Posts by Richard

Total # Posts: 316

  1. Physics

    If light travels through a medium at a speed of 1.987 x 10^8 m/s, what is the index of refraction of the medium? * 1.33 1.36 1.51 1.53
  2. Chemistry

    Can anyone help me check my classifications of these into metallic, ionic, molecular or covalent network, and if I am wrong tell me why Aluminum - Mettalic Ascorbic acid - ionic Graphite - covalent Paraffin - molecular Palmitic acid - ionic Sodium chloride - covalent Sucrose...
  3. Math - Algebra

    An architect is designing a building in the shape of a rectangular pyramid. The number of windows on each floor forms an arithmetic sequence. There are 76 windows on the 7th floor, 68 on the 8th floor, and 4 on the very last floor Find an explicit formula to show this sequence...
  4. physics

    A copper Calorimeter of mass 150g,was half-filled with water of mass 300g and a temperature of 0°C.5g of ice of mass 0°C was added to the content, later some quantity of steam was passed into the mixture and the temperature rose by 20°C. Calculate the quantity of ...
  5. civil education

  6. History, please check

    B,C,D I got a 100
  7. algebra

    A 12 - ft ladder leans against the side of a house. The bottom of the ladder is 6 ft from the side of the house. How high is the top of the ladder from the ground? If necessary, round your answer to the nearest tenth.
  8. 5th grade math equation

    I have tried everything to help my son and I can't figure it out. I am trying to get an end result of 38 out of the following equation. We have to add parentheses to make it equal 38 any help !!! 3+6*5+4/2-7
  9. Chemistry

    Thanks to Dr. Bob for answering all these questions! I always do poorly on conceptual problems. Consider the following equilibrium system at 25°C and select the true statement below: H2PO4?(aq) + SO42?(aq) ? HSO4?(aq) + HPO42?(aq) ?G°rxn > 0 at 25°C (1) this is ...
  10. calculus

    How would you use series to evaluate the lim(x->0) of (x-arctanx)/x^3? I'm getting stuck, and the answer says it's 1/3 but I don't know how they got there.
  11. calculus

    I got 1+3x+6x^2+10x^3+15x^4... but I was wondering how I would write a series for this.
  12. calculus

    How would you determine the power series of 1/(1-x)^3. I know that the series of 1/(1-x) is x^n, but how would you manipulate it for this scenario?
  13. math

    there are 20 students in mark`s homeroom class. Ten percent of the students in marks homeroom class are also in art class He finds the number of students in his homeroom class who are also in art class like this . Can you tell me the answer of how many error he made.
  14. ed tech HELP PLS

    I would say , A. What you post can hurt or slander others***
  15. math-integrating factor

    dy/dx - y/x = 0 I got 1/x, but I am not sure if this is right or not.
  16. Algebra 2

    There are 41 individuals in a grocery store, of which 18 are female. the total number of individuals who are 30 years old or older is 24 of which 10 are female. If an individual is randomly selected, what is the probability that they are either male or 30 years or older?
  17. Chemistry

    Ammonia (NH3) reacts with oxygen to produce nitric oxide (NO) and water (see balanced equation below). How many grams of oxygen do you need to react with 21.4 g ammonia? __4_NH3 + __5_O2 → __4_NO + _6__H2O
  18. American Government

    yo bro I need the answers imw at behind and need to catch up
  19. Government

    Thanks reed
  20. Maths

  21. physics

    a ball projected vertically upwards from the top of the tower 60 meters high with a velocity of 30 meters per second. what is the maximum height above the ground? how long does it take to reach the ground?
  22. American government

    A A C B Thank me later
  23. American government

    A D C I got a 100
  24. Homeschool

    Haha I love how you can just cheat in home school
  25. chemistry

    pH of 1.0 x 10-8 M RbOH
  26. math

    A flame is ejected vertically upward from the groung at 15m/s.Find the height of the flame after 2.5seconds
  27. chemistry

  28. life orientation

    Clealy describe a recent corruption and fraud cases in the country making headlines in the media
  29. Algebra

    Explain how you can tell the function is not linear by using points on its graph. Make sure to include in your answer the Points you used to determine that the function is not linear.
  30. Maths

    a map with a scale of 1cm to 5km has an area of 405cmsquare. what is the actual area of this map on the ground?
  31. Physics

    A Ball Of Mass 0.25kg Losses Half Of Its Velocity When It Makes A Head On Collision With An Identical Ball Q At Rest.After The Collision,Q Moves off with a speed of 2m/s in the original direction of p.calculate the initial velocity of p.
  32. math

  33. Intro to Chemistry

    A 9.40-L container holds a mixture of two gases at 47 °C. The partial pressures of gas A and gas B, respectively, are 0.344 atm and 0.520 atm. If 0.160 mol of a third gas is added with no change in volume or temperature, what will the total pressure become?

    1. ZG Jewelers purchased fashion bracelets for $38.87. This jewelry store regularly marks up fashion merchandise 52% of the selling price. What is the minimum selling price that ZG Jewelers should charge? 57.20 59.23 80.98 94.94
  35. science

    a 2kg stone is dropped from the top of a 20 buliding (a) at what height does its potential energy energy equal to its kinetic energy?
  36. social studies

    Answer is 18!!!!!
  37. accounting and finance

    premium higher more
  38. math

    There are 40 vehicles in a parking lot. Twenty percent of the vehicles are pickup trucks. How many pickup trucks are in the parking lot?
  39. Physics (Thin Film Interference)

    Sorry I got 91.46 and 274.379. You were supposed to add 1/2 wavelength for the second value but why can't you add 1 whole wavelength especially since destructive interference is 1/2 wavelengths, 3/2 wavelengths, 5/2...etc.?
  40. Physics (Thin Film Interference)

    A layer of transparent plastic (n=1.61) on glass (n=1.52) looks dark when viewed in reflected light whose wavelength is 589 nanometers in vacuum. Find the two smallest possible nonzero values for the thickness of the layer. Answers are 183 nm and 366 but I don't understand...
  41. science

  42. Math

    A child's desk is made so that the dimensions are two-thirds the dimensions of a full-size adult desk. Suppose the top of the full-size desk measures 54 inches long by 36 inches wide. What is the perimeter and area of the topof the child's desk?
  43. English

    Hi! I'm trying to find a lit device for this quote. This quote is from "The Story of An Hour" by Kate Chopin. I'm struggling to find a lit device. So far I've come up with "contrasting diction" but I'm trying to find an even stronger one. ...
  44. tourism,Maths Literacy,Geography &Life Science

    U cn b a social worker,psychologgy an lawyer but the requiriments for this,u mst have a bachelor degree
  45. math help

    3^(n+1)-3^(n-2) Need help simplifying this please.
  46. College Algebra

    The sum of three consecutive natural numbers is 966. Find the numbers.
  47. Chemistry

    A 150.0 mL sample of a 1.50 M solution of CuSO4 is mixed with a 150.0 mL sample of 3.00 M KOH in a coffee cup calorimeter. The temperature of both solutions and the calorimeter was 25.2°C before mixing and 31.3°C after mixing. The heat capacity of the calorimeter is 24...
  48. Math

    Would you add the 1/16 inch to the 8 1/2 inch to account for each cut and then divide by the 32 FT 10 1/2 inch? or what? I'm confused on how to go about doing the problem.
  49. Math

    How do you account for the 1/16 inch cuts?
  50. Math

    A cable is 32 feet 10 1/2 inches long is to be cut into 8 1/2 inches lengths. Allow 1/16 inch for each saw cut.
  51. precalculus

    thank you
  52. precalculus

    use pascal's triangle to expand the expression (2x-3y)^3
  53. college precalculus

    so one is arithmetic number two is geometric number three is neither?
  54. Pre-Calculus

    f(x) is a sinusoidal curve with maximum at f(0)=10 and next minimum at f(6)=0. Find the equation?
  55. Physics

    Calculate the work required to pull a wagon along a horizontal road for 4.0x10^2 m at a constant speed of 3.0 m/s if the force of friction is 8.0 N.
  56. Math Help

    Hi! I need help with this practice problem. My teacher gave us the answer, "2cot u" BUT she wants us to figure out why that's the correct answer. I'm having some trouble with this and could really use some help. Thank you! Problem: 1+ sec u/tan u - tan u/1+...
  57. Chemistry

    The following questions relate to the chemical equation shown below. Since this is a multi-stage question, be sure to write down the balanced equation and the values for deltaHo and deltaSo before proceeding. A2(g) + 3 B2(g) → 2 AB3(g) deltaHo = -217 kJ mol-1 deltaSo = -...
  58. Chemistry

    Part 1 of 2 Write the balanced molecular equation for the reaction between iron metal (the nail) and aqueous copper II sulfate and classify this reaction. Include the states: solid (s), liquid (l), aqueous (aq), or gas (g). Use your observations to help you determine the ...
  59. Chemistry

    A cell exhibits a standard Ecell of 0.35V at 298K. What is the value of the equilibrium constant for the cell reaction if n = 2?

    Nice one!
  61. Computers

    Sell it and get a proper PC.
  62. Math

    Hi I am Richard , on this problem mark`s has 20 students and he changes it to 20% percent and that is his error.
  63. Math

    he the 20 students and change it to 20% to 200.
  64. physics

    A ball is rolling on a table and leaves the end side of the table with a velocity of 1.5 m/s. The table is 0.70 m high and the ball has a mass of 0.850 kg. What's the speed of the ball when it hits the ground? What equation should I use?
  65. Algebra

    Let "m" be the number of modern rockers. INEQUALITY: 15c+12m<=3000, c>=0, m>=0
  66. Law of Sines

    And steve sorry I didn't read the whole answer.
  67. Law of Sines

    Oh nvm thanks Damon.
  68. Law of Sines

    Thanks! I should have mentioned this in the question, but the answer sheet asks for two values of angle A rather than 1.
  69. Law of Sines

    In Triangle ABC, a=15cm, c=9cm, and angle C= 35 degrees. Find b and angle b. (Recall sin theta= sin (180 degrees-theta). I'm not sure how to approach this.
  70. Physics

    The wavelength of a stationary wave is 36.0cm. What is the distance between a node and the next anti -node
  71. physics

    According to the question:the hill rises at 37.7m to the vertical [y-axis] and 100m to the horizontal[x-axis] in the process a right-angle triangle is obtain and an angle of 90 is also obtain. 90 is the angle inclined at the horizontal
  72. Trigonometry

    If the distance covered by an object in time t is given by s(t) = t^2 + 5t , where s(t) is in meters and t is in seconds, what is the distance covered in the interval between 1 second and 5 seconds?
  73. Physics

    Sorry, there was a typo. *51 degrees opposite the 150 cm side.
  74. Physics

    What is the value of each of the angles of a triangle whose sides are 95, 150, 190 cm in length? I have tried to do this problem, don't get me wrong, but I don't really know where to go. Can someone tell me how to even approach this problem? The textbook states that ...
  75. Math

    Roberto Wins- 1/4 Roberto Loses- 3/4
  76. english

    Your question is confusing. Please go further in detail.
  77. Ratio of two triangles

    What would the ratio be if the first triangle has sides of 4cm, 8cm, and 12cm and the second triangle had sides of 1cm, 2 cm, and 3 cm? Would the ratio be 4:1 or 1:1/4?
  78. Physics

    please help asap
  79. Physics

    A ladder, 5.0 m long, leans against a frictionless wall at a point 4.0 m above the ground. A painter is climbing up the ladder. The mass of the ladder is 12.0 kg and the mass of the painter is 60.0 kg. The ladder begins to slip at its base when the painter is 70 % of the way ...
  80. Chemistry

  81. geometry

  82. Math

  83. History

    when an Ibo-led military council proclaimed a centralized dictatorship
  84. Science

    Hannah is comparing a rock from a riverbed and a rock from deep underground. One is very smooth, and the other has very rough edges. Explain why each rock was probably found in that location.
  85. Earth Science

    ummm A?
  86. Earth Science

    My first guess was A but then i read B this is confusing
  87. Math Help

    Was #1 correct?
  88. Math Help

    I got #1 C, #2 D and #3 $6.50?
  89. Math Help

    1.) You have $22 in your bank account, and you deposit $11.50 per week. Your cousin has $218 in his bank account and is withdrawing $13 per week. The graph of this problem situation intersects at x=8. What does this mean? A. In 8 weeks, you will have triple the amount of money...
  90. Math


    How to prepare a 500ml 0.2M NaOH solution from 2.0M NaOH solution
  92. Stats

    A production process produces an item. In a recent study, the company found that 20% of all items produced were defective. Each item is inspected before being shipped. 10% of the items were misclassified( labeled as defective when they were good or labeled good when they were ...
  93. Statistics

    A production process produces an item. In a recent study, the company found that 20% of all items produced were defective. Each item is inspected before being shipped. 10% of the items were misclassified( labeled as defective when they were good or labeled good when they were ...
  94. science

    an object with a volume of one cu ft , weighing 150 lbs. is embedded in the sediment at a depth of 99 fy. in the ocean harbor. the object is best lifted to the surface by
  95. Macroeconomics

    Graph the following aggregate supply and demand curves (be sure to draw to scale). Real GDP (in $ trillions) Price Level Supplied Demanded Increase / Decrease 100 4 16 110 10 15 140 14 12 200 15 6
  96. Math

    An airplane is flying at a velocity of 300km/h S30degW in a wind blowing at a velocity of 50km/h S20degE. What is the true speed and direction of the plane?
  97. chemestry

    How many grams of O2 are needed to produce 45.8 grams of Fe2O3 in the following reaction? 4Fe(s)+3O2(g) - 2Fe2O3(s)
  98. quantitative rsearch

    A manufacterer of computers designed to aid social scientists in analyzing rsearch data claims that are operational for at least 80% of the time . during the course of the year one computer was operational for 270 days. test, at the 1% CONFIDENCE LEVEL, whether the ...
  99. physics

    IF A 0.5 Kg baseball(at rest) is hit by a bat with a force of 200.0 N what is the magnitude of the baseball just as it is leaving the bat?
  100. statistics

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