Most popular questions and responses by Rick
  1. Statistics

    According to the Pew Internet &American Life Project. 75% of American adults use the internet. The Pew project authors also peported on the percentage of Americans who use the internet by age group. The data in the in the agefile group was consistent with

    asked on April 12, 2012
  2. Phyiscs

    A man claims he can safely hold on to a 9.7-kg child in a head-on collision with a relative speed of 112-mi/h lasting for 0.12 s as long as he has his seat belt on. (a) Find the magnitude of the average force needed to hold onto the child. HELP

    asked on November 25, 2009
  3. Chem II

    2.5 mol NOCl(g) was placed in a 2.50 L reaction vessel at 400 degrees C. After equilibrium was established, it was found that 28% of the NOCl had dissociated according to the equation: 2NOCl(g)2NO(g)+Cl2(g) Calculate the equilibrium constant, Kc, for the

    asked on January 30, 2007
  4. english 1

    What is one way that “The Maori: Genealogies and Origins in New Zealand” contrasts with “The Raven and the First Men: The Beginnings of the Haida”?

    asked on October 24, 2014
  5. Math

    Find the length of the curve r(t)=sqrt(2)ti + e^tj + e^-tk, 0

    asked on July 6, 2015
  6. math

    a model rocket is projected straight upward from the ground level. It is fired with an initial velocity of 192 ft/s. How high is the rocket after 10 seconds? When is the rocket at a height of 432 feet? What is the maximum height of the rocket? When will

    asked on April 9, 2015
  7. Maths

    An aeroplane is flying horizontally directly towards the city at an altitude of 400 metres. At a given time the pilot views the city lights of Melbourne at an angle of depression of 1.5 degrees. Two minutes later the angle of depression of the city lights

    asked on September 26, 2017
  8. Chemistry

    What volume of 0.716M KBr solution is needed to provide 10.5g of kBr?

    asked on May 5, 2012
  9. math

    The average middle-distance runner at a local high school runs the mile in 4.5 minutes, with a standard deviation of 0.3 minute. The percentage of a runners that will run the mile in less than 4 minutes is %.

    asked on July 31, 2012
  10. Algebra

    The Oliver Company plans to market a new product. Based on its market studies, Oliver estimates that it can sell up to 4,500 units in 2005. The selling price will be $2 per unit. Variable costs are estimated to be 20% of total revenue. Fixed costs are

    asked on February 19, 2012
  11. physics question

    A spacecraft in the shape of a long cylinder has a length of 100 m, and its mass with occupants is 1660 kg. It has strayed too close to a black hole having a mass 103 times that of the Sun (Msun = 1.99 x 1030 kg). The nose of the spacecraft points toward

    asked on March 18, 2010
  12. Chemistry

    A 5.00 mL aliquot of vinegar (acetic acid, FW = 63 g/mol) was diluted and titrated with 0.1104 M NaOH requiring 32.88 mL. If the vinegar has a density of 1.055 g/mL, calculate its acidity as % acetic acid

    asked on June 22, 2014
  13. physics

    A law enforcement officer in an intergalactic "police car" turns on a red flashing light and sees it generate a flash every 1.5 s. A person on earth measures that the time between flashes is 2.9 s. How fast is the "police car" moving relative to the earth?

    asked on April 14, 2008
  14. Physics

    A force vector F of magnitude 12N is applied to a FedEx box of mass m2=1kg. The force is directed up a plane tilted by theta=37 degrees. The box is connected by a cord to a UPS box of mass m1=3kg on the floor. The floor, plane, and pulley are frictionless,

    asked on July 6, 2010
  15. chemistry

    propanoic acid ch3ch2cooh is a weak acid which has a value for dissociation content of ka = 6.3 x 10^-6 calculate the pH of an aqueous solution of propanoic acid containing 37 g of propanoic acid per litre. i'm stumbled on this one.. i calculated that the

    asked on July 27, 2010
  16. physics

    A projectile is shot straight up from the earth's surface at a speed of 1.50×104 .

    asked on November 30, 2012
  17. physics

    An electric power line carries a current of 1600 A in a location where the earth's magnetic field is 4.0*10-5 T. The line makes an angle of 75° with respect to the field. Determine the magnitude of the magnetic force on a 130 m length of line.

    asked on February 10, 2008
  18. Pre-Cal

    This exercise is based on the following table, which lists interest rates on long-term investments (based on 10-year government bonds) in several countries in 2008. Assuming that you invest $12,000 in the Japan(1.5%), how long (to the nearest year) must

    asked on February 29, 2012
  19. Chemistry(URGENT!)

    determine whether the following salts will form acidic, neutral or basic solutions in water. Na2HPO4 CaNO2 NH4CH3COO Al2SO4 NaF Please, i need the answer to this question within 2 hours of when i post this!

    asked on July 28, 2010
  20. Chemistry

    I'm having trouble with the following question, any help would be greatly appreciated. A voltaic cell consists of a Zn/Zn^2+ half-cell and a Ni/Ni^2+ half-cell at 25 C . The initial concentrations of Ni^2+ and Zn^2+ are 1.30 M and 0.100 M , respectively.

    asked on April 17, 2011
  21. physics

    In astronomy, distances are often expressed in light-years. One light-year is the distance traveled by light in one year. The distance to Alpha Centauri, the closest star other than our own sun that can be seen by the naked eye, is 4.7 light-years. Express

    asked on March 3, 2008
  22. Physics

    A 1kg pigeon sits on the middle of a clothesline whose supports are 10m apart. The clothesline sags by 1 meter. If the weight of the clothesline is negligible, find the tension in it.

    asked on September 9, 2014
  23. physics

    A person stands 4.4 m in front of a wall that is covered floor-to-ceiling with a plane mirror. His eyes are 1.9 m above the floor. He holds a flashlight between his feet and manages to point it at the mirror. At what angle of incidence must the light

    asked on March 20, 2008
  24. math

    Is 499.79 million = 499,790,000? Is 15,099 million = 15,099,000,000?

    asked on December 11, 2018
  25. physics

    A box slides down a frictionless 35 degree incline. Determine its acceleration. If the incline is 10.0 m long and the box starts from rest, how much time does it take to get to the bottom?

    asked on November 6, 2016
  26. physics

    The average power dissipated in a stereo speaker is 54 W. Assuming that the speaker can be treated as a 4.0- resistance, find the peak value of the ac voltage applied to the speaker.

    asked on January 30, 2008
  27. physics

    an electron is accelerated from rest through a potential difference V. If the electron reaches a speed of 9.11*x10^6 m/s, what is the potential difference?

    asked on May 13, 2014
  28. Physics

    A man lies on a plank of negligible mass supported by two scales 2.50 m apart. His head rests on the left scale which is also the axis of rotation. If the left scale reads 290 N and the right scale reads 122 N calculate his mass.

    asked on November 27, 2012
  29. physics

    The human eye is most sensitive to light having a frequency of about 5.3*10^14 Hz, which is in the yellow-green region of the electromagnetic spectrum. How many wavelengths of this light can fit across the width of your thumb, a distance of about 2.0 cm?

    asked on March 5, 2008
  30. Maths

    A movie theatre seats 200 people. For any particular show, the amount of money, m, the theatre makes is a function of the number of people, n, in attendance. If a ticket costs $12 and the cost to the theatre to run one show is $120, state the domain and

    asked on April 21, 2015
  31. Chemistry

    1)Which thermochemical equation and data does not agree with the other two written? a) 2NO (g)+ O2 (g) ->2 NO2 (g) deltaH=-169.8 b) NO (g) + 1/2 O2 (g) -> NO2 (g) delta H = -56.6 c) 4 NO2 (g) -> 4 NO (g) + 2 O2 (g) delta H = +226.4 d)all three equations

    asked on January 22, 2012
  32. physics

    An owl has good night vision because its eyes can detect a light intensity as small as 5.0*10^-13 W/m2. What is the minimum number of photons per second that an owl eye can detect if its pupil has a diameter of 7.0 mm and the light has a wavelength of 545

    asked on April 14, 2008
  33. Physics

    A wire with cross sectional area 1.00 cm2 stretches 0.500% of its length when it is stretched with a tension of 20.0 N. What is the Young's modulus of this wire?

    asked on October 28, 2016
  34. Physics

    How many electrons must be removed from an electrically neutral silver dollar to give it a charge of +2.8 µC?

    asked on January 24, 2008
  35. physics

    A car at the Indianapolis-500 accelerates uniformly from the pit area, going from rest to 320 km/h in a semicircular arc with a radius of 190 m. 1.) Determine the tangential acceleration of the car when it is halfway through the turn, assuming constant

    asked on September 20, 2010
  36. English

    A question from Sir Knight and the Green Knight After the Green Knight addresses King Arthur and his Knights, King Arthur says, "By Heaven, Sir, your request is strange". What is the Green Knight's request?

    asked on September 19, 2009
  37. trig

    If cos A =1/3 with A in QIV find cscA/2

    asked on February 28, 2008
  38. trig

    Use half-angle formulas to find the exact value for the following cot 75 degrees

    asked on February 28, 2008
  39. physics

    A piece of copper wire has a resistance per unit length of 6.45*10-3 /m. The wire is wound into a thin, flat coil of many turns that has a radius of 0.140 m. The ends of the wire are connected to a 12.0 V battery. Find the magnetic field strength at the

    asked on February 11, 2008
  40. Physics

    A 1kg pigeon sits on the middle of a clothesline whose supports are 10m apart. The clothesline sags by 1 meter. If the weight of the clothesline is negligible, find the tension in it.

    asked on September 9, 2014
  41. chemistry

    a sample of a radioisotope had a mass of 100.0 grams. After exactly 24 days, 6.25 grams remained. The half life of the isotope is _________

    asked on June 3, 2011
  42. trig

    If sin = -3/5 with A in QIV, find cos A/2

    asked on February 26, 2008
  43. Calculus

    400 feet of fencing is to be used to enclose four adjacent pieces of land. What dimensions will produce the largest area?

    asked on October 25, 2014
  44. Busniness Finance

    I am having some difficulties with week four lab. The explanation for problem skips a step and I do not know how to get the answer. (Weighted average cost of capital). As a member of the Finance Department of Ranch Manufacturing, your supervisor has asked

    asked on February 17, 2012
  45. physics

    A 3Kg projectile is fired straight upward from earth's surface with a speed that is one-fourth the escape speed. Neglecting air resistance. a) What is the Kinetic energy of this projectile when it is launched? b) what is the gravitational potential energy

    asked on February 14, 2011
  46. physics

    The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.5 m. The magnetic field of the generator is 0.10 T, and the coil rotates at an angular speed of 25 rad/s. What is the peak emf of

    asked on February 15, 2008
  47. college algebra

    Kepler’s third law. According to Kepler’s third law of planetary motion, the ratio t^2/r^3 has the same value for every planet in our solar system. R is the average radius of the orbit of the planet measured in astronomical units (AU), and T is the

    asked on October 9, 2010
  48. math

    An architect is designing the floors for a hotel. Each floor is to be rectangular and is allotted 720 ft of security piping around walls outside the rooms. What dimensions of the atrium will allow an atrium at the bottom to have maximum area?

    asked on August 16, 2010
  49. Maths

    A square is transformed into a recatangle of perimeter 30 cm, by increasing one side by 3 cm and reducing the adjacent side by 2 cm. Find the length of the square's side.

    asked on October 15, 2017
  50. Pre-Cal

    This exercise is based on the following table, which lists interest rates on long-term investments (based on 10-year government bonds) in several countries in 2008. How long, to the nearest year, will it take an investment in Germany(4.3%) to triple its

    asked on February 29, 2012
  51. math

    how much money would have to be invested in an account at 3.98% annual interset to achieve a balance of 25,000 in 17 years if a. The account pays simple interest b. the account compound interest qrtly c. the account compounds interest continuously

    asked on January 1, 2011
  52. physics

    In a lightning bolt, 13 C of charge flows in a time of 1.5*10-3 s. Assuming that the lightning bolt can be represented as a long, straight line of current, what is the magnitude of the magnetic field at a distance of 29 m from the bolt?

    asked on February 11, 2008
  53. science

    tell me about science apparatus They are used in science. You need a much more specific question to get a useful answer. For instance: What is the Hoffman apparatus, and how is it used?

    asked on January 28, 2007
  54. math

    4. A tree stands vertically on top of a hill whose angle of inclination is 30°. The top and base of the tree are 4√3 and 4 meters, respectively, from a point P at the foot of the hill. What is the angle of subtended by the tree at point P?

    asked on February 29, 2016
  55. chemistry

    which metal react most vigorously? metals aluminum, copper, magnesium, lead, tin, zinc 1. which metal will react most quickly? 2. which will take the longest time to react? 3. which will react most vigorously and least vigorously? 4. list metals from order

    asked on April 18, 2013
  56. Pseudocode programming

    I need a currency conversion application. It does not have to be written in an actual programming language, just the pseudocode as well as the elements listed below. Complete requirements analysis Design Verification Validation and test documentation The

    asked on July 24, 2007
  57. math

    a model rocket is projected straight upward from the ground level. It is fired with an initial velocity of 192 ft/s. How high is the rocket after 10 seconds?

    asked on April 9, 2015
  58. Physics

    A man (mass 120.5 kg) is canoeing with his friend (mass 81.6 kg). He had the only paddle but dropped it in the lake. It has drifted just out of his reach along the long axis of the canoe. His friend suggests that if they trade places he might be able to

    asked on October 20, 2014
  59. College Algebra

    Show all work When a person has a cavity filled, the dentist typically administers a local anesthetic. After leaving the dentist's office, one's mouth often feels numb for several hours. If a shot of anesthesia is injected into the bloodstream at the time

    asked on December 1, 2011
  60. history

    What did George Washington and Thomas Jefferson contribute in establishing a stable government after the adoption of the Constitution? For Washington I have: 1) He became first president for 8 years 2) Proclamation of Neutrality protected Americans from

    asked on November 13, 2008
  61. trig

    Prove the identity sin squared 0 with line/2 = csc zero with line -cot zero with a line /2csc zero with a line

    asked on February 28, 2008
  62. physics

    An electron and a proton are initially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.11 10-11m. What is EPEfinal -

    asked on January 30, 2008
  63. geometry

    I was assiged to a 20question assigment and Im having troubles with the following question: "Find the coordinates of the midpoint of a segment having the endpoints C(4,1) and D(-3,7). Then find the distance between the endpoints PLEASE HELP!!! Its due on

    asked on August 24, 2012
  64. Physics

    Force and Motion: A 12 kg armadillo runs onto a large pond of level, frictionless ice. The armadillo's initial velocity is 5m/s along the positive direction of the x-axis. Take its initial position on the ice as being the origin. It slips over the ice

    asked on July 7, 2010
  65. Physics

    Vector A has a magnitude 12m and is angled at 60 degrees counterclockwise from the positive direction of the x axis of an xy coord. system. Also. Vector B = (12m)i + (8m)j on that same coord system. Rotate the system counterclockwise about the origin by 20

    asked on June 27, 2010
  66. psychology

    Much research is being conducted on repairing faulty sensory organs through devices such as personal guidance systems and eyeglasses, among others. Do you think that researchers should attempt to improve normal sensory capabilities beyond their

    asked on May 13, 2014
  67. marketing

    The marketing manager at Massimino & McCarthy, a chain of retail stores that sells men's clothing, is reviewing marketing research data to try to determine if changes in marketing strategy are needed. Which of the following sources of data would be a

    asked on May 30, 2013
  68. Algebra

    Find a linear equation whose graph is the straight line with the given property. HINT [See Example 2.] Through (2, −3) and (1, 1) Which formula do I use? y2-y1/x2-x1 or y-y1=m(x-x1)[

    asked on February 19, 2012
  69. math

    solve each triangle using either the Law of Sines or the Law of Cosines. If no triangle exists, write “no solution.” Round your answers to the nearest tenth. A = 23°, B = 55°, b = 9 A = 18°, a = 25, b = 18

    asked on December 9, 2011
  70. math

    Circla all numbers in which the ones digit is twice the hundreds digit. 842 824 482 284 248 933 977 337 379

    asked on November 18, 2010
  71. algebra

    One day a store sold 45 pens, the zippedy do's at $8.50 & The Royal Blues at $9.75. In all, $398.75 was spent on the pens. How many Royal Blues were sold that day?

    asked on September 30, 2010
  72. physics

    From a distance of 60 m, a photographer uses a telephoto lens (f = 300.0 mm) to take a picture of a charging rhinoceros. How far from the rhinoceros would the photographer have to be to record an image of the same size using a lens whose focal length is

    asked on March 24, 2008
  73. trig

    Prove the identity sin(3 pi /2 + x) + sin(3pi/2 -x) = -2cosx

    asked on February 28, 2008
  74. physics

    There is a 0.225 T magnetic field directed along the +x axis and a field of unknown magnitude along the +y axis. A particle carrying a charge of 7.20 10-5 C experiences a maximum force of 0.455 N when traveling at a speed of 2 104 m/s through the region

    asked on February 10, 2008
  75. physics

    A toaster uses a Nichrome heating wire. When the toaster is turned on at 20°C, the initial current is 1.50 A. A few seconds later, the toaster warms up and the current has a value of 1.22 A. The average temperature coefficient of resistivity for Nichrome

    asked on January 30, 2008
  76. Maths

    Two ships sail from port P. One sails 14km due south while the other sails 17km on a bearing of 120 degrees. Calculate to one decimal place the distance between the ships.

    asked on November 2, 2017
  77. Maths

    The training of a football team involves running up and down a sandhill 25 times. If the hill is 30 m high and inclined at an angle of 35 degrees to the horizontal, how far does the team run during the training? Answer to the nearest 0.1 km.

    asked on September 22, 2017
  78. health

    Which of the following is NOT a type of muscle? A. Skeletal B. Long C. Smooth D. Cardiac

    asked on August 18, 2016
  79. math

    Pat worked 43 hours and received $7.25 per hour for regular pay and time-and-a-half for all hours over 40 hours. What were her weekly earnings?

    asked on September 24, 2015
  80. Chemistry

    10. For the titration of 20.00 mL 0.1000 M lactic acid with 0.1000 M NaOH, calculate the pH: a. before any titrant is added b. 10.00 mL prior to the equivalent point c. at the equivalent point d. 10.00 mL after the equivalence point. Plot the points

    asked on June 22, 2014
  81. geometry

    I'm stuck on this question please help. "GK bisects angle FGH". If angle FGK=8v-2 and angle KGH=3v+3,find angle FGH. PLEASE HELP ME

    asked on August 28, 2012
  82. math

    Solve the following polynomial inequalities. A) x^3 - 5x^2 + 2x ≥ -8 B)2(x3 - 2x2 + 3) < x(x - 1)(x + 1)

    asked on May 10, 2012
  83. chemistry

    A 114g sample of sucrose undergoes incomplete combustion according to the reaction C12H22011 + 5O2 ---> 4C + 6CO + 2CO2 + 11H2O using the chart of enthalpies of formation determine the enthalpy released by the sample i think that it is a simple enthalpy

    asked on July 25, 2010
  84. ushistory

    the assembly line production of henry ford's model t automobile resulted in what? my answer: it resulted in development of a large interantional marekt for american automobiles but im not sure if it was a sharp decrese in railroad passenger traffic or a

    asked on November 28, 2009
  85. physics

    An electron and a positron each have a mass of 9.11*10^-31 kg. They collide and both vanish, with only electromagnetic radiation appearing after the collision. If each particle is moving at a speed of 0.55c relative to the laboratory before the collision,

    asked on April 15, 2008
  86. physics

    A camera is supplied with two interchangeable lenses, whose focal lengths are 35.0 and 150.0 mm. A woman whose height is 1.80 m stands 7.00 m in front of the camera. What is the height (including sign) of her image on the film, as produced by (a) the

    asked on March 24, 2008
  87. Math permutations

    pi=(245)(1354)(125) 1) Write as a product of disjoint cycles. Ans: (14)(253) Is this correct? 2) Solve : pi^2, pi^5,pi^(-1) 3) What's the order of pi? and why?

    asked on November 24, 2007
  88. Physics

    A space probe has two engines. Each generates the same amount of force when fired, and the directions of these forces can be independently adjusted. When the engines are fired simultaneously and each applies its force in the same direction, the probe,

    asked on February 12, 2014
  89. physics

    A ball is thrown 107 m upward and then falls back to earth. Neglecting air resistance, how long will it be in the air? The acceleration of gravity is 9.8 m/s2 . Answer in units of s

    asked on October 5, 2013
  90. Economics

    I have a few questions, for my test coming up. Which of the following is most necessary for specialization among producers to take place? Free trade Monetary policy Competition Scarcity Which of the following best states the purpose of an import quota? To

    asked on March 13, 2012
  91. investment

    publicly-owned stock that is not listed on an exchange is traded in the over-the counter markets such as that Nasdap stock market, true or false. systematic risk is reduce through diversification is true or false unsystematic risk considerrs how firms

    asked on September 30, 2011
  92. Physics

    an object of mass 3 kg is moving in the positive x-direction with a speed of 10 m/s. A second object of mass 5 kg is moving in the northwest direction with a speed of 8 m/s. If the two stick together after the collision, what is the final velocity

    asked on June 29, 2011
  93. physics

    The average emf induced in the secondary coil is 0.10 V when the current in the primary coil changes from 3.2 to 2.0 A in 0.10 s. What is the mutual inductance of the coils?

    asked on February 13, 2008
  94. Physics

    A boy with a mass of 40kg is seated a distance of 3.0m from the fulcrum of a seesaw. a. Calculate the load force exerted by the boy (Hint: What force is pulling him down?) b. Calculate the torque exerted by the boy. c. If his sister with a mass of 24 kg

    asked on April 28, 2016
  95. algebra

    Draw a rectangle to show that 5 (x + 2 ) and 5x + 10 are equivalent ?

    asked on January 4, 2016
  96. Physics Help..

    The cable of an elevator of mass M = 1900 kg snaps when the elevator is at rest at one of the floors of a skyscraper. At this point the elevator is a distance d = 10.6 m above a cushioning spring whose spring constant is k = 8500 N/m. A safety device

    asked on December 30, 2013
  97. Algebra

    A goldsmith has two gold alloys. The first alloy is 20% gold; the second alloy is 60% gold. How many grams of each should be mixed to produce 40 grams of an alloy that is 30% gold? amount of 20% gold_____g Amount of 60% gold_____g

    asked on June 1, 2013
  98. math

    Two similar rectangular gardens have a ratio of 2:3. If one side of the larger garden is 18 feet, how long is the corresponding side of the smaller garden?

    asked on January 30, 2013
  99. geometry

    I"m stuck on this question "Rays PQ and QR ae perpendicular.Point S lies in the interior of angle PQR.If angle PQS!=4+7a and angle SQR=9+4a,find angle PQS and angle SQR. PLEASE HELP!!!!

    asked on August 25, 2012
  100. math

    At noon, ship A is 50 nautical miles due west of ship B. Ship A is sailing west at 16 knots and ship B is sailing north at 21 knots. How fast (in knots) is the distance between the ships changing at 3 PM

    asked on November 5, 2010


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