Most popular questions and responses by em
  1. Social studies, help

    How did advancements during the Gupta period transform mathematics? A. They invented algebra.**** B. They created the concepts of square numbers and square roots. C. They developed a decimal system with a numeral for zero. D. They made progress in

    asked on November 8, 2018
  2. Math

    Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line. y = 8 sin x, y = 8 cos x, 0 ≤ x ≤ π/4; about y = −1

    asked on January 24, 2013
  3. English

    Restate the theme you selected in the previous question. Support the theme with two details from "Anna's Secret Wish". In the previous question I chose A which is "Each person sees beauty in a different way." I'm having trouble supporting the theme with

    asked on November 13, 2018
  4. Science

    1. Which of the following explains why sunlight is important to the aquatic ecosystems? A. Sunlight provides a source of heat and energy to increase water temperatures. B. Sunlight keeps harmful bacteria from taking over aquatic ecosystems. C. Sunlight

    asked on March 3, 2016
  5. math

    Hi I am trying to help my 4th grade daughter with homework and I am stuck with this question. Please help and explain how you got the answer. Thanks Jill's fish weighs 8 times as much as her parakeet. Together, the pets weigh 63 ounces together. How much

    asked on October 17, 2012
  6. Chemistry

    A compound contains only nitrogen and hydrogen and is 87.4% nitrogen by mass. A gaseous sample of the compound has a density of 0.977 g/L at 680. torr and 84.1°C. What is the molecular formula of the compound?

    asked on November 2, 2010
  7. Math!

    Describe how you would estimate the square root of a number that is not a perfect square without using a calculator. Can someone please explain? I need some help.

    asked on March 2, 2016
  8. stoichiometry

    When Ba(NO3)2 and K2CrO4 (sorry, i don't know how to do subscripts, but all the numbers should be subscripts!) react in aqueous solution, the yellow solid BaCrO4 is formed. Calculate the mass of BaCrO4 that forms when 3.50 x 10^(-3) mol of solid Ba(NO3)2

    asked on June 5, 2008
  9. Pre Calc

    Find the work done by a force F of 30 pounds acting in the direction (2,3) in moving an object 3 feet from (0,0) to the point in the first quadrant along the line y = (1/2)x. The answer is 85.38 foot-pounds. I just need to figure out how to get the answer.

    asked on May 25, 2011
  10. Physics

    Light from a sodium lamp ( wavelength= 589 nm) illuminates a narrow slit and is observed on a screen 75 cm behind the slit. The dstance between the first and third dark fringes is 7.5 mm. What is the width (in mm) of the slit? Cant seem to get the answer

    asked on March 7, 2010
  11. math

    the flight path of a firework is modelled by the function h(t)=-5(t-5)^2+127

    asked on January 17, 2017
  12. physics

    If you fill a container with air at room temperature (400 K), seal the container, and then heat the container to 500 K, what will the pressure be inside the container? Assume atmospheric pressure equal to 100,000 Pa.

    asked on October 13, 2013
  13. Physics

    Suppose a 300–g kookaburra (a large kingfisher bird) picks up a 84.0–g snake and raises it 2.30 m from the ground to a branch. How much work did the bird do on the snake? How much work did it do to raise its own center of mass to the branch?

    asked on March 15, 2016
  14. Math

    The region bounded by the given curves is rotated about the specified axis. Find the volume V of the resulting solid by any method. y = −x^2 + 14x − 45, y = 0; about the x-axis

    asked on January 21, 2013
  15. physics

    A tennis player places a 55 kg ball machine on a frictionless surface. The machine fires a 0.065 kg tennis ball horizontally with a velocity of 55 m/s toward the north. What is the final velocity of the machine? Enter your answer here: m/s

    asked on May 1, 2011
  16. pre-algebra

    You split $1500 between two savings accounts. Account A pays annual 5% interest and Account B pays 4% annual interest. After one year,you have earned a total of $69.50 in interest. How much money did you invest in each account?

    asked on January 24, 2013
  17. English

    The importance of being earnest play please help me 20. Briefly explain two ways the play is either reflective of the Victorian culture or shows the influence of Restoration comedy. Respond in complete sentences. 21. Identify and explain how symbolism is

    asked on January 31, 2017
  18. Physics

    A uniform chain of total mass m is laid out straight on a frictionless table and held stationary so that one-quarter of its length, L = 1.79 m, is hanging vertically over the edge of the table. The chain is then released. Determine the speed of the chain

    asked on February 19, 2011
  19. math

    If a car is speeding down a road at 40 (mph), how long is the stopping distance compared to the stopping distance if the driver were going at the posted speed limit of 25 ? Express your answer as a multiple of the stopping distance at 25

    asked on September 8, 2011
  20. Calc 2

    Use a graphing utility to graph the polar equations and find the area of the given region. Common interior of r = 12 sin(2θ) and r = 6

    asked on August 15, 2011
  21. math

    Find the number of different ways that an instructor can choose 7 students from a class of 35 students for a field trip.

    asked on August 5, 2019
  22. works cited

    i did my works cited page but my teacher said its partially correct could someone please help me revise it 1888. Wikimedia Commons.English Imperial Octopus. Wikimedia Foundation. Web. “Elisa Greathed: An Account of the Opening of the Indian Mutiny at

    asked on August 2, 2018
  23. physics

    Your town is installing a fountain in the main square. If the water is to rise 20 m above the fountain, how much pressure must the water have as it moves slowly toward the nozzle that sprays it up into the air? Assume atmospheric pressure equal to 100,000

    asked on October 13, 2013
  24. algebra 2

    x^2 - 3x + 5 = 0. solve using quadratic formula. show solution

    asked on January 15, 2014
  25. Physics

    In unit-vector notation, what is the torque about the origin on a particle located at coordinates (0, -4.90 m, 4.04 m) due to (a) force 1 with components F1x = 2.67 N and F1y = F1z = 0, and (b) force 2 with components F2x = 0, F2y = 1.23 N, F2z = 5.41 N?

    asked on November 17, 2011
  26. Physics

    Suppose under the certain conditions, the maximum force of friction that could act on a certain car was 3.35*10^3 N. The mass of the car is 857kg. What is the maximum possible centripetal acceleration of the car going around a bend? I know the equation for

    asked on March 22, 2016
  27. Math

    Heidi has 40 flower arrangemts. Rose arrangements are 4 times as many as tulips how many of each do I have

    asked on November 17, 2014
  28. economics

    Suppose the demand curve for a monopolist is QD = 500 − P, and the marginal revenue function is MR = 500 − 2Q. The monopolist has a constant marginal and average total cost of $50 per unit. a.Find the monopolist’s profit-maximizing output and

    asked on October 17, 2013
  29. history

    which features formed natural barriers to expansion and invasion for china? select all that apply.

    asked on October 11, 2019

    1....How much force needed to bring a 3200 lb car from rest to a velocity of 44 m/s in 8 sec.? 2....A ball with a mass of 2 kg move to the right with a speed of 2 m/s. It hits a ball of mass 0.50 kg which is at rest. After collision the second ball moves

    asked on February 18, 2011
  31. Math

    Find the volume generated if the region bounded by y = sin 2x and y = cos x, π/6 ≤ x ≤ π/2 is revolved about the line y = 2. Use the method of washers.

    asked on January 27, 2013
  32. Math

    Find the volume V of the described solid S. The base of S is a circular disk with radius 4r. Parallel cross-sections perpendicular to the base are squares.

    asked on January 21, 2013
  33. Physics

    A tennis ball of mass 58g is thrown 5m into the air before served. Calculate the velocity of the tennis ball just before it is hit with the tennis racket.

    asked on February 14, 2018
  34. Physics

    A billiard ball of mass m = 0.150 kg hits the cushion of a billiard table at an angle of θ1 = 60.0° at a speed of v1 = 2.50 m/s. It bounces off at an angle of θ2 = 47.0° and a speed of v2 = 2.20 m/s. a) What is the magnitude of the change in momentum

    asked on February 27, 2011
  35. physics !!

    A jogger travels a route that has two parts. The first is a displacement A of 2.95 km due south, and the second involves a displacement B that points due east. If the resultant displacement A+B has magnitude 4.13 km, what is the magnitude of B? Im not sure

    asked on September 20, 2010
  36. Chemistry

    The enthalpy of solution of CaCl2 is -82.88kJ. If the specific heat of the solution is 4.184J/g*C and the calorimeter constant can be neglected, what will be the final temperature after 5.36g of CaCl2 is dissolved in 100.0g of H2O at 25.0C? I assume the

    asked on May 20, 2007
  37. Chem

    I'm trying to find the number of protons and neutrons for Carbon-14. The mass number is twelve, but how do you determine the protons and the neutrons, and what are they? Thanks!

    asked on May 28, 2009
  38. electronegativity

    are these the most electronegative elements in order? F O N Cl Br C S I P H

    asked on June 5, 2008
  39. Physics

    A) A partly full paint can has 0.747 U.S. gallons of paint left in it. What is the volume of the paint in cubic meters? I got the answer as 0.00283 cm^3 B) If all the remaining paint is used to coat a wall evenly (wall area = 11.7 m2), how thick is the

    asked on September 23, 2010
  40. Chemistry

    Calculate the volume, in liters, of 5.80×10−3 mol of a gas at 44 ∘C and 0.885 atm .

    asked on November 7, 2018
  41. physics

    A tennis player places a 55 kg ball machine on a frictionless surface. The machine fires a 0.065 kg tennis ball horizontally with a velocity of 55 m/s toward the north. What is the final velocity of the machine? Enter your answer here: m/s

    asked on May 1, 2011
  42. Physics

    If a wheel turns around 6.00 complete rotations, what would the angular displacement of that wheel be in radians?

    asked on March 21, 2016
  43. chemistry

    What volume of 0.140 M HCl is needed to neutralize 2.53g of Mg(OH)_2

    asked on September 29, 2013
  44. math

    For the sequence 3,8,15,24,35.... find a formula for tsubn in terms of n.

    asked on May 22, 2012
  45. math

    A picture is 42 cm by 36 cm. A scale diagram of the picture must fit in a space that is 3 m by 2 m. Write a reasonable scale for the scale diagram.

    asked on January 15, 2016
  46. Math

    in a survey, 15 people said they played basketball, hockey and volleyball. in addition 20 people said they played basketball and hockey. draw a venn diagram to determine how many people in the survey said they played only basketball and hockey.

    asked on September 28, 2016

    1...At what temp. of 0^C steel rod and copper rod have length of 800.1 & 99.9 respectively. At what temp. will the 2 rods have the same length. coeff.of linear expansion Copper-.000017 steel-.000013 2...The length of a brass bar increase from 4.001 into

    asked on March 13, 2011
  48. Chemistry

    What is the total molar concentration of ions in a .200M solution of AlCl3

    asked on September 23, 2010
  49. calculus

    Find a cubic polynomial such as f(x)=ax^3+bx^2+cx+d that has horizontal tangents at the points (-5,4) and (4,-4)

    asked on December 19, 2015
  50. Physics - Please Help

    An m = 6.80-kg clay ball is thrown directly against a perpendicular brick wall at a velocity of 22.0 m/s and shatters into three pieces, which all fly backward, as shown in the figure. The wall exerts a force on the ball of 2670 N for 0.110 s. One piece of

    asked on February 27, 2011
  51. Business

    Describe how Canada's trade has changed throughout the last few years trade (in terms of the surplus and deficits). How has the non-US trade changed? 

    asked on February 13, 2019
  52. Chemistry - Electroplating - URGENT

    "To save on production costs, most automobile bumpers are never coated with more than 200 g of chromium. Determine how much time a standard bumper should be immersed in a chromium vat." This is what I have so far- 96,485 coulombs are required to plate 1

    asked on June 17, 2014
  53. Phyiscs

    A rock is tossed straight up with a velocity of 33.9 m/s. When it returns, it falls into a hole 11.9 m deep. What is the rock's velocity as it hits the bottom of the hole?

    asked on October 4, 2010
  54. Chem

    Why can't we change subscripts when we balance chemical equations? I don't understand why we can change coefficients but not subscripts. Thanks.

    asked on April 19, 2009
  55. Physics

    A car is traveling around a bend at a speed of 12.4 m/s. The bend has a radius of curvature of 66.7 m. Friction is the only force acting towards the center of the circle. If the mass of the car is 862 kg, what is the force of friction required to make the

    asked on March 21, 2016
  56. English:Poetry

    Hi beautiful people :) For English we need to select a poem and write a story based on the poem. The poem I have selected tentatively is William Wordsworth's "There was a Boy". What I was wondering was whether the boy jumped off the cliff, fell off the

    asked on January 24, 2012
  57. Writeteacher

    Hi Writeteacher, would you mind looking at my question below? Thanks Em ps> thanks for all your help so far

    asked on August 9, 2011
  58. Physics

    A rock is tossed straight up with a velocity of 33.9 m/s. When it returns, it falls into a hole 11.9 m deep. What is the rock's velocity as it hits the bottom of the hole?

    asked on October 4, 2010
  59. Physics

    The Place you get your haircut has two nearly parallel mirrors 5.0m apart. As you sit in the chair, yoru head is 2.0 m from the nearer mirror. Looking toward this mirror, you first see your face and then, farther away, the back of your head. ( The mirrors

    asked on March 7, 2010

    In writing and balancing equations using sulfur chemists usually use the empirical formula, S, rather than the molecular formula. Why? I'm not sure how to answer this question.

    asked on March 2, 2016
  61. adv functions urgent

    any math teachers around?

    asked on October 9, 2015
  62. Physics

    A rock is tossed straight up with a velocity of 33.9 m/s. When it returns, it falls into a hole 11.9 m deep. What is the rock's velocity as it hits the bottom of the hole?

    asked on October 4, 2010
  63. English

    What are some good insight questions for A Separate Peace? Some topics can include: Wroter's craft Setting POV

    asked on January 16, 2014
  64. Math

    Let n be any counting number. Using the two questions above as a guide, how many subsets does the set {1,2,3,...,n−1,n} have? Prove it as well. First question:Including itself, how many subsets does the set {1, 2, 3} have? List them. Second Question:

    asked on September 28, 2016
  65. Chem

    Pure gold adopts a face-centered cubic crystal structure. It also has a density of 19.30g/mL. What is the edge length of gold's unit cell? What is the atomic radius of gold? I understand how to do this problem the other way: when you have the unit cell and

    asked on April 15, 2015
  66. math

    After you have worked out at the gym on a stationary bike for 49.0 minutes, the distance gauge indicates that you have traveled 15.7 miles. What was your rate in km/hr?

    asked on August 27, 2012
  67. Physics

    A truck of mass 9212 kg moving at a speed of 73.2 mph has lost its brakes. Fortunately, the driver finds a runaway lane, a gravel-covered incline that uses friction to stop a truck in such a situation; see the figure. In this case, the incline makes an

    asked on February 19, 2011
  68. Chemistry

    a mole of ethanol weighs only 46g; how many molecules does it contain?

    asked on September 19, 2010
  69. English

    I am writing newspaper articles on A Tale of Two Cities, here is my editorial so far: For 18 years my father was secretly and unjustly held in a prison located in Paris, France. I am enraged! The French are robbers who have stolen years away from his life.

    asked on July 4, 2008
  70. weighted averages

    How do you do this? a pineapple drink contains 15% pineapple juice. how much pure pineapple juice should be added to 8 quarts of the drink to obtain a mixture containing 50% pineapple juice? Let X be the amount of pure pineapple that you must add, in

    asked on October 22, 2006
  71. Math

    The region bounded by the given curves is rotated about the specified axis. Find the volume V of the resulting solid by any method. x = (y − 6)^2, x = 1; about y = 5

    asked on January 24, 2013
  72. Chemistry

    Sulfuric acid, H2SO4, is sold as a 36% aqueous solution. What is this concentration in A. Molality B. Molarity C. The Mole Fraction Please and thank you. :)

    asked on October 1, 2012
  73. English - To Kill A Mockingbird

    Hi My earlier question needed some clarification. I'm writing a monologue on a marginilised To Kill A Mockingbird character, I am doing Aunt Alexandra. During my monolouge I made two statements from Aunt Alexandra's pov. The first is that Aunt Alexandra

    asked on June 12, 2011
  74. English

    Would Aunt Alexandra (To Kill a Mockingbird) tell Atticus he needs to choose between being a Finch and being one of them? Would Aunt Alexandra believe that because of the Tom Robinson case the Finches are being though of as badly as the Ewells?

    asked on June 11, 2011
  75. Research

    Can someone help me find more information on George Beers who wrote on Russian Collectivisation? No webmaster contact available for the website I was on. I need to assess the sources reliability and I need the authors credidentials...

    asked on May 26, 2011
  76. Physics

    A 64.5-kg skier moving horizontally at 4.83 m/s encounters a 16.7° incline. a) How far up the incline will the skier move before she momentarily stops, ignoring friction? b) How far up the incline will the skier move if the coefficient of kinetic friction

    asked on February 20, 2011
  77. Chem

    so I have a set of fill in the blanks for symbol, atomic number, mass number, protons, neutrons electrons and charge. Protons: 6 Neutrons: 8 Electrons: 2 I said the atomic number was 6, the mass number was 12, and the charge was +4. The only thing I was

    asked on May 28, 2009
  78. Please check my Algebra

    Determine the maximum possible number of turning points for the graph of the function. f(x) = 8x^3 - 3x^2 + -8x - 22 -I got 2 f(x) = x^7 + 3x^8 -I got 7 g(x) = - x + 2 I got 0 How do I graph f(x) = 4x - x^3 - x^5?

    asked on October 23, 2007
  79. Chemistry

    At a certain temperature, the reaction has Kc = 5 x 108. If a reaction mixture at equilibrium contains 0.26 M of H2 and 0.087 M of Cl2, what is the concentration of HCl?

    asked on March 26, 2016
  80. Math

    How much glas is needed to make a fish tank that is 12 inches long, 8 inches wide, and 9 inches high? The tank is open on top.

    asked on April 29, 2015
  81. Math

    If 2.7m of ribbon costs $4.99 how much does 0.82m of ribbon cost?

    asked on April 22, 2015
  82. Precal

    Find the exact values of tangent and cosecant for angle theta in standard position whose terminal side passes through the point (16,-4)

    asked on November 4, 2012
  83. History

    I need to think of some political, social, and economic issues of the late 19th century. I'm a little confused because some things can go in more than one category, like Labor laws could be all 3, right? Would women's and blacks right to vote be political

    asked on October 4, 2011
  84. English/Film and Media studies

    Hi My assignment is to talk about a documentary that doesn't exist. We had to pretend to create one and one of the things we need to discuss is our shot construction so everything from lighting, location to shot sizes. Then we need to talk about voice

    asked on July 19, 2011
  85. Physics

    An ideal spring has the spring constant k = 395 N/m. Calculate the distance this spring must be stretched from its equilibrium position for 28.9 J of work to be done.

    asked on February 9, 2011
  86. Physics

    If the angular velocity, ω, changes from 7.07 rad/s to 24.2 rad/s over a time of 6.42 s, what is the angular acceleration, α?

    asked on March 21, 2016
  87. Physics

    Your friend Josh tells you that he spends less on gas in the winter than in the summer. He also says that he has to fill up his tank less often in the winter. (a) Which of the following are possible hypotheses that can be formed from Josh’s

    asked on November 6, 2014
  88. math

    Which of the following is a formula for finding the volume of a cube? A. v=e^3, where e= the edge length B. v=(lwh)^3, wherel= length,w=width andh=height C.v=6e^2, where e=the edge length D. v=b*b, where b= the area of the base I picked A since V=s^3 or

    asked on March 30, 2013
  89. Economics

    Hey I've just had a mind blank. What is the term for when a business has outgrown its limits and is starting to perform badly? Thanks for the help

    asked on August 16, 2012
  90. Social Studies

    What is shown on a political map?

    asked on September 28, 2009
  91. Economics

    Given the production function Y=K^.4 N^.6 and A=1 Calculate the level of output when K=4 and N=10

    asked on September 14, 2007
  92. maths - a few questions

    Simplify 3(x-2)^2/x-2 Is the answer 3x^2-10x+10? If not then what is? When p= sqrt2 and q= sqrt6 write pq in the form a(sqrt)b where a and b are integers and b is as small as possible. Multiply out these brackets. Give your answer in the simplest form.

    asked on February 24, 2007
  93. HIM occupany percentage

    A total of 76,006 IP service days of care were given at University Hospital during this year. The bed counts changed from a count of 200 at the beginning of the year to 220 on March 15, and then to 230 on July 1. The count was reduced to 210 on November 15

    asked on February 4, 2018
  94. physics

    Chuck Wagon travel with a constant velocity of 0.98 miles/minute for 9.3 minutes. Chuck then decelerates at -0.11 miles/min/min for 1.8 minutes. Determine the total distance traveled by Chuck Wagon (in miles).

    asked on September 21, 2017
  95. Econ

    If the rate of inflation is 4% per year, how long will it take for prices to double?

    asked on January 24, 2017
  96. math -ans check

    two points on the graph of a linear function are (-3,5) and (-1,4). Determine the equation of the function in slop-point form. ans: m=-1/2 I pick a point (-1,4) y-y1=m(x-x1) y-4=-1/2(x-(-1)) y-4=-1/2(x+1) Thank you ^^

    asked on March 21, 2015
  97. Math

    Bud and frank were playing a game together and together they scored 56 points. Buds score was 8 times higher than franks what are their scores

    asked on November 18, 2014
  98. math

    there are 30 marbles in a bag; 4 blue, 10 red,6 white, 10 yellow. You randomly draw5 marbles without replacement. Find the percent of drawing 2 red marbles and at least 2 white marbles.

    asked on May 23, 2014
  99. Chem

    when 2.31 moles of sulfur hexafluoride are synthesized from te elements, how many grams of fluorine were used PLEASEEEEE HELPPPP MEEE!

    asked on February 4, 2013
  100. Math

    Given that f(x) = 2x^2 - 8x + 9, 0 ≤ x ≤ 3. (a) Find the average value of f. (b) Find c such that f(average) = f(c).

    asked on January 27, 2013


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