joanna

Most popular questions and responses by joanna
  1. General Chemistry

    How many milliliters of 0.5M NaOH must be added to 200 mL of 0.1M NaH2PO4 to make a buffer solution with a pH of 6.9?

    asked on January 31, 2013
  2. Chemistry

    Estimate the value of the equilibrium constant at 500 K for each of the following reactions. 2H2S(g)⇌2H2(g)+S2(g) I have calculate my delta H which is 168.9 kj/mol but I don't know where to go from there

    asked on April 19, 2016
  3. statistics

    A bank loan officer rates applicates for credit. The rating are normally distributed with a mean of 200 and a standard deviation of 50. Find the P60, the score which separates the lower 60% from the top 40%. I get 212.7, using the normal distribution tool

    asked on August 4, 2007
  4. MATH

    In Mrs.Marshall'd classroom, 6/7 of the students play sports. Of the students who play sports, 4/5 also play as instrument. If there are 35 students in her class, how many play sports and an instrument?

    asked on March 3, 2015
  5. math - gr 12

    the social convenor has 12 volunteers to work at a school dance. Each dance requires 2 volunteers at the door, 4 volunteers on the floor, and 6 floaters. Joe and Jim have not volunteered before so the soicial convenor does not want to assign them to work

    asked on February 23, 2009
  6. Univ Physics-resistance

    A hollow cylindrical resistor with inner radius r1 and outer radius r2, and length l, is made of a material whose resistivity is rho. A.Find the resistance for current that flows radially outward. Divide the resistor into concentric cylindrical shells and

    asked on February 9, 2010
  7. physics

    A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 270 N applied to its edge causes the wheel to have an angular acceleration of 0.854 rad/s2. (a)

    asked on April 2, 2016
  8. statistics

    suppose that iq scores have a bell-shaped distribution with a mean of 97 and a standard deviation of 17. using the empirical rule, what percentage of iq scores are greater than 46? please do not round your answer.

    asked on June 24, 2018
  9. Chemistry

    In the reaction,C2H4(g) + 3O2(g) =2H2O(g) + 2CO2(g),what is the complete combustion of 12.5cm3 of ethene

    asked on April 2, 2017
  10. Science

    What happens when 1 Liter of Carbon Tetrachloride is poured into a container of Water?

    asked on September 30, 2012
  11. physics

    1. A closed magnetic circuit of cast steel contains a 6cm long path of cross sectional area 1cm square and a 2cm part of cross sectional area of 0.5cm square. A coil of 200 turns is wound around the 6cm length of the circuit and a current of 0.4ampere

    asked on April 18, 2012
  12. Phys sci

    Which one of the following frequency can set the string into resonant vibration? If a guitar string has a fundamental frequency of 500Hz a)250Hz b)750Hz c)1500Hz d)1750Hz

    asked on December 8, 2009
  13. Maths,science

    Choose the correct option and write 1) air,water, minerals, soil,are_ factors of an ecosystem ( physical, organic,inorganic)

    asked on May 4, 2019
  14. physics

    The large quadriceps muscle in the upper leg terminates at its lower end in a tendon attached to the upper end of the tibia (see figure (a)). The forces on the lower leg when the leg is extended are modeled as in figure (b), where vector T is the force of

    asked on April 2, 2016
  15. Physics

    A 6.5-kg bowling ball thrown with a speed of 5.4 m/!@#$%^&s a stationary 1.75-kg pin. What is the velocity of each object? Assume that the coefficient of restitution is 0.75.

    asked on February 1, 2015
  16. Chemistry

    Compare and contrast the processes of nuclear fission and fusion, showing similarities and differences. Describe which, if any, of these processes is naturally occurring. If so, where?

    asked on May 24, 2013
  17. Calculus

    A rectangular plot of land is to be fenced in using two kinds of fencing. Two opposite sides will use heavy-duty fencing selling for $3 dollars a foot, while the remaining two sides will use standard fencing selling for $2 a foot. The fence is to cost

    asked on April 24, 2019
  18. physics

    A volume of gas v at temperature T1 and pressure P, is enclosed in a sphere. It is connected to another sphere of volume v/2 by tube and stopcock. This second sphere is initially evacuated and the stopcock is closed. If the stopcock is now opened and the

    asked on March 21, 2012
  19. Math

    A 17 foot pipe is cut into three sections. The longest section is 3 times as long as the shortest and the middle sized section is 2 feet longer than the shortest. Find the length of each section to the nearest foot

    asked on August 19, 2013
  20. Math

    assume that oil spilled from a ruptured tanker spreads in a circular pattern whose radius increases at a constant rate of 2 feet per second. how fast is the area of spill increasing when the radius of the spill is 60 feet? Note: you must state and use the

    asked on April 24, 2019
  21. Chemistry

    The rate constant for a certain reaction is = 4.30×10−3 s^-1. If the initial reactant concentration was 0.400 M , what will the concentration be after 19.0 minutes? Rate would be first order therefore I used. A=A initial*e^-kt I keep getting .0030 M but

    asked on January 31, 2010
  22. chemistry

    calculate the mass given element of each of the following compounds a) brimine in 50.0 potassium bromide, KBr b) Chromium in 1.00 kg sodium dichromate Na2Cr2O7

    asked on March 13, 2008
  23. Statistics and Probability

    A box contains 4 red and 5 blue marbles. Michele picks three marbles at random from this box. If Z is a random variable representing the # of blue marbles picked from the box, do the following. a. Express the probability mass function of Z in tabular form.

    asked on January 20, 2018
  24. Calculus

    an experimental farm has 3600 ft. of fencing to create a rectangular area that will be subdivided into 4 equal subregions, what is the largest total area that can be enclosed?

    asked on October 10, 2016
  25. physics

    Question Part Submissions Used A 11.5-kg cylinder rolls without slipping on a rough surface. At an instant when its center of gravity has a speed of 10.9 m/s, determine the following. (a) the translational kinetic energy of its center of gravity J (b) the

    asked on April 2, 2016
  26. Precalculus

    invests 7000 for 1 year part at 5% part at 11% and the remainder at 13% total amount of income from these investments was $774. The amount of money invested at 13% was $1200 more than the amounts invested at 5% and 11% combined find the amount invested at

    asked on November 30, 2012
  27. physics

    an ideal monatomic gas is allow to expand slowly until its pressure is reduced to exactly half its original value. By what factor those the volume changes if the pressure is (1)isothermal (2)adiabatic. Please is the answer suppose to be a calculation or an

    asked on March 8, 2012
  28. MATH

    Show three ways to estimate 3/5 ¡¿ 9 1/2. Identify each method you used.

    asked on March 2, 2015
  29. accounting

    . On June 1st, Green Pea, Inc. purchased $1,200 worth of supplies on account. How does this transaction affect Green Pea's accounts? a. Increase supplies and accounts payable by $1,200 b. Increase supplies and decrease cash by $1,200 c. Increase supplies

    asked on August 25, 2013
  30. physics

    Use conservation of energy to determine the angular speed of the spool shown in the figure below after the 3.00 kg bucket has fallen 4.05 m, starting from rest. The light string attached to the bucket is wrapped around the spool and does not slip as it

    asked on April 2, 2016
  31. Math

    determine the value of k such that g(x)=3x+k intersects the quadratic function f(x)+2x^2-5x+3

    asked on October 12, 2011
  32. math

    I flip a fair coin seven times in a row. What is the probability that I get at most five heads?

    asked on February 4, 2015
  33. Math

    (i don't know if i posted but im just doing it again just in case) A 17 foot pipe is cut into three sections. The longest section is three times as long as the shortest and the middle sized section is two feet longer than the shortest. Find the length of

    asked on August 19, 2013
  34. science

    What is itvbarnoeso unscrambled ?

    asked on December 17, 2012
  35. physics

    A volume of gas v at temperature T1 and pressure P, is enclosed in a sphere. It is connected to another sphere of volume v/2 by tube and stopcock. This second sphere is initially evacuated and the stopcock is closed. If the stopcock is now opened and the

    asked on March 21, 2012
  36. Math, Statistics

    I know its 1 - P(5/128) but I don't think its correct?? I flip a fair coin seven times in a row. What is the probability that I get at most five heads?

    asked on February 4, 2015
  37. math

    I have a bag that contains 10 red marbles, 9 green marbles, and 6 blue marbles. I reach into it and take one marble at random. Keeping that marble, I reach into the bag again and take a second marble at random. a. What is the probability that the first

    asked on February 4, 2015
  38. science

    In Vista and Windows 7, which process allows you to display two documents side by side? A. Click the Windows button, choose Control Panel, and select the Tile Windows Vertically option. B. Right-click the mouse button in a blank area of the taskbar; in the

    asked on August 15, 2012
  39. Physics

    A simple pendulum has mass 1.14 kg and length 0.760 m. (a) What is the period of the pendulum near the surface of Earth? (b) If the same mass is attached to a spring, what spring constant would result in the period of motion found in part (a)?

    asked on February 15, 2015
  40. math

    Let A and B be events such that P(B)=0.28, P(B|A) =0.44 and P(A or B)=0.63, What is P(A)

    asked on February 4, 2015
  41. chemistry

    A sample of sulfer, mass 2.56 g is burned in excess oxygen inside a calorimeter of heat capacity 923JK and insulated by 815g of water. If the sole product of combustion is SO2, what is the expected increase in temperature? I don't need the answer, just the

    asked on November 30, 2010
  42. chem

    when 1.00g of sucrose C12H22O11 was combusted in a calorimeter to give CO1 and H20, the temperature rose from 25.00 to 27.32 C. The calorimeter itself had a heat capacity of 837JC and was submersed in 1500.0g of water. Find the heat of combustion of

    asked on November 30, 2010
  43. Algebra 2

    I need to know how to solve quadratic equations by factoring. Can you so a step by step explanation to this sample problem? 2 x -12x-28

    asked on November 30, 2009
  44. chemistry

    On a hot sunny day.... why is the chrome fender of a white convertable car with its top down cooler to touch, than its dark red plastic seats? Is it because the lighter the color is, the less heat is absorbed? why id an asphalt sidewalk warmer to touch on

    asked on April 5, 2008
  45. science

    In Vista and Windows 7, which process allows you to change the desktop background? A. Click the Start button, choose Control Panel, and select Display Properties. B. Right-click on the desktop; in the menu that appears, select Display Properties. C. Click

    asked on August 15, 2012
  46. physics

    A volume of gas v at temperature T1 and pressure P, is enclosed in a sphere. It is connected to another sphere of volume v/2 by tube and stopcock. This second sphere is initially evacuated and the stopcock is closed. If the stopcock is now opened and the

    asked on March 21, 2012
  47. physics

    vector A has a magnitude of 57 m and points in a direction 20 degrees below the positive x axis. vector B has magnitude of 70 m and points in a direction 57 degrees above the positive x axis. Find the magnitude of the vector D = A-B.

    asked on September 8, 2010
  48. physics

    A curve of radius 20 m is banked so that a 970 kg car traveling at 50 km/h can round it even if the road is so icy that the coefficient of static friction is approximately zero. The acceleration of gravity is 9.81 m/s^2 Find the minimum speed at which a

    asked on November 1, 2012
  49. physics

    i need three different project topic in physics

    asked on April 14, 2012
  50. physics

    A volume of gas v at temperature T1 and pressure P, is enclosed in a sphere. It is connected to another sphere of volume v/2 by tube and stopcock. This second sphere is initially evacuated and the stopcock is closed. If the stopcock is now opened and the

    asked on March 21, 2012
  51. physics

    an ideal monatomic gas is allow to expand slowly until its pressure is reduce to exactly half its original volume. By what factor those the volume change if the process is (1)isothermal (2) adiabatic

    asked on March 8, 2012
  52. FRENCH

    COuld you please tell me if Ive translated these French words and phrases right? Est-ce qu(e) - Phrase introducing a question Ne Quitte pas - Wait a minute? Maintenant - Now Il y a des defiles et beaucoup de bals: -There are some parades and many dances Ce

    asked on February 21, 2011
  53. Physics

    The mass of the Moon is 7.35 x 10^22 kg. At some point between Earth and the Moon, the force of Earth's gravitational attraction on an object is cancelled by the Moon's force of gravitational attraction. If the distance between Earth and the Moon (centre

    asked on February 4, 2011
  54. English

    I trying to find out what life was like in England in 1564 on rich and poor people, what jobs, kind of places they lived, social life, how much money to live, what food and drink they had. I have been unable to find a website that gives me this

    asked on February 3, 2009
  55. MATH

    I don't get it. At all. HELP!! ¤Ð-¤Ð 😭 Jenna lives 4 3/10 miles from school. She estimates that she travels 4¡¿2¡¿5, or 40 miles each week. Is her estimate an overestimateor an underestimate? EXPLAIN!!!!

    asked on March 2, 2015
  56. probabilities

    A bag contains 3 green balls. 2 red balls and a white ball. A boy randomly draws balls from the bag one at a time (with replacement) until a red ball appears. Find the probability that he will make at least 3 draws.

    asked on November 20, 2012
  57. physics

    i need three project topics in physics. Help please

    asked on May 12, 2012
  58. physics

    an ideal monatomic gas is allow to expand slowly until its presssure is reduced to exactly half its original value. By what factor does the volume change if the pressure is (1) isothermal (2) adiabatic

    asked on March 8, 2012
  59. Pre-algebra

    Kiron invests $22,700 at 14% interest. About how much interest will he earn in 6 months? a.$19,068 b.$3,178 c.$1,589 d.$530

    asked on April 12, 2011
  60. calculus

    f(x)=x8+7x2+613(x−1)2(x+6)6

    asked on September 27, 2010
  61. Calculus

    The value of y changes by 3 units when x changes by 0.1 unit. About how fast is y changing?

    asked on September 16, 2010
  62. Organic Chemistry

    What are proper techniques to induce crystallization from a saturated solution? (Select all correct answers.) Allowing the solution to cool down. Scratching the outside of the container with a glass rod. Seeding the solution. Adding a solvent that lowers

    asked on April 29, 2010
  63. Physics

    Consider the electric field created by a very long charged line of negative linear charge density -2.50 nC/m. A small positive point charge of 7 mC moves from a distance of 9 cm to a distance of 17 cm. How much work is done by the electric field?

    asked on February 11, 2010
  64. social studies

    why would a store owner spend so much money on decoating their store?

    asked on November 24, 2009
  65. college english

    Please Help Me Revise My Essay: An unknown author once said, “A good teacher is like a candle - it consumes itself to light the way for others.” Of all the teachers I have had throughout my educational history there is only one that stands out the

    asked on June 26, 2009
  66. 9th grade

    I need to write an essay on something I have accomplished using 5 adjectives and 2 inference words. What are some examples of inference words?

    asked on March 18, 2009
  67. data management (gr.12)

    ana finds 11 shirts in his size at a clearence sale. How many different purchases could ana make? the answer is 2047, any idea how to answer this? thanks!!

    asked on February 23, 2009
  68. world histoy

    why did the United States declare war on Germany?

    asked on January 27, 2008
  69. physics

    A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 16.0 m/s. The cliff is h = 25.0 m above a flat horizontal beach, as shown in the figure below. How long after being released does the stone strike the

    asked on February 4, 2016
  70. physics

    A ball is thrown directly downward with an initial speed of 8.95 m/s, from a height of 29.0 m. After what time interval does it strike the ground?

    asked on January 31, 2016
  71. Pre Calc

    Find cos 2A if tan A = 5/12 and

    asked on December 1, 2015
  72. Math

    Tony is making half-pound bags of trail mix for a camping trip with his scout troop. He has 101 /2 pounds of peanuts and 91 /2 pounds of raisins. How many bags of trail mix can he make in all?

    asked on October 22, 2015
  73. ethics

    What are some ethical issues that a warden faces with the correctional officers and inmates

    asked on September 8, 2014
  74. medical records

    how important is having the ability to read medical charts and reports? Why can abbreviations in charts be a cause of concern? How would you ensure that your staff and other health care professionals are proficient in medical abbreviations and terminology?

    asked on September 24, 2012
  75. computer packages

    describe the following in not less than five sentence with examples. (1) rational database (2) schema

    asked on March 16, 2012
  76. algebra

    how do you Write a point-slope equation for the line with the given slope that contains the given point. with m=-3;(-2,-5)

    asked on January 23, 2012
  77. Alegaba 2

    Two sides of a triangles are equal in length. the length of the third side is three meters less than the sum of the lengths of the other two sides. What is the length of the longest side of the trangle if its perimeter is 29 meter?

    asked on September 13, 2011
  78. algbra

    Explain how to find the sum positive eight plus negative ten using game chips, then give the answer.

    asked on September 8, 2011
  79. health projects

    i need ideas how to make a reproductive system of the female? i don't have no clue how to make it

    asked on September 2, 2011
  80. Spanish-7th grade-Please check

    If I just have a picture of la sala and it's neat and tidy and has a television in it, which would be the correct response? 1.Mi familia acaba de limpiar la sala. 2.Mi familia mira la television. 3.Mi familia necesita limpiar la sala. 4.Mi familia limpia

    asked on May 19, 2011
  81. math helpy

    Evaluate: 16^-3/4

    asked on January 13, 2011
  82. Economics

    The Andrews Corporation produced satellite dishes, was purchased by another compay, which was a cable company: The Total Cost function for the New Company is: TC = 1,000 + 16Q – 16Q2, where the demand curve for Satellite Dishes is PS = 400 – QS and

    asked on July 16, 2010
  83. social studies

    what is the difference between vertical and horizontal integration?

    asked on November 24, 2009
  84. math!!! help please?!

    what is the probability of not throwing 7 or doubles for 6 consecutives throws with a pair of dice? help please?!?!!

    asked on March 8, 2009
  85. history

    Why was the Civilian Conservation Corps so effective in bringing work and opportunities to Americans during the Great Depression? Use examples to support your answer.

    asked on January 18, 2019
  86. chemistry

    Moles chemistry? Calculate the mass of solute required to prepare ib the solution 200cm^3 of solution containig 0.50 mol dm ^-3 cl-iond prepared by dissolving cacl2.6h2o in water.

    asked on December 8, 2016
  87. chemistry

    Find the number of moles in 12×10^24 CO2 molecules 1mole is equal to 6.0×10 ^23 ? 12x10^24 Then division of them but the answrr did not match the answer of the book

    asked on December 8, 2016
  88. crime control model

    •How do advocates of the crime control model view plea-bargaining?

    asked on December 9, 2014
  89. juvenile deliquency

    What is a sub-cultural issue that is most proematic in causing juvenile delinquency

    asked on November 19, 2014
  90. criminal justice

    To some, the victim's rights movement is more an exercise in symbolic politics than a substantive program. As a result, some critics argue that many of these programs are really more interested in severe punishment of the defendant than in helping victims

    asked on November 12, 2014
  91. criminal justice

    how each player in the criminal justice system impacts the decision-making process.

    asked on November 1, 2014
  92. math

    Consider the line 9x - 7y =4 What is the slope of a line parallel to this line? What is the slope of a line perpendicular to this line?

    asked on May 8, 2014
  93. Chemistry lab reports online?

    Are there any websites with other students' lab reports with calculations online? I do not want to copy and am completely against plagiarism. I just want to look at others' examples to help in giving me ideas on how to write my own and make sure I have

    asked on April 28, 2014
  94. law

    Why did Congress repeal the mandatory federal sentences for drug offenses in 1970?

    asked on November 22, 2013
  95. math

    the challenge involves in dealing with the owner is to use a 20 meter fencing material to build a pig pen so that the owner will not be buying any additional materials considering also that one side of the pen is the outside wall of his garage? what is the

    asked on September 18, 2013
  96. english literature

    How does The Misfit embody both verses of Matthew 12:35? "A good man from the goodness of his good heart brings forth good things; an evil man from the evilness of his evil heart brings forth evil deeds."

    asked on May 31, 2013
  97. statistics

    1. 35% of North Americans do not think that college education is a contributory factor to economic success. A random sample of seven North Americans is selected

    asked on March 29, 2013
  98. science

    Which Windows feature allows you to personalize your computer system? A. My Pictures C. Default Programs B. Control Panel D. Computer

    asked on August 15, 2012
  99. science

    In Vista and Windows 7, which process allows you to change the desktop background?

    asked on August 15, 2012
  100. algebra

    on average a child grows 2.5 inches per year from age 2 until adolescence. write an equation that shows how to calculate the height h of a child given the number of years y since age 2 if the child is 33 inches tall at at 2?

    asked on January 24, 2012

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