Posts by Kevin

Total # Posts: 1,330

  1. Physics

    A hunter wishes to cross a river that is 1.6 km wide and flows with a speed of 5.0 km/h parallel to its banks. The hunter uses a small powerboat that moves at the maximum speed of 11 km/h with respect to the water . What is the minimum time necessary for crossing ?
  2. Sociology

    Describe the demographic characteristics of the poor in the United States. What are some possible explanations for this distribution?
  3. Chemistry

    For the reaction HCONH2(g) --> <--NH3(g) + CO(g), Kc = 4.84 at 400 K. If delta H for this reaction is 29 kJ/mol, find Kc at 500 K. The answer is 27 I just don't know why.
  4. science

    A hawk building its nest on an arm of a saguaro cactus is an example of
  5. Science (Chem)

    Given below are aqueous solutions of strong electrolytes. For each solution, specify the concentration of each ion 0.15 M NH4NO3 (aq) 0.120M Mg(NO3)2(aq)
  6. Chemistry

    Given below are aqueous solutions of strong electrolytes. For each solution, specify the concentration of each ion 0.15 M NH4NO3 (aq) 0.120M Mg(NO3)2(aq)
  7. Chemistry

    A potassium metal has a work function F = 4.41 x 10-19 J. Calculate the velocity of electrons emitted by exposing the metal to radiation of wavelength 300 nm.
  8. Chemistry

    Thanks bob that was my problem
  9. Chemistry

    A 1.50 kg sample of a metal sample absorbs 43.5 kJ of heat, resulting in a Temperature rise of 65.0 °C. What is the specific heat capacity of the metal? M=1.50kG Q=43.5kJ dT=65C
  10. Chemistry: Equilbrium

    How does adding NH3 to the reaction below affect the equilibrium of the reaction? N2(g) + 3H2(g) <=> 2NH3(g) Increasing the amount of NH3 will make Q larger than K. A net reaction occurs in the direction to increase NH3, or the forward reaction. Increasing the amount of ...
  11. Chemistry: Equilibrium

    What is the significance of a very large Kp value on the equilibrium concentration of H2 in the reaction: 2H2(g) + O2(g) ->2H2O(g)? <- There is very little H2 at equilibrium. The amount of H2 is always equal to the amount of O2 at equilibrium. The amount of H2 does not ...
  12. Chemistry

    In a titration experiment, 15.0 mL of 0.10 M Ba(OH)2 is required to titrate a 10.0 mL of an unknown solution of HNO3. Calculate the concentration of the HNO3 solution using the data. 2HNO3 + Ba(OH)2 ® Ba(NO3)2 + 2H2O
  13. Chemistry

    Ok i think i got it, Cu in the compound is +2 and Mg in the compound is +2 So Cu is the OD and Mg is the RA
  14. Chemistry

    My problem is the CU(NO3)2 and Mg(NO3)2 Mg alone is 0 and Cu alone is 0
  15. Chemistry

    For the following redox reaction, identify the oxidizing agent and the reducing agent. Cu(NO3)2 (aq) + Mg(s) ® Cu(s) + Mg(NO3)2 (aq
  16. Science (Chem)

    So I did 10/74.55 to get 0.13414 then /0.150 X 1000 = 894.254mL
  17. Science (Chem)

    Calculate the volume (in mL) of a 0.150 M KCl(aq) solution that contains 10.00 g KCl
  18. Science

    a black car and a white car are sitting in the Sun, why does the black car get hotter
  19. Chemistry

    Given the following data for a hypothetical reaction: M3+ (aq)+ L-(aq) ? [ML]2+(aq); calculate the equilibrium concentration of [ML]2+in the trial solution and Kc based on this single trial run of the equilibrium reaction. Standard solution data: [ML]2+std = 0.0500 M abs [ML]2...
  20. Algebra

    What are the domain and range of the function? f(x)=^3?(x?3) Domain: (??,?) Range: (??,?) Domain: [3,?) Range: [0,?) Domain: [0,?) Range: [3,?) Domain: [3,?) Range: (??,?)
  21. Physics

    A tennis player hits a tennis ball (m = 0.0550 kg) with a force of 32.2 N over a time interval of 0.22 s. If the ball as a velocity of 42.2 m/s before being hit and 87.8 m/s after being hit, how much work did the tennis player do?
  22. Math

    A recipe that makes 10 mini loaves of banana bread calls for 1 1/4 cups flour. How much flour is needed to make 2 dozen
  23. Chemistry

    So is the answer the atomic number is 66 and 70?
  24. Chemistry

    What is the mass number for a neutral atom that has an atomic number of 33 and 35 neutrons? How do you get the answer
  25. Geometry

    1. If line JK is perpendicular to line XY at its midpoint M, which statement is true? a) JX = KY b) JX = KX c) JM = KM d) JX = JY Is it c? 2. What information is needed to conclude that line EF is the bisector of ?DEG? a) m?DEF = m?DEG b) m?FEG = m?DEF c) m?GED = m?GEF d) m?...
  26. History

    Is it a
  27. Math

    What's 9 + 10?
  28. Chemistry

    How do you calculate the heat gained by the calorimeter after adding aluminium?
  29. Math

  30. Math

  31. Math

  32. Physics

    A ball is dropped from a height h without air resistance. If the ball falls a distance of h/2 in a time t, how much time is required to fall the remaining h/2? Could you show steps because I don't understand how to work the problem. Thank you.
  33. Algebra

    Alex is two-fifths as old as Clara. The sum of their ages is 56. How old is Alex?
  34. physics

    If object B is dropped from a height of 100 m while moving horizontally at 115 m/s. How much time will it take for object B to hit the ground? (round answer to the tenth's place and use "s" to describe your answer)
  35. PreCalculus

    sin isnt an identity to begin with and i got sin^2 x + cos^2 x = 1 the ansswer says its what i got
  36. PreCalculus

    Prove the following to be an identity (cotx + cscx)*(1-cosx)=sin x
  37. chemistry

    Hydroselenic acid in formula form is H2SeO4?
  38. precalculus

    sin^2 x + cos^2 x = 1 using that, derive what the cot^2 x would equal to. would it be csc^2 x - 1 = cot^2 x
  39. math

    4cosx + 3 = 0
  40. S.S.

    Who are the new United States governments of 2017?
  41. Statistics

    The Jones family was one of the first to come to the U.S. They had 9 children. Assuming that the probability of a child being a girl is .5, find the probability that the Jones family had at least 5 girls.
  42. Statistics and Probability

    A ticket in a typical lottery like Lotto 6/49 is usually $2. The probability of winning Lotto 6/49 is 1 in 13,983,816. The payoffs (jackpots) are usually in excess of $1 million. Suppose that you buy one ticket for $2 and the jackpot is $1 million. What is your expected value ...
  43. physics

    The mars rover opportunity approached Mars on January 24th, 2004 and was moving with a velocity of 5.4km/s when it hit the atmosphere on its way to the surface at Miridani Planum. i)convert this speed to miles/hr. ii) If it took the lander 6 minutes to hit the surface of Mars...
  44. Language Arts

    The black hawk is wrong look at number 3 he said B but thats the stupid answer just look closly at it
  45. algebra

    identify if the given functions are one to one 1. f(x)=x^3-7x 2. g(x) = square root x-3+1 3. h(x)=4x^4-2x^2+11
  46. Physics

    An egg is thrown nearly vertically upward from a point near the cornice of a tall building. It just misses the cornice on the way down and passes a point a distance 34.0 m below its starting point at a time 5.00 s after it leaves the thrower's hand. Air resistance may be ...
  47. College Algebra

  48. Policy

    What was the Peel Commission and what were the recommendation about Palestine?
  49. Middle East

    During the Colonial history of the Middle East, what were some of the countries interested in the Middle East?
  50. Science

    Can someone help me come up with a way the lithosphere and cryosphere interacts? I already have permafrost.
  51. Geometry

    N is between points M and P. MN = 17 NP = 3y MP = 5y + 9 Find MP.
  52. Chemistry

    Calculate % of lowering of vapour pressure if 36 g glucose is added in 312g of benzene
  53. Physics

    Suppose you are provided with 500 dice.calculate the number of throws that is equivalent to one half life and the decay costant for the process.under radioactivity decay analogue experiment
  54. Math (NEED HELP ASAP)

    She's Longing For An Answer, & So Am I.
  55. Physics

    To make ice cubes you fill am ice tray with 150g of water at 20°C. How much energy must be removed from the water to create ice cubes at a final temperature of -10C
  56. Algebra

    Find the zeros of the function f(x)=(m^2-9)(9m^2+24m+16)
  57. Algebra

    A rectangle's width is 6 inches less than its length. If it's area is 216 square inches find the dimensions of the rectangle. Write an equation and solve
  58. Algebra

    A triangle has a height that is 4 inches less than its base. If the triangle has an area of 86 square inches, set up and resolve an equation to find its base and height.
  59. social studys

    Lmaoo Mr. O'Hearn is my teacher
  60. Math

    I'm a dad trying to help my daughter. Question is kx+6y-5=0 3x+2y+4=0. Need to find 1. Value of k such that the lines are perpendicular and 2. The angle of inclination of the second line given
  61. Math

    Why is log1/a(x), a reflection over the x axis?
  62. Math

    expanded form
  63. History

    Please help me please Mrs. Sue.
  64. History

    Who are the United States governments of 2017?
  65. Algebra

    A rectangle's length is 6 less than twice its width. The perimeter of the rectangle is 36 units. Set up and solve a system of equations to determine the length and width.
  66. Algebra

    A boat traveled 180 miles downstream and back. The trip downstream took 10 hours. The trip back took 30 hours. Find the speed of the boat in still water and the speed of the current. Solve each system using any method
  67. Math

    Describe transformations of f(x)=-f(2-x)
  68. Calculus

    Air is being pumped into a spherical hot air balloon at a rate of 50 cm^3/min. Determine the rate at which the radius of the balloon is increasing when the diameter of the balloon is 200 cm.
  69. Help math

    find 2 exponential functions with asymptote of y=80 , with points (0,176) (1,169) (3,156) (5,146) (20,101) (30,90) (60,81).one should have the base of "e"
  70. Pre calculus

    find 2 exponential functions with asymptote of y=80 , with points (0,176) (1,169) (3,156) (5,146) (20,101) (30,90) (60,81).one should have the base of "e"
  71. 4th grade math

    We're going to add all the time she spent doing all these activities. When adding fractions remember to first find their least common denominator. 10 is the LCD. Therefore, 1/5 becomes 2/10 3/10 remains the same because it already has a 10 in the denominator 4/5 becomes 8/...
  72. Calculus

    A hang glider is standing at the top of a 3,000 foot cliff. The hang glider jumps off and begins to descend at a constant rate of 50 feet per second, how fast is the area of the triangle formed by the cliff, the hang glider, and the ground changing at the instant when the hang...
  73. Algebra

    When swimming in the direction of the current in a river your average speed is 5 mph. When swimming against the current your speed is 2mph. Find your swimming speed in still water and the speed of the current.
  74. Algebra

    A cashew and raisin mixture costs $2 per pound. You buy a 4.5,pound mixture of cashews and raisins. If cashews cost $2.50 per pound and raising cost $1.25 per pound, how many pounds of cashews and how many pounds of raisins make up the mixture?
  75. Algebra

    John and Kathleen each improved their yards planting rose bushes and shrubs . They bought their supplies from the same store. John spent $228 on 12.rose bushes and 11 shrubs. Kathleen spent $108,on 6 rose bushes and 5 shrubs. Find the cost of one rose bush and the cost of one ...
  76. Algebra

    Write a system of equations to solve each word problem. You deposit a total of $900 in two different accounts. One account provides an interest rate of 5% while the other account provides an interest rate of 8%. If you earned a total of $64.50 in interest between the two ...
  77. Algebra

    Thank you!
  78. Algebra

    Set up a system of equations for each word problem One scuba diver starts at a depth of 12 meters below the water's surface and ascends at a rate of 1 meter per second. A second diver starts at a depth of 15 feet and ascends at a rate of 2 meters per second. After how many...
  79. Math 10C

    Janet needs a rectangular piece of cardboard measuring 21 ft by 24 ft for a school project. a) What is the area of the cardboard in square feet? b) What is the area of the cardboard in square yards? Show your calculations in two different ways. c) The store charges $0.35/m2 ...
  80. Foods and Nutrition

    Which foods contain the most protein?
  81. Physics

    Name any Margins of error that would happen in the lab "Which path requires the most energy? (gas)
  82. Math

    The number has four digits. It is greater then 11,but less then 12. The sum of the four digits is 13. The digit in the hundreds place is 6. What is the number
  83. French

    Thank You Ms. Sue
  84. French

    How does "Le Louvre", a museum in Paris, France connect to French Culture?
  85. Math

    The coordinates of the midpoint of the line AB are (1, 2). The length of the line AB is 10 units. If the gradient of AB is 0, find the coordinates of A and B
  86. math

    i did 65 miles=1 hour 63360 in=1 mile 1 hour= 60 minutes 1 rev=30 pi in the end after multiplying i got 728.3 rpm, is this correct?
  87. math

    An automobile is traveling at 65 mph. If each tire has a radius of 15 inches, at which rate are the tires spinning in revolutions per minute (rpm)? (63360in=1 mile)
  88. Algebra

    Find the value of x so that the line through the points has the given slope (2,2) and (x,9);slope: undefined
  89. Math

    Write an equation in point-slope form to represent the situation. Assume a linear relationship between the given quantities. In 1998, the deer population of a certain area was 1200. In 2006, the population was 2000.
  90. Math

    Find the slope of the line through each pair of points. Simplify as much as possible (-2g,6h), ( 2i,7g)
  91. riddle

  92. pre-Calculus

    Make a conjeture about the symmetry of a) a product of two odd functions b) a product of two even functions c) a product of an odd function and an even function
  93. Pre-Calculus

    Tommy is building a rectangular playpen for his pigs where one side of the play area is a side of his barn. He has enough material to make a fence with a total length of 160 feet. write a función that represents the playpen's área in terms of its length ...
  94. Science

    Where can I find a pie chart that shows the percentage of resources used to generate electricity in the United States in 2015?
  95. Math

    You do not have enough 6-inch beads to make the rope, so you will use 10-inch beads instead. Write and solve an inequality that represents the number of 10-inch beads that you can use.
  96. physics

    A spring gun shoots out a plastic ball at speed v0. If the ball's speed is increased by a factor of 2, what distance must the spring have been compressed?
  97. Math

    How many volleyball games would Rana have to schedule if there were 10 teams in the league and each team played each other twice?
  98. pre-calculus

    Assume that the number of bacteria follows an exponential growth model: P(t)=P0ekt . The count in the bacteria culture was 900 after 20 minutes and 1600 after 30 minutes. (a) What was the initial size of the culture? (b) Find the population after 80 minutes. (c) How many ...
  99. Physics (Mechanics)

    A student of mass M = 62 kg takes a ride in a frictionless loop-the-loop at an amusement park. The radius of the loop-the-loop is R = 19 m. The normal force by the track on the student at the top of the loop-the-loop is N1 = 100 N Find the speed of M at the top of the loop. ...
  100. Physics (Mechanics)

    A 905 kg car moves in a circle of radius 13.1 meters in a flat parking lot. If the car can travel at 9.1 m/s without slipping, what is the force of friction between each tire and the parking lot? What is the coefficient of friction between each tire and the lot? (Remember ...
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