Popular questions and responses by katie
  1. Physics

    The motion of a piston in an automobile engine is nearly simple harmonic. If the 1-kg piston travels back and forth over a total distance of 10.0 cm, what is its maximum speed when the engine is running at 3 000 rpm? The answer is 15.7 m/s but I don't

    asked on July 9, 2010
  2. Statistics

    A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 30 minutes. The

    asked on November 8, 2013
  3. chemistry

    At 25 °C only 0.0580 mol of the generic salt AB3 is soluble in 1.00 L of water. What is the Ksp of the salt at 25 °C?

    asked on February 13, 2012
  4. Physics

    How long will it take a charged 80-ìF capacitor to lose 20 percent of its initial energy when it is allowed to discharge through a 45 ohm resistor?

    asked on May 22, 2011
  5. chemistry

    Write the balanced chemical equation for each of these reactions. Include phases. When aqueous sodium hydroxide is added to a solution containing lead(II) nitrate, a solid precipitate forms. However, when additional aqueous hydroxide is added the

    asked on February 13, 2012
  6. chemistry

    The rate constant for this first-order reaction is 0.320 s–1 at 400 °C. A--> Products How long (in seconds) would it take for the concentration of A to decrease from 0.830 M to 0.220 M?

    asked on March 23, 2012
  7. Chemistry

    What is the maximum concentration of Ca2+ ions in a solution containing 0.010 M of F- ions?

    asked on May 10, 2012
  8. Chemistry

    Which of the following set of quantum numbers (ordered n, ℓ, mℓ, ms) are possible for an electron in an atom? Check all that apply. -4, 3, 1, 1/2 2, 1, -2, 1/2 4, 2, 1, -1/2 4, 2, -1, -1/2 2, 4, 1, -1/2 5, 3, -3, 1/2 5, 3, 4, 1/2 3, 2, 0, -2

    asked on October 11, 2018
  9. mathematics

    An irrigation drip arm is 28 feet long and pivots about a center one revolution each hour. A “drip hole” H is located 28 feet from the pivot point. (a) What is the linear speed of H in units of feet/hour ,feet/minute ,feet/second , and inches/second .

    asked on July 20, 2020
  10. math

    What is the period, in seconds, of a simple pendulum of length 3 meters? Use the gravitational constant g = 9.8 m/s2 and round your answer to two decimal places Please help! A step by step would with the answer would be helpful!

    asked on June 9, 2014
  11. chemistry

    What is the pH of a 2.8 M solution of HClO4?

    asked on January 22, 2012
  12. chemistry

    Calculate the standard free-energy change for the following reaction at 25 °C. 2Au^3+(aq) + 3Ni(s) -->2Au(s) + 3Ni^2+(aq)

    asked on February 29, 2012
  13. Precalculus

    Let C be a circle that passes through the origin. Show that we can find real numbers s and t such that C is the graph of r = 2s*cos(theta + t) I think that I could start by writing it like R^2=(x-h)^2+(y-k)^2 where R is the radius of the circle, but I

    asked on April 18, 2016
  14. math

    gabriella volunteers 15 hours in a week. How many weeks in a year would that total in? - 10 hrs? - 4 hrs? - 3 hrs? - 2 hrs?

    asked on July 29, 2020
  15. Math

    What are the odds of drawing a 5 from these cards? 1,2,3,4,5 I do not understand how to solve this. Thanks

    asked on September 18, 2016
  16. Trigonometry

    If sin(x) = 4cos(x), then what is (sin(x))*(cos (x))?

    asked on April 4, 2016
  17. college physics

    tennis ball rolls off the edge of a tabletop 0.900m above the floor and strikes the floor at a point 1.60m horizontally from the edge of the table. A: Find the time of flight of the ball B: Find the magnitude of the initial velocity of the ball. C: Find

    asked on September 22, 2014
  18. Statistics

    The monthly incomes from a random sample of workers in a factory are shown below. Monthly Income (In $1,000) 4.0 5.0 7.0 4.0 6.0 6.0 7.0 9.0 a. Compute the standard error of the mean (in dollars). b. Compute the margin of error (in dollars) at 95%

    asked on November 12, 2013
  19. chemistry

    Give the chemical formula for trans-dichlorobis(ethylenediamine)platinum(IV). Use (en) as the symbol for ethylenediamine.

    asked on March 30, 2012
  20. Chemistry

    A solution contains 0.133 g of dissolved Lead. How many moles of soduim chloride must be added to the solution to completly precipitate all of the disolved lead? What mass of sodium chloride must be added?

    asked on May 14, 2011
  21. Math 141

    Two cards are drawn from a well-shuffled deck of 52 playing cards. Let X denote the number of aces drawn. Find P(X = 0). (Round your answer to three decimal places.)

    asked on November 13, 2015
  22. Math

    Suppose p and q are points on the unit circle such that the line through p and q intersects the real axis. Show if z is the point where this line intersects the real axis, then z=(p+q)/(pq+1) So far I've figured out that the equation for the line is

    asked on May 31, 2016
  23. Chemistry

    The FDA recommends that women who are pregnant avoid eating more than three 6.00-oz servings of bluefish per month because of the relatively high mercury levels in that type of fish. If bluefish contains 0.341 ppm of mercury (that is, 0.341 oz of mercury

    asked on February 1, 2014
  24. Chemistry...

    The oxygen gas emitted from an aquatic plant during photosynthesis is collected over water at a temperature of 25 degrees celsius and a total pressure of 762 torr. What is the partial pressure of the oxygen gas? What formula do I need to use?

    asked on February 20, 2013
  25. Trig

    If you are dealt 3 cards from a shuffled deck of 52 cards, find the probability that all 3 cards are picture cards.

    asked on May 7, 2012
  26. physics

    a ball is dropped from the top on an 80-m high building. what speed does the ball have in falling 3.5 s?

    asked on March 30, 2014
  27. physics

    A rock is dropped from a sea cliff, and the sound of it striking the ocean is heard 3.3 later. If the speed of sound is 340 , how high is the cliff?

    asked on September 17, 2010
  28. Math

    The bases on a baseball diamond are 27.4m apart. The pitcher pitches,and the batter hits a fly ball straight up 15m. What is the maximum angle of elevation of the ball to the nearest degree, as seen by the pitcher if he is standing at the center of the

    asked on November 28, 2016
  29. Math

    Gerald can complete a math assignment in 2 hours and a physics assignment in 1 hour. If he has 8 hours to complete a set of assignments, how many math assignments can he complete if he decides to leave the science assignments for the next day? This

    asked on May 27, 2013
  30. MATH

    a pile of bricks has 85 bricks in the bottom row, 79 bricks in the second row, 73 in the third row, and so on until there is only 1 brick in the top row. how many bricks are in the 12th row? how many rows are there in all?

    asked on October 31, 2011
  31. Physics

    What angular speed (in revolutions/second) is needed for a centrifuge to produce an acceleration of 1000g at a radius arm of 15.0cm?

    asked on June 8, 2010
  32. chemistry

    What is the molecular geometry for SH2? 1. Bent 2. Trigonal planar 3. Tetrahedral 4. Liner

    asked on November 29, 2011
  33. Physics

    A small wooden block with mass 0.800kg is suspended from the lower end of a light cord that is 1.52m long. The block is initially at rest. A bullet with mass 0.0126kg is fired at the block with a horizontal velocity v0. The bullet strikes the block and

    asked on March 12, 2015
  34. chemistry

    The reaction described by this equation O3(g) + NO(g) -- O2(g) + NO2(g) has the following rate law at 310 K. rate of reaction = 3.0x10^6 M^-1 s^-1)[O3][NO] Given that [O3]=2.0× 10–4 M and [NO]=2.0× 10–5 M at t=0, calculate the rate of the reaction at

    asked on March 23, 2012
  35. Chemistry

    a) How many moles of atoms are in 7.00 g of 13C? Answer "0.538" mol 13C b) Based on your answer in Part A, calculate the number of atoms in this amount of 13C? Answer "3.24×10^23" 13C atom c) Based on your answer in Part B, how many electrons are in this

    asked on August 25, 2018
  36. literature

    In the merchant of venice act 2 scene 2, Portia gives Bassanio the ring with a warning, and Bassanio accepts the ring with his own pledge. How is this contract or bond similar to and different from the one made in Venice? What significance did rings have

    asked on October 2, 2016
  37. Math: Trigonometry

    For how many values of n with 0

    asked on April 8, 2016
  38. chemistry

    Construct the octahedral crystal-field splitting diagram for the metal in each species. Cr4+ Mn(H2O)6^2+

    asked on March 30, 2012
  39. physics

    A block with mass m = 17 kg rests on a frictionless table and is accelerated by a spring with spring constant k = 4201 N/m after being compressed a distance x1 = 0.556 m from the spring’s unstretched length. The floor is frictionless except for a rough

    asked on March 20, 2018
  40. Math

    - If I spent 15 hours per week volunteering, how many hours in total weeks per year? - 4 hours? - 3 hours? - 2 hours?

    asked on July 25, 2020
  41. Math

    A spinner has 4 equal sections: red, white, blue, and green. john spins the spinner and tosses a coin. which shows the sample space for spinning the spinner and tossing the coin? I have a chart but I cant figure out how to get into this question.

    asked on March 12, 2019
  42. Math

    Which of the following options results in a graph that shows exponential growth A.f(x)= 0.4(3)^x B.f(x)= 3(0.5)^x C.f(x)= 0.8(0.9)^x D.f(x)= 0.9(5)^-x

    asked on November 4, 2015
  43. Chemistry

    The Kc for the following reaction at 940oC is 1.38. Given the concentrations [CO2] = 0.500 M, [H2] = 0.425 M, [CO] = 0.610 M and [H2O] = 0.695 M, one can conclude that: H2(g) + CO2(g) ↔ CO(g) + H2O(g) Question 8 options: A) the system is not at

    asked on May 10, 2012
  44. Chemistry

    A mixture of lead, magnesium, nitrate and chromate ions are present in a solution. What will the precipitate be? Question 2 options: A) MgPb B) Pb(NO3)2 C) PbCrO4 D) MgCO3

    asked on May 10, 2012
  45. Stats Class HELP!

    Twenty-five blood samples were selected by taking every seventh blood sample from racks holding 187 blood samples from the morning draw at a medical center. The white blood count (WBC) was measured using a Coulter Counter Model S. The mean WBC was 8.636

    asked on April 18, 2014
  46. Trig

    How do I solve the following? sec 3 theta/2 = 2 on the interval 0

    asked on March 14, 2010
  47. vectors

    The minute hand of a wall clock measures 11 cm from its tip to the axis about which it rotates. The magnitude and angle of the displacement vector of the tip are to be determined for three time intervals. What are the (a) magnitude and (b) angle from a

    asked on February 2, 2015
  48. Chemistry

    A solution contains an unknown amount of dissolved calcium . Addition of 0.112 mole of K3PO4 causes complete precipitation of all the calcium. How many moles of calcium were dissolved in the solution?

    asked on May 14, 2011
  49. precalc

    Points A, B, and C are on the circumference of a circle with radius 2 such that angle BAC = 45 degrees and angle ACB = 60 degrees. Find the area of triangle ABC.

    asked on July 15, 2016
  50. chemistry

    Which of these ions have five d electrons in the outermost d subshell? Mn2+ Fe2+ Re2+ Y2+ Tc2+ Zn2+ Ru2+

    asked on March 30, 2012
  51. physics

    A satellite moves on a circular earth orbit that has a radius of 6.68E+6 m. A model airplane is flying on a 16.3 m guideline in a horizontal circle. The guideline is nearly parallel to the ground. Find the speed of the plane such that the plane and the

    asked on February 18, 2012
  52. chemistry

    Aerosol cans have a label that warns the user not to use them above a certain temperature and not to dispose of them by incineration. Even an empty can contains residual gaseous propellant. For example, the residual pressure in a can is 1.36 atm when it is

    asked on December 6, 2009
  53. Algebra

    The yearly per capita consumption of whole milk in the United States reached a peak of 40 gallons in 1945, at the end of World War II. By 1970 consumption was only 27.4 gallons per person. It has been steadily decreasing since 1970 at a rate of about 3.9%

    asked on April 9, 2017
  54. English

    What figurative language is "August is a day in the sun

    asked on October 8, 2019
  55. Math

    A green paint is created by mixing 3 parts of yellow with every 5 parts of blue. How many gallons of yellow paint are needed to make 44 gal of this green paint?

    asked on November 2, 2017
  56. Algebra

    A rectangular playground is to be fenced off and divided in two by another fence parallel to one side of the playground. 440 feet of fencing is used. Find the dimensions of the playground that maximize the total enclosed area. Remember to reduce any

    asked on February 28, 2016
  57. Math 141

    Three machines turn out all the products in a factory, with the first machine producing 20% of the products, the second machine 15%, and the third machine 65%. The first machine produces defective products 17% of the time, the second machine 8% of the time

    asked on November 11, 2015
  58. chemistry

    A 20.0 mL sample of 0.687 M HBr is titrated with a 0.216 M NaOH solution. The pH after the addition of 10.0 mL of NaOH is __________.

    asked on July 24, 2012
  59. chemistry

    what are the chemical formula for sodium tetrachloroplatinate(II) and tris(ethylenediamine)cobalt(III) bromide

    asked on March 30, 2012
  60. Calc

    A 100 inch piece of wire is divided into 2 pieces and each piece is bent into a square. How should this be done in order of minimize the sum of the areas of the 2 squares? a) express the sum of the areas of the squares in terms of the lengths of x and y of

    asked on November 16, 2010
  61. General Chemistry

    A certain protein was found to have 0.855% zinc by mass. Determine the minimum molecular mass of the protein. How do I go about solving this?

    asked on September 19, 2010
  62. Chemistry

    Suppose 3.50g of zinc bromide is dissolved in 300.mL of a 65.0mM aqueous solution of potassium carbonate. Calculate the final molarity of bromide anion in the solution. You can assume the volume of the solution doesn't change when the zinc bromide is

    asked on December 17, 2018
  63. Math

    If the probability that an identified hurricane will make a direct hit on a certain stretch of beach is 0.04, what is the probability against a direct hit? So if it is against, would I take 1-.04 and that would be the answer? Thanks!

    asked on February 17, 2017
  64. Math

    Let a, b, and c be unit vectors, such that a+b+c=0. Show that the angle between any two of these vectors is 120 degrees. I proved this geometrically, but now my teacher wants a proof using vectors, and I don't know what to do.

    asked on June 7, 2016
  65. language Arts

    In the excerpt from Barrio Boy, what makes Ernesto similar to several of his classmates?

    asked on January 25, 2016
  66. Chemistry

    A particular MP3 encoder can convert 79.0 kilobytes (kb) of music per second from a typical music CD. How many minutes will it take to convert 13.3 megabytes (Mb) of music from a CD?

    asked on January 29, 2014
  67. Science

    What is the radius in nm of the electron orbit of a hydrogen atom for n=3? What is the radius in nm of the electron orbit of a hydrogen atom for n=4?

    asked on January 14, 2014
  68. calculus

    Using 4x^2 - 9y^2 = 36 Find y by implicit differentiation and then solve the equation explicitly for y and differentiate to get y' in terms of x.

    asked on April 29, 2013
  69. Chemistry

    Which of the following pairs of compounds will give a precipitate in a diluted solution? Question 4 options: A) Cu(NO3)2 and Na2CO3 B) KNO3 and NaCl C) MgCl2 and Ba(NO3)2 D) NH4Cl and Al2(SO4)3

    asked on May 10, 2012
  70. Trig

    prove(sinx/cosx+1)+(cosx-1/sinx)=0 Please help asap!!!!! PLEASE

    asked on March 3, 2012
  71. chemistry

    Rank these species by their ability to act as an oxidizing agent. Na^+ I2 Cr^3+ F2 Put best oxidizing agent first and continue to have best reducing agent last.

    asked on February 29, 2012
  72. geometry

    in an equilateral triangle RST, R has coordinates (0.0)and T has coordinate of (2a,0).Find the coordinates of S in terms of a.

    asked on July 3, 2011
  73. Chemistry

    A sample of air contains 78.8% nitrogen, 20.94% oxygen, 0.05% carbon dioxide, and 0.930% argon by volume. How many molecules of each gas are present in 1.00 L of the sample at 35 degrees C and 1.00 atm?

    asked on July 14, 2010
  74. chem

    classify each of the following as a lewis acid or base: Cl- BeCl2 B(CH3)3 P(Ch3)3 Cl- is an acid right? i'm not sure i understand this concept very well. :[ and i tried looking at my notes already.

    asked on March 28, 2010
  75. College Chemistry

    Calculate the ratio of NaF to HF required to create a buffer with pH=3.95. Also, can you please explain in a nutshell the whole concept of buffers? Thanks!

    asked on March 23, 2010
  76. Calculus

    If the integral from a to b of f(x)dx=a+2b then integral from a to b of (f(x)+3)dx= ? The answer: 5b-2a How do I get to that answer??

    asked on January 11, 2010
  77. literature

    In the merchant of venice act 3 scene 5, Antonio quips that the devil can cite scripture for his own purpose (I, iii, l.95). How does the scriptural debate between Launcelot and Jessica serve each character’s purpose? This debate has the potential to

    asked on October 5, 2016
  78. literature

    In the merchant of venice act 3 scene 4, 1. What does Portia tell Lorenzo that she and Nerissa will do? What is their actual plan? 2. 1. How is Portia equipped to portray a man?

    asked on October 4, 2016
  79. literature

    In the Merchant of Venice, What is Shylock’s initial reaction to Launcelot’s leaving his service? I googled it many times, but I couldn't find the answer! Thanks!

    asked on September 22, 2016
  80. Math--Parametric Equations

    A hockey puck of diameter 3 inches is spinning around its center at a speed of 3 counterclockwise rotations per second. The center of the puck is traveling at a speed of 24 inches per second at an angle of 45 degrees to the positive x-axis. (a) At time

    asked on April 15, 2016
  81. Statistics

    To plan the budget for next year a college needs to estimate what impact current economic downturn might have on student requests for financial aid. Historically, this college has provided aid to 35% of its students. Officials look at a random sample of

    asked on November 11, 2013
  82. statistics

    In a certain region, the mean annual salary for plumbers is $51,000. Let x be a random variable that represents a plumber's salary. Assume the standard deviation is $1300. If a random sample of 100 plumbers is selected, what is the probability that the

    asked on February 25, 2013
  83. chemistry

    If 25.0mL of 0.56 M H2SO4 is diluted to a volume of 125 mL, what is the molarity of the resulting solution?

    asked on October 28, 2012
  84. Chemistry

    Calculate the [H+] of a solution obtained by mixing 1 L of hydrochloric acid 1.0 M with 1 litre of sodium hydroxide 0.990 M.

    asked on May 11, 2012
  85. Probability

    If you are dealt 3 cards from a shuffled deck of 52 cards, find the probability that all 3 cards are picture cards.

    asked on May 7, 2012
  86. physics

    Two children, each with mass m = 11.0 kg, sit on opposite ends of a narrow board with length L = 4.5 m, width W = 0.30 m, and mass M = 9.4 kg. The board is pivoted at its center and is free to rotate in a horizontal circle without friction. What is the

    asked on March 16, 2012
  87. chemistry

    A solution of NaOH(aq) contains 6.2 g of NaOH(s) per 100.0 mL of solution. Calculate the pH and the pOH of the solution at 25 °C.

    asked on January 22, 2012
  88. geometry

    In rectangle ABCD, if the coordinates of A are (0, 0) and the coordinates of C are (r, s), what are the coordinates of B.

    asked on July 5, 2011
  89. Math

    The nominal rate of interest is 8% and the rate of inflation is 5%. A single deposit is invested for 10 years. Let: A= value of the investment at the end of 10 years measured in "constant dollars," i.e. in dollars valued at time 0. B= value of the

    asked on May 11, 2011
  90. physics

    A 120 N child is in a swing that is attached to ropes 2.20 m long. Find the gravitational potential energy of the child-Earth system relative to the child's lowest position at the following times. (a) when the ropes are horizontal (b) when the ropes make a

    asked on October 18, 2010
  91. Geometry

    Glenda wants to glue glitter over a piece of felt shaped like a parallelogram with a height of 36 in. and a base of 46 in. If the glitter costs $1.20 per ft2 to cover the felt, how much will it cost to cover the felt? A) $55.20 B) $1987.2 C) $165.60 D)

    asked on September 15, 2010
  92. Math

    What do you get when you cross a porcupine with a gopher?

    asked on April 15, 2008
  93. Calculus help

    You are going to make many cylindrical cans. The cans will hold different volumes. But you'd like them all to be such that the amount of sheet metal used for the cans is as small as possible, subject to the can holding the specific volume. How do you

    asked on March 21, 2017
  94. literature

    In the merchant of venice, Why do you think there is no Biblical imagery, only mythological imagery, in this scene? (act 2 scene 1) Thanks!

    asked on September 20, 2016
  95. literature

    In the merchant of venice act 2 scene 1: Look at the language he uses in ll.1-12 and 22-38. How does the imagery in his speech reflect the Elizabethan perception of Moors? What the heck does that mean? What is Moors?

    asked on September 20, 2016
  96. precalc(LOGS) CONFUSED!

    How do I rewrite without logarithms?? 2. log x= log a - 4 log b 3. ln t= 3/2 ln a - ln p 4. log y = 3 log x + log 17

    asked on November 11, 2015
  97. math

    A prize of $100, $200, $500, or $1000 will be randomly awarded to a game show contestant, with the probabilities of winning each prize shown in the table below. What is the expected value of the prize that will be awarded?

    asked on October 21, 2015
  98. Chemistry

    Gaseous ethane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 16.2 g of ethane is mixed with 19. g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Round

    asked on April 10, 2015
  99. Chemistry

    An office heater puts out 2070 Btus (British thermal units) of energy in the form of heat per hour. Given that 1 Btu = 1.055 kJ, how many megajoules of energy in the form of heat can be produced per year (365 days) by the heater (assume continuous

    asked on February 1, 2014
  100. Statistics

    The relationship between the number of games won during one season by a minor league baseball team and the average attendance at their home games is analyzed. A regression analysis to predict the average attendance from the number of games won gives the

    asked on May 25, 2013


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