Most popular questions and responses by jackie
  1. physics

    Two people, one twice as massive as the other, try to play tug of war on a nearly frictionless, level, icy surface. When they begin to tug, they are 12 m apart. They tug by pulling the rope hand over hand, until their hands meet along the rope. How far

    asked on December 8, 2014
  2. math

    At a certain time of day, a pole, 5 meters tall, casts a 3 meter shadow. The shadow of the building beside the pole is 18 meters long. How tall is the building? How long will the shadow of a 45 meter building be?

    asked on March 22, 2016
  3. math

    A culture of bacteria grows exponentially. It doubles in size every 16 hours. How long will it take to triple from its original size?

    asked on January 25, 2013
  4. Math

    A deck from a card game is made up of about 108 cards. Twenty-five of them are red, yellow, blue, and green, and eight are wild cards. Each player is randomly dealt a seven-card hand. Write the final answer as a decimal rounded to six decimal places. 1.)

    asked on April 28, 2015
  5. Math

    The hourly operating cost of an airplane, which seats up to 405 passengers, is estimated to be $5,500. If an airline charges each passenger a fare of $100 per hour of flight, find the hourly profit P it earns operating the airplane as a function of the

    asked on February 9, 2012
  6. AP physics

    Vector A has a magnitude of 8.00 units and makes an angle of 45.0° with the positive x-axis. Vector B also has a magnitude of 8.00 units and is directed along the negative x-axis. Using graphical methods, find (a) the vector sum A + B and (b) the vector

    asked on August 23, 2009
  7. chemistry

    Consider a solution made by mixing 500.0 mL of 0.04182 M Na2HAsO4 with 500.0 mL of 0.03645 M NaOH. Complete the mass balance expressions below for Na and arsenate species in the final solution. There are 4 arsenate species, but I only got three of them. I

    asked on March 23, 2013
  8. geometry

    Suppose BD−→− bisects ∠ABC. If m∠ABD=12x+24 and m∠DBC=20x+16, what is m∠ABC?

    asked on October 9, 2015
  9. American Government

    Name the two factors that give federal courts jurisdiction over a case. Give an example of each.

    asked on January 3, 2017
  10. math

    assume the substance has a half-life of 11 years and the initial amount is 126 grams.How long will it be until only 15 % remains?

    asked on January 25, 2013
  11. Calculus AP

    i wanna KNOW IF im DOING RIGHT. Evaluate the difference quotient for the given function. Simplify your answer. f(x)=x+3/x+1, [f(x)-f(1)]/(x-1) simplify my answer: [(x+3)/(x+1) - (1+3)/(1+1)]/(x-1) = [x+3/x+1 - 4/2] / (x-1) = [2(x+3)-4(x+1)/2(x+1)] / (x-1)

    asked on June 4, 2012
  12. statistics

    A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 440 seconds and a standard deviation of 60 seconds.

    asked on March 1, 2011
  13. prealgebra

    A barrel shaped like a cylinder is laid on its side and rolled up a ramp. The barrel has a circular base that is 0.9m in diameter. If the barrel turns 37 times in being rolled up the ramp, how long is the ramp? Use the value 3.14 for π . Round your answer

    asked on November 8, 2015
  14. chemistry

    Ignoring activities, determine the molar solubility of copper (I) azide (CuN3) in a solution with a pH of 10.83. Ksp (CuN3) = 4.9 × 10–9; Ka (HN3) = 2.2 × 10–5.

    asked on March 21, 2013
  15. Chemistry please help :)

    A 1.10 sample of dry ice is added to a 745 mL flask containing nitrogen gas at a temperature of 25.0 degrees C and a pressure of 735 mm Hg . The dry ice is allowed to sublime (convert from solid to gas) and the mixture is allowed to return to 25.0 degrees

    asked on October 24, 2011
  16. math

    ted Williams made deposits of 500.00 at the end of each year for eight years. the rat is 8% compounded annually. calculate the value of ted's annuity at the end of eight years

    asked on September 23, 2016
  17. Chemistry:Important!!!!!!!

    20.00 mL of a H2SO4 solution with an unknown concentration was titrated to a phenolphthalein endpoint with 39.13 mL of a 0.1061 M NaOH solution. What is the concentration of the H2SO4 solution?

    asked on March 3, 2014
  18. physics

    A novice golfer on the green takes three strokes to sink the ball. The successive displacements of the ball are d1 = 3.98 m to the north, d2 = 2.01 m northeast, and d3 = 1.12 m at 30.0° west of south (see the figure). Starting at the same initial point,

    asked on September 26, 2013
  19. Math

    assume the substance has a half-life of 11 years and the initial amount is 126 grams. How much remains at the end of 8 years?

    asked on January 25, 2013
  20. math

    At the amusement park, you decide to ride the Ferris wheel, which has a maxmum height of 80 meters and a diameter of 40 meters. It takes the wheel seven minutes to make one revolution. If you start your ride at the midline and the ferris wheel rotates

    asked on November 21, 2014
  21. Algebra

    The floor of a rectangular room will be tiled with square tiles that measure 3 inches on each side. The room is 109 inches long and 103 inches wide. How many tiles, including parts of tiles, are needed to complete the job? A. 1,248 tiles B. 1,247 tiles C.

    asked on November 11, 2015
  22. Chemistry

    Consider this equilibrium process at 686°C. CO2(g) + H2(g) CO(g) + H2O(g) The equilibrium concentrations of the reacting species are [CO] = 0.050 M, [H2] = 0.045 M, [CO2] = 0.086 M, and [H2O] = 0.040 M. (a) Calculate Kc for the reaction at 686°C. (b) If

    asked on February 23, 2013
  23. DE Science

    I am thinking A. A scientist claims plants and animals that exhibit reproductive cycles based on the changing seasons are highly affected by climate change. What is the correct justification of the scientist's claims? A) Climate change can cause a timing

    asked on November 14, 2013
  24. quantitative chemistry

    Consider a solution made by mixing 500.0 mL of 0.04182 M Na2HAsO4 with 500.0 mL of 0.03645 M NaOH. Complete the mass balance expressions below for Na and arsenate species in the final solution. There are 4 arsenate species, but I only got three of them. I

    asked on March 22, 2013
  25. english

    John was late to dinner and I was late to the movies. simple complex compound compound-complex

    asked on January 5, 2015
  26. Chemistry

    In 6.20 h a 100 g sample of ag 112 decays to 25 grams. what is the half life of ag 112. I think the answer is 3.10 but I'm not sure. Thanks in advance =)

    asked on June 15, 2011
  27. physics help!

    The earth attracts a large flying bug toward its center with a force of 0.10 Newtons. With what force does the bug attract the earth itself? 1. 1.0 N 2. 0.10 N 3. Trillions of Newtons 4. 10 N 5. We need the mass of the bug. 6. Zero; the earth attracts the

    asked on December 8, 2014
  28. math

    a) 1150 dollars invested at 9% annual interest rate (compounded yearly) or b) 1475 invested at 6% annual interest (compounded yearly) after When would the two investments have equal value?

    asked on January 25, 2013
  29. math

    At the amusement park, you decide to ride the Ferris wheel, which has a maximum height of 50 meters and a diameter of 35 meters. It takes the wheel three minutes to make one revolution. If you start your ride at the midline and the ferris wheel rotates

    asked on November 21, 2014
  30. trig

    A bird at the top of a tree looks down at a field mouse with an angle of depression of 65 degrees. If the field mouse is 30 meters from the base of the tree, find the distance from which the field mouse to the bird's eyes. Round the answer to the nearest

    asked on July 22, 2013
  31. physics

    (a) One of the moons of Jupiter, named Io, has an orbital radius of 4.22 108 m and a period of 1.77 days. Assuming the orbit is circular, calculate the mass of Jupiter. (b) The largest moon of Jupiter, named Ganymede, has an orbital radius of 1.07 109 m

    asked on October 22, 2013
  32. eng9

    The profile of an earthquake survivor would most likely be included in (1 point) a feature article. an editorial article. a hard news article. a letter to the editor.

    asked on January 2, 2015
  33. Chemistry

    Consider the reaction: 3Ba(s)+N2(g)--->Ba3N2(s) 1)How many moles of barium metal react to produce 0.190 mol of barium nitride? 2)How many moles of nitrogen gas react?

    asked on December 14, 2011
  34. Physics

    1) Seagulls are often observed dropping clams and other shellfish from a height to the rocks below, as a mean of opening the shells. If a seagull drops a shell from rest at a height of 14 m, how fast is the shell moving when it hits the rocks?

    asked on October 2, 2017
  35. Physics

    A novice golfer on the green takes three strokes to sink the ball. The successive displacements of the ball are d1 = 3.98 m to the north, d2 = 2.01 m northeast, and d3 = 1.12 m at 30.0° west of south (see the figure). Starting at the same initial point,

    asked on September 25, 2013
  36. algebra

    A reduced fat cookie contains 9g of fat per sereving. In order for food to be termed' reduced fat' it must have at least 25% less fat than the regular item. What can you conclude about how much fat is in a serving of the regular cookie? How much fat does a

    asked on May 20, 2011
  37. history

    Which of the following statements about the Grange and Farmers' Alliance movements is most accurate?

    asked on September 21, 2015
  38. Physics

    A block is at rest on an inclined plane. 63 kg µs = 0.47 èc Find the critical angle, èc, at which the block just begins to slide. Answer in units of ◦

    asked on December 7, 2014
  39. Math

    Six sprinters have qualified for the finals in the 100-meter dash at the NCAA national track meet. In how many ways can the sprinters come in first, second, and third? (Let's assume there are no tires).

    asked on April 23, 2015
  40. Math

    The hourly operating cost of an airplane, which seats up to 405 passengers, is estimated to be $5,500. If an airline charges each passenger a fare of $100 per hour of flight, find the hourly profit P it earns operating the airplane as a function of the

    asked on February 9, 2012
  41. Precal

    Use a calculator to evaluate the expression. arcsin 0.45 arctan 15 arcsin(-0.125) arccos(-1/3)

    asked on March 30, 2011
  42. algebra with pizzzaz worksheet

    does anyone know why do girls like guys who wear shirts with eight buttons? I have tried all of the problems two times each and still cannot make any sense of it. thanks!

    asked on February 3, 2009
  43. Calculus help!

    A ball is shot into the air from a bridge, and its height, y, in feet, above the ground t seconds after it is thrown is given by y=f(t) = −16t2 + 55t + 33. What is the average velocity of the ball during the first second? Round your answer to two decimal

    asked on February 6, 2013
  44. math

    An innovative rural public health program is reducing infant mortality in a certain West African country. Pretend the program in Senegal has been reducing infant mortality at a rate 8.1 % per year. How long will it take for infant mortality to be reduced

    asked on January 25, 2013
  45. Physics

    The acceleration of gravity is 9.8 m/s^2 . What is the magnitude of the total force on a(n) 72 kg driver by the dragster he operates as it accelerates horizontally along a straight line from rest to 61 m/s in 7.8 s? Answer in units of kN

    asked on November 30, 2014
  46. Statistics

    Suppose x is a uniform random variable with c = 40 and d = 50. Find the probability that a randomly selected observation exceeds 46

    asked on March 3, 2011
  47. Geometry

    Guy wires 80 feet long support a 65 foot tall telephone pole. To the nearest degree, what angle will the wires make with the ground?

    asked on March 5, 2012
  48. Science: Chemistry - Enthalpy

    The enthalpy change in the combustion of the hydrocarbon octane is delta H = -5.48 x 10^3 kJ/mol C8H18(l). How much heat, in kilojoules, is liberated per gallon of octane burned? (Density of octane = 0.703 g/mL; 1 gal = 3.785 L.)

    asked on June 8, 2011
  49. chemistry

    Determine the molar solubility (S) of Zn(CN)2 in a solution with a pH = 4.91. Ksp (Zn(CN)2) = 3.0 × 10-16; Ka (HCN) = 6.2 × 10-10.

    asked on March 21, 2013
  50. programming

    how do I write a pseudocode to find and display the largest list of positive numbers entered by the user. The user should indicate that he/she has finished entering numbers by enter a

    asked on August 28, 2011
  51. Physics

    The speed of a projectile when it reaches its maximum height is 0.46 times its speed when it is at half its maximum height. What is the initial projection angle of the projectile?

    asked on October 18, 2009
  52. business math

    If the interest rate is 3% and a total of $4,370.91 will be paid to you at the end of 3 year, what is the present value of that sum.

    asked on June 23, 2013
  53. Physics

    A brass rod 50.0 cm long expands 0.0734 cm when heated. Find the temperature change. Using the equation Change in temp=change in length/original length * coefficient of linear expansion for brass I am getting the following result: .0734 cm/(1.9x10^-5)(50

    asked on July 12, 2015
  54. Chemistry

    What is the pH and pOH of a solution that was made by adding 400mL of water to 350mL of 5.0x10^-3 M NaOH solution?

    asked on May 12, 2011
  55. Physics

    A rock is dropped of the side of a bridge and hits the water below 4s later. a. What was the rock’s velocity when it hit the water? b. What was the rock’s average velocity as it fell? c. What is the height of the bridge above the water?

    asked on April 6, 2010
  56. Chemistry

    How much heat (in kilojoules) is released on reaction of 4.10 g of Al? Reaction: 2Al(s) + 3Cl2(g)--->2AlCl3(s) Delta H= -1408.4 KJ

    asked on February 16, 2010
  57. chemistry

    calculate the volume of Nitrogen gas generated at 21 degree celcius and 823 mmHg by the decomposition of 60.0 grams of sodium nitrate?

    asked on July 30, 2019
  58. living environment

    WHY IS THE DIFFERENCE BETWEEN PHOTOSYNTHESIS AND RESPIRATION DECSCRIBED AS A CYCLE? chemically, they are reverse processes: photosynthesis makes organic molecules and oxygen water from carbon dioxide and water. Respiration takes in oxygen and then "burns"

    asked on January 11, 2007
  59. Math

    A certain country taxes the first $20,000 of an individual's income at a rate of 15%, and all income over $20,000 is taxed at 20%. a. Al makes $16,000. Betty makes $36,000. How much is each taxed? b. Write a piecewise function T that specifies the total

    asked on January 28, 2014
  60. Math 208

    nico is saving money for his college education. He invests some money at 6%, and $1400 less that that amount at 5%. The investments produced a total of $172 interest in 1 yr. how much did he invest at each rate?

    asked on May 20, 2013
  61. physics

    A jet of water squirts out horizontally from a hole near the bottom of the tank, as seen in the figure below. Assume that y = 1.19 m and x = 0.544 m. What is the speed of the water coming out of the hole? The hole has a diameter of 3.06 mm. What is the

    asked on March 5, 2012
  62. Shirley English 3 rd grad

    My daughter is working on Fragments and Correcting Run ON Sentences by SCV, SCS, and SS and she did not bring home her book. I have no idea what SCV and SCS and SS means! Can you please help?

    asked on November 10, 2011
  63. Calculus and Vectors

    Show a graphical method of approximating the instantaneous rate of change at x = 3 for the function ƒ(x) = -x2 + 4x + 1 using secants. Show two graphical approximations. I had the same question but instructed to find it using a numerical method. No

    asked on July 15, 2019
  64. Calculus and Vectors

    The magnetic force (Vector FM)on a particle in a magnetic field is found by Vector FM = Vector I × Vector B, Vector I is the charge multiplied by the velocity of a charged particle and Vector B the strength of the magnetic field, in Tesla (T). An electron

    asked on July 3, 2019
  65. Math

    A kite is 32m above from the ground. The angle the kite string makes with the ground is 39°. How long is the kite string, to the nearest metre?

    asked on April 29, 2013
  66. Chemistry

    A concentration cell consists of two Al/Al+3 electrodes. The electrolyte in compartment A is 0.05M Al(NO3)3 and in compartment B is 1.25 M Al(NO3)3. What is the voltage of the cell at 25 degrees Celcius?

    asked on July 20, 2012
  67. Pre-Algebra

    Your baseball team has won 6 games and lost 4 games. If the team does not lose any more games, how many games must the team win to have a win: loss ratio of 2:1.

    asked on February 24, 2014
  68. art

    Analyse a work of art for example Jacob Lawrence "GOING HOME" to describe how he used both elements of art and principles of design to create a strong composition.

    asked on March 19, 2013
  69. economics

    Assume that the equation for demand for bread at a small bakery is Qd = 60 - 10Pb + 3Y, where Qd is the quantity of bread demanded in loaves, Pb is the price of bread in dollars per loaf, and Y is the average income in the town in thousands of dollars.

    asked on September 18, 2012
  70. History

    A late-nineteenth-century Republican would have been more likely than a late-nineteenth-century Democrat to support? states' rights. reduced federal activity. reform legislation. lowered expenditures. help???

    asked on September 21, 2015
  71. Algebra

    Suppose that the annual interest rate on your checking account is 7.5 percent compounded continuously. In order to have $ 6300 in 7 years, how much should you deposit now? Assume, that the current balance is $ 0.

    asked on January 25, 2013
  72. Personal Finance

    Blake Williams has done some research and has discovered that economists believe interest rates will rise significantly over the next two years. Blake believes that this will lead to fewer homes being sold and fewer jobs in the banking and mortgage

    asked on April 21, 2015
  73. chemistry... confusing!

    a scuba diver breathing normal air descend to 100 m of depth, where the toal pressure is 11 atm. What is the partial pressure of oxygen that the diver experiences at this depth? I know that at 100m that a diver would have to breathe Heliox, meaning that

    asked on March 29, 2007
  74. Chemistry

    If your body develops a charge of -19 (microcoulombs), how many excess electrons has it acquired? What is their collective mass? Please explain how to do this

    asked on September 7, 2011
  75. life orientation

    Factors of water that cause contemporary social? issues?

    asked on September 3, 2014
  76. Algebra

    Bit (a lot) of trouble solving this: The landing for the steps leading up to a county courthouse is shaped like a trapezoid. The area of the landing is 1500 square feet. The shorter base of the trapezoid is 15 feet longer than the height. The longer base

    asked on January 31, 2018
  77. Physics

    A ball of mass m(1) = 0.250 kg and initial v(1) = 5.00 m/s collides head-on with a ball of mass m(2) = 0.800 kg that is initially at rest. What are the velocities of the balls after the collision if they stick together?

    asked on January 11, 2013
  78. Physics

    A rocket is fired vertically with an upward acceleration of 30 m/s2. After 20 s, the engine shuts off and the rocket then continues rising (while in free-fall). The rocket eventually stops rising and then falls back to the ground. (a) What is the highest

    asked on September 13, 2010
  79. pre-cal

    A small ferris wheel: A student is riding a 20-m-diameter ferris wheel that is making three revolutions per minute. If there are eight equally spaced seats on the Ferris wheel, then what is the length of the arc between two adjacent seats?

    asked on December 3, 2015
  80. Math/Trig

    An airplane leaves an airport and flies due west 150 miles and then 170 miles in the direction 210°50'. Assuming the Earth is flat, how far is the plane from the airport at this time (to the nearest mile)

    asked on September 27, 2012
  81. Physics

    A rocket initially at rest accelerates at a rate of 80 m/s^2 for 0.74 min. What is its speed at the end of this time? Answer in units of m/s. Plz help and explain

    asked on October 4, 2016
  82. History

    Which author's book on the link between naval might and international power influenced leading statesmen both in the United States and abroad? A) Chester Nimitz B) Oliver Hazard Perry C) Alfred Thayer Mahan D) Josiah Strong

    asked on September 21, 2015
  83. Statistics

    Consumption of alcoholic beverages by young women of drinking age has been increasing in the United Kingdom, the United States, and Europe (The Wall Street Journal, February 15, 2006). Data (annual consumption in liters) consistent with the findings

    asked on December 16, 2014
  84. Calculus and Vectors

    Find the derivative of the following functions using [f(x+h) – f(x)]/h LIM h-0 ƒ(x) = x^2 + 5^x ƒ(x)= 1/2^x Show all your steps. I've been stuck on this question for a while,I understand how to do just the 5^x but not with the x^2 also. Any help

    asked on July 18, 2019
  85. Chem 130

    When calcium carbonate is heated strongly, carbon dioxide gas is released. CaCO3(s) CaO(s) + CO2(g) What volume of CO2(g), measured at STP, is produced if 14.1 g of CaCO3(s) is heated?

    asked on May 5, 2014
  86. Math

    Experience shows that a ski lodge will be full ( 156 guests) if there is a heavy snow fall in December, while only partially full ( 57 guests) with a light snow fall. What is the expected number of guests if the probability for a heavy snow fall is .40? If

    asked on January 18, 2010
  87. Geometry

    One endpoint of a line segment is (8,-1). The point (5,-2) is one-third of the way from that endpoint to the other endpoint. Find the other endpoint.

    asked on October 1, 2011
  88. Calculus and Vectors

    Determine the value of k so that the line with parametric equations x = 2 + 3t, y = -2 + 5t, z = kt is parallel to the plane with equation 4x + 3y – 3z -12 = 0. I got the cross product of (2,-2,0) and (4,3,-3) which is (6,6,14), but that's not adding up

    asked on July 9, 2019
  89. Chemistry

    The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 7.79-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing agent so that all the

    asked on April 23, 2017
  90. Physics

    A figure skater is spinning with an initial angular speed of 6.9rad/s. She then pulls her arms in, reducing her moment of inertia to 0.38 times its original value. What is her angular speed after pulling in her arms?

    asked on March 8, 2012
  91. Chemistry

    How many grams of I2 are present in a solution if 39.85mL of 0.160M Na2S2O3 solution is needed to titrate the I2 Solution

    asked on March 14, 2014
  92. Precalculus

    You have a total of 820 feet of fencing to enclose a large retangular larea and divide it into four smaller pens of the same dimensions. The fencing used to divide the large pen must be parallel to the same side of the large rectangle. Maximize the total

    asked on June 19, 2012
  93. Math

    The annual precipitation for one city is normally distributed with a mean of 329 inches and a standard deviation of 2.6 inches. Find the probability that a randomly selected year will have more than 323.8 inches of rain. Express the probability as a

    asked on September 20, 2015
  94. geometry

    Find the point that is one-fourth of the way from (2,4) to (10,8).

    asked on October 1, 2011
  95. math

    Chris eats 3 slices of a pizza that is cut into 8 equal slices. What percentage of the pizza does he eat?

    asked on March 1, 2011
  96. personal finance

    Which of the following is a true statement? A. The dividends-earnings ratio is a key factor that serious investors use to evaluate stock investments. B. The price-earnings ratio for a corporation must be studied for one period only. C. The price-earnings

    asked on April 23, 2015
  97. HCA

    a 700- to 1,050-word paper that includes the following: • Describe the principles of verbal and nonverbal communication. • Explain which three principles you think are critical for effective communication. • Include at least one personal experience

    asked on October 9, 2012
  98. algebra

    Jeremy is building a deck for the community center. The deck is shaped as rectangle. The width of the deck is 29ft. The perimeter of the deck is to be at least 134ft. Write an inequality that represents all possible values of the length of the deck. Find

    asked on September 9, 2012
  99. math

    A supplier provides parts to a manufacturing company that demands JIT deliveries. At the present time it takes 6 hours to make a round-trip between the supplier's warehouse and the customer, including loading, travel and unloading time. The lot size is 12

    asked on November 30, 2010
  100. chemistry

    Does the application of heat to a substance always produce a chemical change? And give examples to support your answer.can someone help me?

    asked on May 3, 2010


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