Popular questions and responses by Jane
  1. Statistics

    The lengths of pregnancies are normally distributed with a mean of 273 days and a standard deviation of 20 days. If 64 women are randomly selected, find the probability that they have a mean pregnancy between 273 days and 275 days.

    asked on February 10, 2013
  2. chemistry

    One step in the isolation of pure rhodium metal (Rh) is the precipitation of rhodium(III) hydroxide from a solution containing rhodium(III) sulfate According to the following balanced chemical equation: Rh2(SO4)3(aq)+ 6NaOH(aq)→ 2Rh(OH)3(s)+ 3Na2SO4(aq)

    asked on March 14, 2013
  3. Physics

    A current of 60 mA passes through a loudspeaker of resistance 6 Ω. What is the potential difference across the resistance of the loudspeaker? 36.0 V 10.0 V 0.36 V 0.10 V Answer B seems like it would be the obvious answer..

    asked on October 22, 2012
  4. physics

    The energy given off by 300 grams of an alloy as it cools through 50°C raises the temperature of 300 grams of water from 30°C to 40°C. The specific heat of the alloy (in cal/g C ) is: i know Q=CpM(delta T) but what is what?

    asked on June 22, 2009
  5. Math

    Peter has 1200 yards of fencing to enclose a rectangular area. Find the dimensions of the rectangle that maximize the enclosed area?

    asked on December 4, 2012
  6. trig

    ABC is rightangled triangle. AD is the bisector of angle BAC. Angle DAC=15 degrees. X=CD. Find X. I know the answer is 7.1 but do not know how to do the actual sum. Can you please help AB = 23 CM

    asked on May 5, 2011
  7. physics

    To what temperature must you raise a copper wire, originally at 20.0°C, to double its resistance, neglecting any changes in dimensions? (Does this happen in household wiring under ordinary circumstances?)

    asked on September 13, 2014
  8. physics

    At a picnic, there is a contest in which hoses are used to shoot water at a beach ball from three directions. As a result, three forces act on the ball, F1, F2, and F3 (see drawing). The magitudes of 1 and 2 are F1 = 55.0 newtons and F2 = 95.0 newtons.

    asked on September 12, 2010
  9. Chemistry

    If 1.50 g of H2C2O4 2H2O were heated to drive off the water of hydration, how much anhydrous H2C2O4 would remain? Thank you! Please explain clearly.

    asked on December 19, 2013
  10. Math

    Translate the sentence into an inequality. Ten times the sum of a number and 27 is at least 26.

    asked on October 1, 2017
  11. physics

    what pressure (in atm) would be exerted by 76g of fluorine gas in a 1.5 litre vessel at -37 degrees Celsius?

    asked on April 26, 2013
  12. physics

    A 0.400 kg ball is shot directly upward at initial speed 40.0 m/s. What is its angular momentum about a point 2.0 m horizontal from the launch point, when the ball is a) at maximum height and b) halfway back to the ground? What is the torque on the ball

    asked on June 13, 2009
  13. math

    A local citizen wants to fence a rectangular community garden. The length of the garden should be at least 110 ft, and the distance around should be no more than 380 ft. Write a system of inequalities that models the possible dimensions of the garden.

    asked on December 29, 2011
  14. chemistry

    i already posted this question, but im still confused on it. Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g) -> 2NO2 (g) 2NO2 (g) Initial conc. 0.400 mol 0 mole (no reaction yet) Change -0.3945 mol + 2 x 0.3945

    asked on October 26, 2010
  15. Math

    Two ships leave the same port at the same time. One ship sails on a course of 110 degree at 32 mi/h. The other sails on a course of 230 degree at 40 mi/h. Find the distance between them after 2 hours. Express your answer to the nearest mile.

    asked on March 5, 2018
  16. Math

    A golfer stands 420ft(140 yd) horizontally from the hole and 50ft above the hole. Assuming the ball is hit with an initial speed of 120ft/s, at what angle should it be hit to land in the hole? Assume the path of the ball lies in a plane.

    asked on March 6, 2014
  17. Math

    There are 12 more toy cars than toy trucks in a toy box with a total of 38 toy cars and trucks. How many toy trucks are in the toy box?

    asked on July 5, 2016
  18. History/ Civics

    1.How did the capture of Vicksburg, Mississippi, take advantage of a Confederate weakness? A-The Confederacy had few soldiers and relied on its well-trained generals to win battles. B- The Confederacy had few weapons manufacturers and relied on Vicksburg

    asked on April 29, 2015
  19. Chemistry Class

    Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g) -> 2NO2 (g)

    asked on October 25, 2010
  20. math

    A cyclist travels for 60km at x km/h and 180km at y km/h and takes 10 hours altogether for the journey. If the speed are interchange, the journey takes 8.6 (8 whole number 2 over 3) hours. Find x and y.

    asked on November 16, 2015

    paid two months rent deposit and one month advance, P40,500

    asked on August 23, 2014
  22. Maths

    Andrew arranged the number 1, 2, 3, ...11, 12 into six pairs so that the sum ofany two numbers in a pair is prime and no two of these primes are equal. find the primes and the pairs

    asked on February 3, 2010
  23. Math

    A surveyor sights two signs and the angle between the two lines of sight measures 55. If the first and the second signs are 70 m and 50 m away,respectively,from the surveyor, find the distance between the two signs .Express your answer to the nearest

    asked on March 5, 2018
  24. math

    Find p such that px^2-12x+4=0 has only one solution. Thank you!!!

    asked on April 14, 2016
  25. physics

    A truck is pulling a car. FT is the magnitude of the force that the truck exerts on the car FC is the magnitude of the force that the car exerts on the truck Consider the following scenarios independently. 1)The truck is driving with a constant velocity,

    asked on February 13, 2014
  26. Chemistry

    For the cell diagram Pt(s)|H2(g)|H+(aq)||Cu2+(aq)|Cu(s) Write a balanced equation for the half-reaction at the cathode. The cathode is the site of reduction so copper gets reduced. So wouldn't the answer be: Cu2+(aq) -> Cu(s) + 2e-?

    asked on June 11, 2013
  27. Physics

    A circular plate of radius 0.5 m is placed perpendicular to the direction of the magnetic field of 0.5 Tesla. What is the change of flux in the plate if it rotates and its plane becomes parallel to the direction of the magnetic field?

    asked on May 17, 2013
  28. 8need a function rh grade math

    a 154 lb person burns 420 calories per hr riding an exercise bike at 15 mph. Need a function rule to represent the total calories burned over time.

    asked on May 14, 2013
  29. biology

    Which of the following organs remove nitrogenous waste from the body? a. Liver b. Large Intestine c. Kidneys d. Gall Bladder

    asked on January 26, 2017
  30. chemistry

    suppose 250 mL of a .433 M solution of CuCl2 is electrolyzed. how long will a current of 75A have to run in order to reduce the concentration of Cu2+ to .167M? What mass of Cu will be deposited on the cathode during this time?

    asked on June 18, 2012
  31. Math

    A copy center offers its customers two different pricing plans for black and white photocopies of 8.5 in. by 11 in. pages. Customers can either pay $0.08 per page or pay $7.50 for a discount card that lowers the cost to $0.05 per page. Which equation can

    asked on January 5, 2012
  32. Algebra

    Classrooms on one side of the drama building are all numbered with consecutive even integers. If the first room, the room with the smallest classroom number, on this side of the building is numbered x, write an expression in x for the sum of the first five

    asked on September 1, 2017
  33. Alg 1

    Diana is driving 182 miles to Orlando for a math convention. She has already driven x miles of th trip. If Diana drives below 70 miles per hour for the remainder of th trip, which inequality best represents the amount of time in hours, t, that is will take

    asked on April 29, 2013
  34. alg 1

    Find the percent error in calculating the volume of the prism. V=(bw)(h) v=11 x 8 (7) V=616 my choices were: 19% 10% 119% 83% I'm not sure what it means to find the percent error. Please explain. Thanks.

    asked on April 16, 2013
  35. Alg 1

    Simplifying Radicals A gardener is mowing a 20-yd-by-40 yd rectangular pasture using a diagonal pattern. He mows from one corner of the pasture to the cxorner diagonally opposite. What is the length of this pass with the mower? Give your answer in

    asked on April 2, 2013
  36. Math

    The table shows the height of an elevator above ground level after a certain amount of time. Let y stand for the height of the elevator in feet and let x stand for the time in seconds. Which equation models the data below? Time (s) Height (ft) 10 235 20

    asked on January 5, 2012
  37. math

    Please show me how to solve: At the local ballpark, the team charges $5 for each ticket and expects to make $1,300 in concessions. The team must pay its players $1,800 and pay all other workers $1,500. Each fan gets a free bat that costs the team $3 per

    asked on December 29, 2011
  38. chemistry

    A certain first order reaction has a rate constant of 5.68 x 10–3 s–1 at 139°C and a rate constant of 8.99 x 10–1 s–1 at a temperature of 215°C. Ea = 111 kJ mol– q1) What is the value of the rate constant at 275°C? q2) At what temperature does

    asked on June 2, 2016
  39. Data management

    1)SOLVE: a) 2nP3 = 2(nP4) b)6(n+1P2) = 3nP2 2) If (nC12 = (nC8), find (nC17) and (22Cn) 3)simplify. a) n(squared) (n-2)! - n(n-2)! / n! b) (nC2) - (nCn-2) 4)If nPr - 506 and (nCr_ = 253, find n and r. 5) If (28C2r)/(24C2r-4) = 225/11, find r.

    asked on October 27, 2011
  40. math

    a garden 7m by 12m will be expanded by planting a border of flowers,the border will be of the same width around the entire garden and has an area of 92m

    asked on June 18, 2016
  41. Alg 1

    A golden rectangle is 32 cm long. The ratio of length to width is (1 + sq rt 5)/2. What is the width of the rectangle in simplest radical form? Please solve and explain. Thanks.

    asked on April 3, 2013
  42. physics

    An airplane flies 200km due west from city A to city B and then 305km in the direction of 33.5 degrees north of west from city B to city C. a.) in straight-line distance, how far is city C from city A? b.) relative to city A,in what direction is city C?

    asked on January 28, 2013
  43. arithmetic

    The initial term of an arithmetic sequence is 5. The eleventh term is 125. what is the common difference of the arithmetic sequence?

    asked on October 25, 2011
  44. math

    You have $47 to spend on music and movie downloads. Each album download costs $7 and each movie download costs $8. Write and graph a linear inequality that represents this situation. Let x represent the number of albums and y the number of movies.

    asked on December 31, 2011
  45. Math

    3/5 of the booksin a class library are englishbooks. The rest are non-english books. If the total number of books in the library is 650, how many non-english books are there?

    asked on September 30, 2018
  46. Math please help quick

    Which of the following are identities? Check all that apply. (Points : 2) sin2x = 1 - cos2x sin2x - cos2x = 1 tan2x = 1 + sec2x cot2x = csc2x - 1 Question 4. 4. Which of the following equations are identities? Check all that apply. (Points : 2) Question 5.

    asked on January 12, 2014
  47. Physics

    A balloon carrying a basket is descendign with a constant acceleration of g/3. the total mass of the basket and contents is mB.you see water below and decide you need to throuw out some mass to allow the basket to rise and not hit the water. how much mass

    asked on October 8, 2012
  48. geometry

    Algebra BD bisects

    asked on September 14, 2012
  49. math

    what is 7-2i in trig form? and if u=3j and v=7i+j what is the dot product of u times v don't get this one because there are no i terms for u thanks

    asked on December 30, 2010
  50. physics

    Find the length of a pendulum that has a frequency of 0.80 Hz?

    asked on November 24, 2010
  51. Math

    In a department store there were a certain number of red tshirts, blue tshirts, and yellow tshirts. 3/7 of the tshirts were red, 1/3 of them were blue, and the rest were yellow. If there were 20 more red tshirts than bake tshirts, how many yellow tshirts

    asked on October 30, 2019
  52. Chemistry

    Use the balanced equation for the reaction of lithium oxide with water: Li2O(s) + H2O(g) --> 2LiOH(s) to determine how many grams of H2O can be removed from the air by 250g of Li2O. Show your step-by-step solution with unit conversions.

    asked on September 26, 2018
  53. math

    The amount of Jen’s monthly phone bill is normally distributed with a mean of $50 and a standard deviation of $10. Find the 25th percentile. A. About $46.30 B. About $43.30 C. About $43.40 D. about $43.20 I came up with $43.26 which its not a choice.

    asked on April 16, 2015
  54. math

    The batting averages of the first three batters in the Eureka College women’s softball team lineup are .310, .301, and .277. If the first three batters are considered as the “lead-off group”, what is the batting average of the group? A. .301 B. .296

    asked on April 15, 2015
  55. Chemistry

    A compound with the molar mass of approximately 142 g/mol has the composition 50.7% C, 9.9% H, and 39.4% N. What is its molecular formula? Element order CxHyNz.

    asked on June 11, 2020
  56. Math

    Given a geometric progression whose common ratio is 2, if the sum of the 6th to 7th terms is 288, determine the sum of the 4th to 15th terms inclusive.

    asked on April 18, 2020
  57. Statistics

    Consider the probability that fewer than 17 out of 145 people will get the flu this winter. Assume the probability that a given person will get he flu this winter is 11%. Approximate the probability using the normal distribution. Round the answer to four

    asked on December 3, 2017
  58. Chemistry

    Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g). C2H4(g) + H2O(g) C2H5OH(g) Kc = 9.0 × 103 [C2H4]eq = 0.015 M [C2H5OH]eq = 1.69 M

    asked on December 2, 2014
  59. Alg 1

    Completing the square: Which of the following is a solution x^2 + 14x + 112 = 0? If necessary round to the nearest hundredth. x= -0.24 x= -4.24 x= 4.24 no solution I worked it and got neither of the answers. I got x= 0.9 and x=-14.9. Where did I go wrong?

    asked on April 14, 2013
  60. medicinal chemistry

    the solubility product of PbSO4 at 298K is 1.6x10^-8 mol^2dm^-6. Calculate the solubility of PbSO4 in 0.10mol dm^-3 sulphuric acid.Thanks!

    asked on May 28, 2012
  61. Chemistry

    Arrange the ions: Cu^2+, Ni^2+, Mg^2+, & Zn^2+ in order of decreasing ability to be reduced... & in order of decreasing ability to be oxidized

    asked on May 20, 2012
  62. Intro to calc

    3 numbers x y and z are to bea randomly chosen between 0 and 1. A What is the probability that X + y + z will be less than 1? B What is the probability that both x+ y

    asked on July 20, 2011
  63. calculus

    find the point on the line 6x+7y-5=0 closest to (2,2)

    asked on April 18, 2011
  64. Chemistry

    How many moles of silver nitrate are needed to produce 6.75 moles of copper nitrate (CU(NO3)2) upon reaction with excess copper by useing this equation: 2AgNO3(Aq) + Cu (s)-->2Ag(s)+Cu(NO3)2 (AQ)

    asked on April 14, 2011
  65. chemistry

    How many moles of carbon monoxide are needed to react completely with 1.75 moles of iron oxide? based on this equation: Fe2O3(s)+3CO(g)--->2Fe(s)+3CO2(g)

    asked on April 11, 2011
  66. calculus

    Find the exact value of: cos(arctan(2) + arctan(3)) Please explain how you got your answer. I have the answer, but I don't know how to get to it.

    asked on February 21, 2009

    find the radius and interval of convergence for the series the series from n=1 to infinity of ((-1)^(n+1)*x^n)/n! I did the ratio test so I had the Lim as n approaches infinity of -x/(n+1), but this is 0, giving no radius, so I think I did something

    asked on March 4, 2008
  68. science

    A piece of zinc is added to 1000cm3 of 0.2mol/dm3 hydrochloric acid. After effervescence had stopped, 28cm3 of the resulting solution required 17cm3 of 0.08mol/dm3 sodium trioxocarbonate(IV) solution for complete neutralization. Calculate the mass of the

    asked on June 19, 2020
  69. chemistry

    reacting species of C8H6NH, potassium hydroxide, aqueous ammonia, and calcium hydroxide

    asked on December 19, 2018
  70. Math

    Paul is 20 years older than joy four years ago; the ratio of their ages was 7:3 find the present age of Paul

    asked on May 20, 2018
  71. Calculus

    A rectangle is bounded by the x-axis and the semicircle y = sqrt(36-x^2). What length and width should the rectangle have so that its area is a maximum? I understand that 2xy = A and that 4x + 2y = P, but I'm not sure how to solve for a variable to plug

    asked on March 2, 2016
  72. Please help me with Trig

    Given cos 67.5° = [√(2+√2)]/2, find tan 67.5° , simplify where needed, and show work. I'm starting to learn this stuff, and I'm so confused where to start. I know they gave me the coordinate X as in cos 67.5° = [√(2+√2)]/2, and I also know that

    asked on January 27, 2016
  73. Chemistry

    A 10.0 gram sample of a mixture of CH4 and C2H4 reacts with oxygen at 25°C and 1 atm to product carbon dioxide gas and liquid water. If the reaction produces 520 kJ of heat, what is the mass percentage of CH4 in the mixture? I am all out of tries on the

    asked on October 27, 2014
  74. physics

    An arrow is aimed horizontally, directly at a target 20.6 meters away. when the arrow is released, it lands 0.095 meters below the target point. a) How long was the arrow in the air? b) How fast was the arrow moving when it left the bow?

    asked on October 3, 2014
  75. Chemistry

    Please help! Calculate the standard change in enthalpy, ΔH°rxn, for the decomposition of calcium carbonate to calcium oxide CaCO3 (s) → CaO (s) + CO2 (g) Given that: ΔH°f CaCO3 (s) = -1206.9 kJ/mol ΔH°f CaO (s) = -635.1 kJ/mol ΔH°f CO2 (g) =

    asked on September 27, 2014
  76. Math

    If A= and B=, find the magnitude and direction angle for -2A +3B Find all specified roots: Cube roots of 8i A parallelogram has sides of length 32.7cm and 20.2cm. If the longer diagonal has a length of 35.1cm, what is the angle opposite this diagonal?

    asked on July 30, 2014
  77. Math

    Pythagorean Theorem A rectanglar box is 9 in. wide, 11 in. tall, and 20 in. long. What is the diameter of the smallest circular opening through which the box will fit? If necessary, round to the nearest tenth of a centimeter.

    asked on April 1, 2013
  78. Thermodynamics

    A cylinder contains one liter of air at room temperature (300 K) and atmospheric pressure (10^5 N/m^2). At one end of the cylinder is a massless piston, whose surface area is 0.01 m^2. Suppose that you push the piston in very suddenly, exerting a force of

    asked on February 23, 2013
  79. Algebra

    The difference between the digits in a two-digit numeral is 3. The units' digit is twice the tens' digit. Find the nuermal.

    asked on October 22, 2012
  80. math

    The length of an open-top box is 4 cm longer than its width. The box was made from a 480-cm^2 rectangular sheet of material with 6cm by 6cm squares cut from each corner. The height of the box is 6cm. Find the dimensions of the box. Please show me in detail

    asked on April 21, 2012
  81. math

    Which value below is a possible solution to the compound inequality 0

    asked on April 12, 2012
  82. Chemistry

    How much energy is needed to convert 90g of water (ice) at -85 degrees C to water (liquid) at 48 degree C?

    asked on March 28, 2012
  83. math

    Simplify the radical expression by rationalizing the denominator: 2(square root)108 / (square root) 180y Please show me how to set up and how to solve

    asked on March 21, 2012
  84. Math

    Please explain to me how to solve: A circular mirror is surrounded by a square metal frame. The radius of the mirror is 5x. The side length of the metal frame is 15x. What is the area of the metal frame? Write your answer in factored form.

    asked on January 26, 2012
  85. math

    An artist is going to sell two sizes of prints at an art fair. The artist will charge $20 for the small print and $45 for a large print. The artist would like to sell twice as many small prints as large prints. The booth the artist is renting for the day

    asked on January 4, 2012
  86. Math

    Describe how to draw a line that passes through the origin and has a slope of 3/5.

    asked on November 9, 2011
  87. chemistry

    4NH3 + 5O2 → 4NO + 6H2O 2NO + O2 → 2NO2 3NO2 + H2O → 2HNO3 + NO In this process, the NO made in the last reaction is recycled back into the second reaction and used as a reactant. In the end, all of the NO produced is recycled back so that when the

    asked on September 29, 2011
  88. macroeconomic theory

    4. If an individual's utility function for coffee (x) and cream (y) is given by U(x, y) = min (x, 5y), write the demand function for coffee .

    asked on December 10, 2010
  89. Physics

    An object is released from rest. How far does it fall during the third second of its fall?

    asked on October 26, 2010
  90. physics

    A loaded dogsled has a mass of 400kg and is being pulled across a horizontal, paced snow surface at a velocity of 4.0m/s (N). Suddenly, the harness separates from the sled. If the coefficient of kinetic friction for the sled on the snow is 0.0500, how far

    asked on October 22, 2010
  91. calculus

    f(x) = cos(x) - (cos(x))^2 for -pi is less than or equal to x is less than or equal to pi 1) x-intercepts? 2) x and y coordinates of all relative maximum points? 3) intervals on which f is increasing? then i have to sketch f, so tips on doing so would be

    asked on February 27, 2009
  92. english

    annagrams aeiifglnhpwystThis is an event that will never happen. However, I suppose it could on any given Saturday Night. Here are your letters, you will have 3 left over. A E I I F G L N H P W Y S T

    asked on December 23, 2008
  93. Chemistry

    An aqueous solution of glucose (C6H12O6), called D5W, is used for intravenous injection. D5W contains 54.30 g of glucose per liter of solution. What is the molar concentration of glucose in D5W?

    asked on June 11, 2020
  94. Chemistry

    How many moles of Mg2+ and NO3− form for each mole of Mg(NO3)2 that dissolves?

    asked on June 11, 2020
  95. Chemistry

    A 25.0 mL sample of 0.100 M propanoic acid (HC3H5O2, Ka = 1.3 ✕ 10-5) is titrated with 0.100 M KOH solution. A) 8.0ml B) 12.5 ml C) 20.0 ml D) 25.0 ml E) 25.1 ml F) 28.0 ml

    asked on April 9, 2020
  96. chemistry

    The active ingredient in some antiperspirants is aluminum chlorohydrate, Al2(OH)5Cl. Analysis of a 2.000-g sample of antiperspirant yields 0.334 g of aluminum. What percent (by mass) of aluminum chlorohydrate is present in the antiperspirant? (Assume that

    asked on December 19, 2018
  97. maths

    i have two piece of ribbon one is 17.5cm longer than the other and 1/3 of one ribbon is the same as 3/4 of the other what is the size of the smaller ribbon

    asked on July 9, 2017
  98. calculus review please help!!

    The velocity of a particle moving along the x-axis is v(t) = t^2 + 2t + 1, with t measured in minutes and v(t) measured in feet per minute. To the nearest foot find the total distance traveled by the particle from t = 0 to t = 2 minutes.

    asked on April 27, 2017
  99. Science

    I answered the questions, but I don't know if my choices are right. 1) Which of the following is an acidic pH? 6 7 8 800 None of the Above Answer: 6 ------------------------------------- 2) Which of the following is directly produced by photosynthesis?

    asked on March 21, 2015
  100. cal

    The demand function for a certain make of replacement cartridges for a water purifier is given by the following equation where p is the unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. p = -0.01x^2 - 0.3x +

    asked on December 2, 2014


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