g of NaNO3 in 100 g of water at 80°C. The solution is cooled to 0°C. How many grams of compound remain in solution? How may grams of solid are formed?

    asked on April 3, 2011
  49. math

    What is 58 rounded to the greatest place value?

    asked on February 3, 2011
  50. Math

    The number is between 3 and 10, you can make exactly 3 arrays with this number and it's not 9. What is it?

    asked on December 5, 2010
  51. Math (Calc 1)

    Consider a window the shape of which is a rectangle of height h surmounted a triangle having a height T that is 1.3 times the width w of the rectangle (as shown in the figure below). (pictures of a pentagon) If the cross-sectional area is A, determine the

    asked on November 20, 2010
  52. Biotechnology

    How would you make 450 mL of a 0.250 M NaOH solution?

    asked on November 13, 2010
  53. English

    I believe in this sentence: It was the world’s first movie studio. the subject is: movie studio the predicate is: was Am I correct?

    asked on September 29, 2010
  54. English

    The first movies were different from today’s films. What is the simple predicate

    asked on September 29, 2010
  55. math

    n=1/a-1/b solve for b please show all steps

    asked on September 16, 2010
  56. maths.

    find the lcd of each setof fractions: 1/2, 1/8, 1/16

    asked on September 11, 2010
  57. Marketing

    A manufacturer of AC units realizes a cost of $55.00 for every unit produced. Its total fixed cost is $2,000,000. If the manufacturer produces 500,000 units, calculate its: a. unit cost b. markup price if it desires a 10% returns on sales c. ROI price if

    asked on July 12, 2010
  58. Alge.

    Graph the equation using the slope and the y-intercept. y=5/3x+2 I need to show the slope and y-intercept when I graph.

    asked on May 26, 2010
  59. Math

    Is there a difference between solving a system of equations by the algebraic method and the graphical method? Why or why not?

    asked on March 10, 2010
  60. french

    can someone check my french essay on pocket money and improve where possible very much appreciated Je recois dix livres d'argent de poche par semaine de mes parents. Pour gagner mon argent de poche je dois aider mes parents a la maison et je dirais que

    asked on March 7, 2010
  61. science

    a snowball rolls off the edge of a horizontal roof at a velocity of 7 m/s. what is the speed of the snowball 3 s later?

    asked on November 3, 2009
  62. physics

    what is the angular speed of Earth around the Sun in radians per second

    asked on October 9, 2009
  63. law

    according to beccaria, the system can reduce the severity of punishment and it can also do what?

    asked on September 10, 2009
  64. Math Statistics

    An investigational drug study is being conducted. The initial screening phase needs to include enough people so that the final (approved) group has at least 10 patients. The probability of a person being approved for the study is .80. what initial sample

    asked on June 6, 2009
  65. Algebra

    I'm trying to solve this equation for x. .6 = x / x + 20 I can tell that X=30, but how do I prove that mathematically? We can't just plug in numbers, we have to show where we got them from.

    asked on February 16, 2009
  66. trigonometry

    show that 1-cos^2t divided by sin^2t =TANt

    asked on January 30, 2009
  67. trigonometry

    1) show that: 1-cos2t divided by sin2t= TANt 2) show that: 1-(cos2t divided by (cos x cos)t)= (TAN x TAN)t

    asked on January 28, 2009
  68. Calculus

    t: 0 2 5 7 11 12 r'(t): 5.7 4.0 2.0 1.2 0.6 0.5 The volume of a spherical hot air balloon expands as the air inside the balloon is heated. The radius of the balloon in feet is modeled by a twice-differentiable function of r of time t, where t is measured

    asked on November 25, 2008
  69. Need help fast on calc

    original curve: 2y^3+6(x^2)y-12x^2+6y=1 dy/dx=(4x-2xy)/(x^2+y^2+1) a) write an equation of each horizontal tangent line to the curve b) the line through the origin with the slope .1 is tangent to the curve at P. Find x and y of point P. -when plugging y as

    asked on November 12, 2008
  70. Math

    How do you do a factor tree for 37?

    asked on October 30, 2008
  71. 8th grade


    asked on September 18, 2008
  72. math

    Factoring. 6n^2 +24n -18 Answer: 6(n^2 +4n -3) y^3 -y^2 + 3y -3 Answer: (y-1)(y^2 +3)

    asked on August 21, 2008
  1. physics


    posted on March 19, 2018
  2. math


    posted on February 4, 2018
  3. math

    Sorry.. The number of boxes on a truck varies directly with the time since the workday began. At 3 hours after the workday began, there are 207 boxes on the truck. How many boxes should we expect there to be on the truck 7 1/3 hours after the workday

    posted on November 16, 2017
  4. math

    Thanks Scott! Could you possibly break the format down a little more? Did he reach his goal and the units.

    posted on November 5, 2017
  5. Calculus (related rates)

    FORMAT WRONG ABOVE.... Correct one is.. Find dy/dt when y = 2x^2 + 2x + 4 and dx/dt = 14 when x = 7.

    posted on March 21, 2017
  6. English

    In "Mowgli's Brothers," before he leaves the jungle, Mowgli says, "For the rest, Akela goes free to live as he pleases. Ye will not kill him." What does this show about Mowgli?

    posted on January 4, 2017
  7. 12 math

    c)3! x 6! The three must remain together but can be in any permutation with the rest. It would be 5! ways if the three books had to be in a certain position.

    posted on December 1, 2016
  8. Math

    I think its $990 after Cellularphoniqua takes 10%

    posted on October 6, 2016
  9. Chemistry

    Anyone please?

    posted on April 7, 2016
  10. Math

    I figured it out. 40 acres = 1320' x 1320'; P=2L + 2W; P=2(1320)+ 2(1320); P=5,280', which is a mile. Run the wire 3x, and it equals 3 miles.

    posted on February 25, 2016
  11. Math

    I figured it out. 120-100=20, which is the net difference. Divide net difference by the new cost of 120, which equals 16.67 less.

    posted on February 25, 2016
  12. Math

    I can't calculate the correct answer.

    posted on February 25, 2016
  13. Math

    Thank you for the response. That was the answer that I initially calculated using percentage change; however, the answer is that it was lowered by 16 2/3%. The explanation is that it now takes $6 to buy what used to cost $5. Each dollar is worth 1/6 less.

    posted on February 25, 2016
  14. math

    which to end unit is the best choice for measuring the pyramid of a picture on the wall

    posted on April 28, 2015
  15. statistics


    posted on April 15, 2014
  16. Math- urgent

    8x-8-6x=20 2x=28 x=14

    posted on December 10, 2013
  17. Math


    posted on July 7, 2013
  18. how to sketch a graph of..


    posted on June 23, 2013
  19. chemistry lab

    Oh that's what it is? Thanks

    posted on July 10, 2012
  20. Statistics

    What spinner?

    posted on July 8, 2012
  21. chemistry

    thank great help! much appreciated

    posted on July 8, 2012
  22. geometry

    a right triangle find the value with 71 5 find x n y answers

    posted on January 30, 2012

    ok fine ,but thanks for the help

    posted on January 5, 2012

    He is right if romeo and juliet get married and the families might come together. The Friar does consent to marry Romeo and Juliet, hoping that the marriage might bring peace between the feuding families. Is this right so far.

    posted on January 5, 2012
  25. Social Studies

    Improve Not all early Americans were happy with the Constitution. Democratic-Republicans, also known as Anti-Federalists, opposed the Constitution because they feared the Federal Government would gain too much power... much like King George from whom they

    posted on January 4, 2012
  26. algebra

    A farmer decides to enclose a rectangular garden, using the side of a barn as one side of the rectangle. What is the maximum area that the farmer can enclose with 120 ft. of fence? What should the dimensions of the garden be to give the farmer the max

    posted on September 28, 2011
  27. chemistry

    stop cheating

    posted on November 15, 2010
  28. English


    posted on September 29, 2010