Posts by robert

Total # Posts: 1,032

  1. Science

    A proton accelerates from rest to 3.00x10^6m/s in 1.00x10^-6s in a uniform electric field E. What is the magnitude of the electric field?
  2. Physics

    A cube made ouk and side 15cm floats in water with 10.5cm of it's depth below the surfaces and with it's side's vertical what is density of oak
  3. Physics

    A block cedar has a mass of 200 kg and density of 570 what fraction of the wood will be surface of block is floating in water
  4. Physics

    A space vehicle travelling at a velocity of 6000km/h separates into two parts of mass 1200 kg and 300 kg. The two parts continue moving in the same direction with the lighter section moving at 6200km/h. Making use of the principle of conservation of momentum, determine the ...
  5. Physics

    A racing car of mass 850 kg accelerates from 20 km/h to 160 km/h over a distance of 300 metres. Frictional forces and wind resistance can be assumed to be 800N. Determine the following: (i)The average acceleration (ii)The time taken to accelerate from 20 km/h to 160 km/h (iii)...
  6. Calculus

    How do you take the limit of a composite piecewise function f(f(x))? Only the graph is given. lim f(f(x)) x->2 I figured the way to do it was to find the lim f(x) = C then find lim f(x). x->2 x-> C The simple questions on Khan academy's "Limits of composite ...
  7. Math

    A helicopter drops a box of supplies after a disaster. The function represents the height y (in feet) of the box t seconds after it is dropped. After how many seconds does the box hit the ground? y=100-16t^2
  8. Physics

    The velocity of sound in air is about 330m/s, and in water is about 1700m/s. Calculate the critical angle for sound leaving air and entering water.
  9. Physics 2

    A fisherman notices that his boat is moving up and down periodically rowing to waves on the surface of the water. It takes 3.0 seconds for the boat to travel from its highest point to it's lowest, a total distance of 0.800m. The fisherman sees that the wave crests are ...
  10. Physics

    An observer is located directly between two speakers, located 20m apart. The speakers are in phase with each other, and both are emitting a sound with a frequency of 60Hz. How far away from the centre should the observer move to get the first destructive interference?
  11. Physics

    Sapose active sonar on a stationary ship is used to determine the speed of a ship that is moving away from it. A sonar ping is emitted at a frequency of 1400Hz, and the echo returns with a frequency of 1390Hz.The speed of sound in sea water is approximately 1500m/s. What is ...
  12. physics

    Calculate the speed of a satellite moving in a stable circular orbit about the Earth at a height of 3.004km.
  13. physics

    During an Apollo lunar landing mission, the command module continued to orbit the Moon at an altitude of about 58.6 km. How long did it take to go around the Moon once, in seconds?
  14. Math

    Matter is in a liquid state when its temperature is between its melting point and its boiling point. Suppose that some substance has a melting point of negative 46.81 degrees and a boiling point of 357.63 degrees . What is the range of temperatures in degrees Fahrenheit for ...
  15. English

    Do you mean write not show? I know that when boys help in the kitchen it can help to reduce the burden on girls in the house because part of the cooking and other works that require more strength will be done by the boys.Also,boys will grow to become men who will eventually ...
  16. Math

    An architect make a model of a building with a volume of 1440 cubic centimeters? The length of the model is 15 centimeters and the width is 12 centimeters. How many centimeters tall is the model
  17. combining like terms

    The length of a rectangle is 4.5 units longer than the width,w. Find the perimeter of the rectangle
  18. Math

    measure of angle A and measure of angle B are complementary. measure of angle A = 3x + 12 and measure of angle B = 2x - 22. Find the measure of each angle.
  19. Math

    -6 greater equal to 13 + 5 which of these values of X makes the inequality true -3.9 -1.2 3/13 -7/15 Please help explain answer
  20. Math

    -6 greater equal to 13 + 5 which of these values of X makes the inequality true
  21. Real Estate

    What number less 6% equals 610,000
  22. History

    What inventions were made because of the telegraph?
  23. Social studies

    I need help with lesson 12 unit 2 for seventh grade there is a unit test called Eastern Europe and Russia and unit test 7. Many words offer clues to media bias. Which word below would mostly likely signal bias. A. Was B. Did C. Should D. Might
  24. Organic Chemistry

    Procedure: 1) Accurately weigh approximately 0.40 g of Dimethyl maleate into a 50 mL round bottom flask that possesses a ground glass joint, and record the weight. 2) Dissolve the Dimethyl maleate in 10 mL of methanol, and add approximately 5 drops of 10percent solution (w/v) ...
  25. Organic Chemistry

    Procedure: 1) Accurately weigh approximately 0.40 g of Dimethyl maleate into a 50 mL round bottom flask that possesses a ground glass joint, and record the weight. 2) Dissolve the Dimethyl maleate in 10 mL of methanol, and add approximately 5 drops of 10% solution (w/v) of ...
  26. World History

    what events contributed to the rise and fall of the egyptian empire?
  27. American government

    C and B
  28. math

    A third staircase in a swimming pool has a landing of 18 inches and a vertical rise of 12 inches per step. To the nearest degree, calculate the following measures. a) What is the angle of elevation rounded to the nearest whole degree? b) If the elevation of each step were ...
  29. Math

    Find the vertex focus directrix and axis of symmetry of each parabola y²–8x–6y–3=0
  30. calculus

    Elasticity a) Find the elasticity of the demand function q + 2p = 5000 when p = $1000, and q = 3000. b) How would revenue be affected by a price increase?
  31. physics

    200g of steam at 110°C is condensed, and the resulting water is frozen into ice at 0°C. How much heat was removed?
  32. Chemistry

    A fixed amount of oxygen gas is held in a .500 L tank at a pressure of 4.09 atm. The tank is connected to an empty 1.50 L tank by a tube with a valve. After this valve has been opened and the oxygen is allowed to flow freely between the two tanks at a constant temperature, ...
  33. ap

    it doesn't matter i just needed an answer to get an idea of what i'm going to say
  34. ap

    What is the most accurate description of human nature?
  35. History

    How does Galileo defend himself against these charges of heresy by the Inquisition?
  36. Statistics

    Q1:(a) Make a relative frequency table of the data. Enter your answers to three decimal places. Cell Phone Owned Relative Frequency Android smartphone iPhone smartphone Blackberry smartphone Cell phone not smartphone No cell phone Total (b) Round your answers to the following ...
  37. pre calc

    The number N of bacteria in a culture at time t (in hours) grows exponentially according to the function N(t) = 1000e^0.01t When will the number of bacteria reach 1700? I though you would do 1700=1,000^e0.01t and solve for t but i keep getting the wrong answer can someone ...
  38. pre calc

    The population of a colony of mosquitoes grows exponentially according to the function P(t) = P0ekt 1. If there are 1,000 mosquitoes initially and there are 1800 after 1 day, what is the size of the colony after 3 days? 2. How long will it take the colony to reach 10,000 ...
  39. computer programming

    Design the logic for a program that allows a user to enter any amount of numbers up to 10 or until a sentinal value of -1 is entered. Then the program displays the count of the numbers entered and numeric average of the numbers (not including the -1 of course). After display ...

    if the speed of a car is increased from 90km/h to 120km/h, the time is reduced by one hour to reach the destination. Calculate the distance between the two towns.
  41. Physics

    Huck Finn walks at a speed of 0.60 m/s across his raft (that is, he walks perpendicular to the raft’s motion relative to the shore). The raft is traveling down the Mississippi River at a speed of 2.20 m/s relative to the river bank. What is Huck’s velocity (speed and...
  42. Physics

    Also find the final velocity in y (v_fy) of the shot just before it hits the ground.
  43. Physics

    A projectile is shot from the edge of a cliff 145m above ground level with an initial speed of 65.0 m/s at an angle of 37.0° with the horizontal. How far did the shot go horizontally?
  44. Physics

    Your gun is perfectly level with a monkey at a distance of 55 m. Your bullet is shot perfectly horizontal at a speed of v_0=38 m?s at the exact moment the monkey lets go of the branch. How far does the monkey fall before the bullet hits it?
  45. Physics

    During your trip in question 10, you encounter some construction. In 25 seconds, you have to slow from 70 mph to 55 mph. What is your acceleration in mph/s?
  46. Physics

    After today’s test, you are going to meet some friends at Disney World. The total distance to Disney World is 68 miles. If you make it there in 72 minutes, what is your average velocity in miles per hour?
  47. Physics

    Assume you have a canon aimed straight up. The cannonball is shot at a velocity of v_0=69 m/s. How high does the cannonball go? How much time does it take the cannonball to reach that height?
  48. College Algebra

    x+2y=0 x+3y+z=1 -4x-y-z=23
  49. math

    i need ratios of 5/6
  50. Math

  51. Math

    Roberto wants to reduce a drawing that's is 12 inches long by 9 inches wide.if his new drawing is 8 inches long. How wide will it be
  52. Math

    An 8.5 centimeter green bean pod contains peas that average 0.45 centimeter in diameter. How many peas are in the pod
  53. Social studies

    It is indeed B A B A
  54. Math

    He is supposed to need 2 liters, not 22! Sorry for the typo
  55. Math

    A chemist needs 22 liters of a 14% acid solution. He has a 10​% solution and a 20% solution available to form the mixture. How much of each should be used to form the 14​% ​solution? I'm having a really hard time forming an equation for this. I've ...
  56. Chemistry

    An element has three stable isotopes. One has a mass number of 63 and an abundance of 50%. The second has a mass number of 65 and an abundance of 30%. The third has a mass number of 67 and an abundance of 20%. Calculate the relative atomic mass of this element. I am so ...
  57. Biology

    why is protein folding important to enzyme activity?
  58. Social Studies (Check Answers)

    @LOL How would it be A and D if Mrs. Sue said 1 was C?
  59. math

    32 cans for 7 dollars how much per can
  60. geography

  61. Social studies answer check please

    @Blupo is right.
  62. Linear Algebra

    Thank you very much Reiny I was stumped on that but thanks to your assistance I was able to solve the problem. Thank you very much!
  63. Linear Algebra

    The Vector v has a length of 15 and points at an angle of 30 degrees. The Vector u has a length of 17 and points at an angle of 55 degrees. What is u*v? I know to get my answer I need to use this format |u|*|v|*cos(theta) however I am stuck at setting up my vectors I only know...
  64. algebra 1

    whoops typo on your last problem I meant divide by 4 not 4x my apologies.
  65. algebra 1

    For your first question think about it like this -7+9=2 and -9+7=-2. -2 and 2 are not equal. For 4x-3=19 you need to add 3 to both sides of your equation and then divide by four on both sides to get your answer for x then plug in x to your equation and see if it equals 19 in ...
  66. Social Studies

    @I_Dont_Have_A_Name Thanks.
  67. Math

    1. B 2. D 3. C 4. B 5. C
  68. Math

    Yes its B
  69. Math

    Suppose that A and B are independent events such thatP(A)=.50 andP(B)=.30 . Find and P(A U B) and P(A upside down U B) .
  70. physic

    Does anyone actually answer questions on here?
  71. World History

    chicken noddles soup is very awesome to a lot of people pasta
  72. Mayh

    Bert gave me 1/2 of the candy bar then I gave 1/2 of what I have to my sister What fraction of the whole candy bar did my little sister get and what percent did she get
  73. Math

    8 short responses,12 multiple choice. Melanie is wrong because 5+6 doesn't add up to 20 questions.
  74. Communication for Business

    1. Introduction A. Attention getter B. Area you are interested in career filed C Preview of points covered in body 11. Body A. Career field 1. Name of person interviewed
  75. Communication for Business

    Please could you help me with a good attention getter for a presentation on how interviews were done
  76. Chemistry

    If the heat of combustion for a specific compound is -1250.0 kJ/mol and its molar mass is 35.39 g/mol, how many grams of this compound must you burn to release 352.40 kJ of heat?
  77. Algebra

    Okay so first you find the 363 square root of 363. Then you find the square root of 27. Then you apologize to your connections academy teacher for cheating online. And there you have it! All three steps!
  78. Math

    Gina has 4 red ribbons, 6 times as many blue ribbons as green ribbons, and 1/4 as many green ribbons as red ribbons. How many ribbons does she have in all?
  79. Physics

    Two metallic spheres of mass .001 kg hang from a point by .3 m strings. Each is given the same amount and sign of charge. After equilibrium is reached, they each make an angle of 20 degrees relative to the vertical. Determine the amount of charge in each sphere.
  80. math

    how do you write twenty million three hundred thousand
  81. physics

    What is the mass which causes a spring of k = 100 N/m to stretch by 10 cm?
  82. Math

    What point on the unit circle corresponds to -5pi/4? A. (-Root2/2, Root2/2) B.(-Root3/2, 1/3 C.(-1/2, Root3/2) D.(0,1) D?
  83. Geography

    This dick
  84. Calculus

    When the particle reverses direction, this means that there is a sign change in the velocity of the particle or s'(t). s'(t) = 6t^2 - 42t + 60 Setting it equal to 0 to find critical points; 6t^2 - 42t + 60 = 0 t^2 - 7t + 10 = 0 (t-5)(t-2) = 0 t-5 = 0 t = 5 t-2 = 0 t = ...
  85. math

    a boy runs 18.4 miles in 4.5 hours, how many miles can he run in 1 hour?
  86. Science

    HES RIGHT!! I MADE A 100%
  87. Finance

    Your program has a research and development project scheduled to start in January 2014 which is expected to take 40 months to complete. The project is expected to cost a total of $150 million (then-year dollars), with cost expected to be incurred as follows: FY Cost to be ...
  88. Math

    How'd you get 1,150,000? The answer would be 9583 I think?
  89. Math

    The Japanese yen corresponds to the american dollar. If the exchange rate is 150 Yen for 1 Dollar, then A japanese car sold in america for $10,000 will bring in 1,500,000 yen. If the exchange rate changes to 120 yen for each dollar, then what price in dollars would the car ...
  90. Math

    I say the answer is 53
  91. College algebra

    Matt and Jena, working together, can clean the house in 9 hours. Working alone, Jena takes three times as long as Matt. How long does it take Matt to clean the house.
  92. Grammar

    When ending a letter to a high gov't official with the phrase 'Respectfully Submitted', are both words capitalized, or just the first?
  93. math 8

    tabular method
  94. AP Physics

    A 5.86 kg block initially at rest is pulled to the right along a horizontal surface by a constant, horizontal force of 14.4 N. The coefficient of kinetic friction is 0.14. The acceleration of gravity is 9.8 m/s 2 . Find the speed of the block after it has moved 4.98 m. Answer ...
  95. Math

    jeff rode bike 5 times as many miles as Vin. together they rode 18 miles. how many miles did each boy ride
  96. Cheistry

    single titration was performed which required 11.82 ml of .1 M Na2S2O3 the density of the original undiluted bleach unknown was 1.04 g/ml calculate the number of moles of ClO- in the sample titrated ClO- + 2I- + 2H+ === I2 + Cl- + H20 I2 + 2S2O2/3- === 2I- + S2O2/6-
  97. Life Skills

    How Does Empathy Positively Affect Education?
  98. Chemistry

    Are my answers correct? Calculate the molarity: a) 0.500 mol of NaOH in 2.45 L of solution. b) 24.1 g of NaCl in 853 mL of solution. a: 0.2 M b: 0.49 M
  99. Adding and Subtracting Rational Numbers

    I have the same problems the question is find the sum or difference
  100. Physical Science

    If a skydiver has a forward velocity of 40 m/s, what is the forward velocity after one second? What is the downward velocity after one second?