Most popular questions and responses by Danny
  1. Physical Science

    Energy from the sun reaches Earth mostly by A. conduction. B. convection. C. radiation. D. thermal expansion. I think it's A.

    asked on September 3, 2013
  2. Chemistry

    The equation for the complete combustion of ethene (C2H4) is C2H4(g) + 3 O2(g) ==> 2CO2(g) + 2H2O(g) If 2.70 mol C2H4 is reacted with 6.30 mole O2, identify the limiting reagent. show all work.

    asked on March 27, 2010
  3. Chemistry

    What is the symbol for an ion with 63 protons, 60 electrons, and 88 neutrons? If an ion contains 50 protons, 68 neutrons, and 48 electrons, what is its symbol? Please help me.. im soo lost in this problem!

    asked on July 24, 2008
  4. Algebra 2

    Amanda surveyed 20 juniors and seniors at Delamar high school to find the number of hours per week they spend working at part-time jobs. Her results are shown below. Juniors: 20,10,20,10,15,0,0,10,20,15 Seniors: 20,20,10,10,0,0,0,10,0,10 which statement

    asked on May 19, 2014
  5. chemistry

    Given: Equation #1: 4NH3(g) + 5O2(g) = 4NO(g) + 6H2O; ΔH of reaction = -1170 kJ Equation #2: 4NH3(g) + 3O2(g) = 2N2(g) + 6H2O; ΔH of reaction = -1530 kJ Then what is the ΔH of reaction for: N2(g) + O2(g) = 2NO(g)? Enter a numerical value below and be

    asked on January 31, 2015
  6. Physics

    A merry-go-round is a common piece of playground equipment. A 2.4 m diameter merry-go-round with a mass of 300 kg is spinning at 22 rpm. John runs tangent to the merry-go-round at 5.0 m/s, in the same direction that it is turning, and jumps onto the outer

    asked on December 2, 2011
  7. Algebra 1

    a farmer raises chickens and cows. there are 34 animals in all. the farmer counts 110 legs total on these animals. how many chickens and how many cows are on this farm?

    asked on May 16, 2011
  8. Calculus. I need help!

    Write the composite function in the form f(g(x)). [Identify the inner function u=g(x) and the outer function y=f(u).] Then find the derivative dy/dx. y=√sinx √ is square root.

    asked on February 25, 2012
  9. Economics Macro

    Suppose that real GDP per capita in the United States is $49,000. If the long-term growth rate of real GDP per capita is 1.6% per year, how many years will it take for real GDP per capita to reach $98,000?

    asked on January 25, 2016
  10. Chemistry

    As a sample of the radioactive isotope 131 I decays, its half-life a)decreases b)increases c)remains the same

    asked on May 5, 2010
  11. chemistry

    What is the approximate effective nuclear charge for arsenic ?

    asked on April 27, 2015
  12. chemistry

    The enthalpy change for the following reaction is -483.6 kJ: 2H2(g) + O2(g) = 2H2O(g) Therefore, the enthalpy change for the following reaction is _______ kJ: 4H2(g) + 2O2(g) = 4H2O(g)

    asked on January 31, 2015
  13. History

    What time of year does snow come to the far north?

    asked on January 21, 2015
  14. Physics (Stress & Strain)

    A hole 3cm in diameter is to be punched out of a steel plate 8cm thick. The shear stress of the material is 670GPa. What load is required on the punch? 3cm = 0.03m 8cm = 0.08m Lateral surface area (As) = pi*D*h = 3.1416 * .03m * .08m = 3.1416 * .0024m =

    asked on June 26, 2013
  15. chemistry

    How many calories are required to heat 25.0 g of platinum from 24.5 °C to 75°C (specific heat of platinum = 0.139 J/gK)? 1. 47 cal 2. 42 cal 3. 48 cal 4. 20 cal 5. 80 cal Thank you.

    asked on November 22, 2009
  16. physics

    A highway curve with radius 1000ft is to be banked so that a car traveling 56.0mph will not skid sideways even in the absence of friction At what angle should the curve be banked?

    asked on March 9, 2015
  17. physics

    A 55 kg hiker starts at an elevation of 1600 m and climbs to the top of a 3400 m peak. (a) What is the hiker's change in potential energy?

    asked on July 9, 2012
  18. physics

    21. A traffic signal of mass 25.0 kg is suspended by two cables as shown in the diagram below. Solve for the tension in each cable each of the following scenarios: (a) θ1 = θ2 = 20.0°, and (b) θ1 = 20.0°, θ2 = 30.0°.

    asked on February 17, 2015
  19. Chemistry

    How many mL of 0.225M HCl would be required to titrate 6.00 grams of KOH?

    asked on March 25, 2010
  20. chemistry

    Is the dissolution of borax in water a temperature dependent reaction or is it spontaneous at all temperatures at which water is liquid? I think its spontaneous at all temperatures when water is liquid because borax is a polar compound.

    asked on April 1, 2008
  21. Chemistry

    Identify the solvent and the solute in vinegar, a dilute aqueous solution of acetic acid.

    asked on April 13, 2010
  22. Physical Science

    The Magnetic field lines of a bar magnet begin near the magnet's _____________. I believe this question is asking where the lines begin (ie leave) the bar magnet...which would be the north pole.

    asked on September 4, 2013
  23. English 3

    Young Goodman Brown is a dynamic character TRUE OR FALSE

    asked on November 7, 2012
  24. Physics

    Simple Machines A simple wheel and axle has a wheel diameter of 2.3m and an axle diameter of 92mm. If an effort of 26N is required to raise a mass of 16 kg what is the efficiency of the machine? A- 2.46% B- 95.3% C- 24.1% D- 20.1% E- 65.5% I am having a

    asked on May 11, 2013
  25. Physics

    The "Screaming Swing" is a carnival ride that is-not surprisingly-a giant swing. It's actually two swings moving in opposite directions. At the bottom of its arc, riders are moving at 30 m/s with respect to the ground in a 44 m-diameter circle. At the

    asked on September 27, 2010
  26. Physics

    Richard is driving home to visit his parents. 125 of the trip are on the interstate highway where the speed limit is 65 . Normally Richard drives at the speed limit, but today he is running late and decides to take his chances by driving at 70. How many

    asked on September 16, 2010
  27. Physics

    The "Screaming Swing" is a carnival ride that is-not surprisingly-a giant swing. It's actually two swings moving in opposite directions. At the bottom of its arc, riders are moving at 30 m/s with respect to the ground in a 44 m-diameter circle. At the

    asked on September 27, 2010
  28. chemistry

    In the reaction below, ΔH°f is zero for ___________. Ni(s) + 2CO(g) + 2PF3(g) = Ni(CO)2(PF3)2(l) Ni(s) CO(g) Ni(CO)2(PF3)2(l) both CO(g) and PF3(g) PF3(g)

    asked on January 31, 2015
  29. chemistry

    At a certain elevation, the boiling point of water is 98.5°C. How much energy is needed to heat 35.0 mL of water to the boiling point at this elevation if the water initially was at 23.4°C? (Cp=75.38J/(mol*C), d= 1.00g/mL)

    asked on April 1, 2015
  30. chemistry

    Consider an electrochemical cell based on the reaction: 2H+(aq) + Sn(s) = Sn2+(aq) + H2(g). Which of the following actions would NOT change the measured cell potential? lowering the pH in the cathode compartment addition of more tin metal to the anode

    asked on April 19, 2015
  31. grammar

    Which part of speech is the capitalized words in this sentence? Four score and seven years ago our fathers brought forth on this continent, a NEW nation, conceived in Liberty, and DEDICATED to the proposition that all men are created equal. Now we are

    asked on November 17, 2013
  32. english

    "The editors . . . break those sequences up into quick jagged shots that key us up and keep us hyper-alert . . . we look hard at the screen to take it in." universality?

    asked on October 29, 2010
  33. Chemistry

    A sprinter must average 24.0 mi/h to win a 100-m dash in 9.30 s. What is his wavelength at this speed if his mass is 84.5 kg?

    asked on October 5, 2014
  34. global

    Why would so many women miners prefer to work in the mines without clothing? Why did the women need the heavy belts around their waists and chains between their legs?

    asked on February 24, 2010
  35. Chemistry

    Consider the following reaction. 2Fe2O3 --> 4Fe+3O2 Hrxn=+824.2 The Formation of 21.0 of Fe results in 1)the release of 77.5 kJ of heat. 2)the absorption of 3.10 × 102 kJ of heat. 3)the release of 4330 kJ of heat. 4)the absorption of 77.5 kJ of heat.

    asked on October 30, 2016
  36. physics

    A typical multivitamin tablet can contain 2.00mg of vitamin B2 (riboflavin), and the RDA is 0.0030 g/day. How many such tablets should a person take each day to get the proper amount of this vitamin, assuming that he gets none from any other sources?

    asked on January 28, 2015
  37. english

    "He manages to portray tiny, random events as significant without the occasionally overblown melodrama . . . " so im suppose to Read the quote and choose its category. but i don't no what to do? these are my answer choices.. -universality -subject matter

    asked on October 28, 2010
  38. physics

    A locomotive is accelerating at 2.0 m/s2. It passes through a 20.0-m-wide crossing in a time of 2.8 s. After the locomotive leaves the crossing, how much time is required until its speed reaches 36 m/s?

    asked on September 10, 2011
  39. statistics

    A regression analysis between sales (in $1000) and advertising (in $100) resulted in the following least squares line: = 75 + 6x. This implies that if advertising is $800, then the predicted amount of sales (in dollars) is: A) $4875 B) $123,000 C) $487,500

    asked on August 18, 2009
  40. chemistry

    How many electrons does the Au+ ion have ? Enter an integer below without any letters or symbols.

    asked on April 15, 2015
  41. math

    Two similar polygons have areas of 16 square inches and 64 square inches. The ratio of a pair of corresponding sides is 1/4. True False its true?

    asked on April 6, 2011
  42. englsih

    Expanding the Canon . . . tends to drive out the better writers, sometimes even the best, because pragmatically none of us (whoever we are) ever had time to read absolutely everything . . . inadequate authors will consume the energies that would be better

    asked on October 28, 2010

    Calculate the pH at the equivalence point in titrating 0.100 M solutions of each of the following with 0.080 M NaOH. a)hydrobromic acid (HBr) b)chlorous acid (HClO2) c)benzoic acid (C6H5COOH)

    asked on February 29, 2012
  44. physics

    A 100-kg crate, sliding on the floor, is brought to a stop by a 25-n force. What is the deceleration of the crate?

    asked on March 20, 2009
  45. english

    What type of literary or dramatic works did William Shakespeare write? burlesque pantomime satire Restoration comedy heroic drama Elizabethan drama autobiography

    asked on November 18, 2010
  46. math

    A steel tube has an outside diameter of 15 cm, an inside diameter of 13 cm,and is 3.7 m long. What is the volume of the steel contained in the tube in cubic cm is?

    asked on April 19, 2013
  47. Stress & Strain (Help Please)

    A tie bar is made of a material having a tensile strength of 231 MPa and has to carry a load of 255 kN. What id the diameter of the bar if a factor of safety of 7 is applied? ANS = 99.2 mm Cannot figure out how to get the answer. Need help please. Thank

    asked on August 10, 2013
  48. chemistry

    The combustion reaction of acetylene gas is represented by this equation: 2C2H2(g) + 5 O2(g) ==> 4CO2(g) + 2H2O(g) How many grams of CO2 and grams of H2O are produced when 52.0g C2H2 burns in oxygen?

    asked on March 22, 2010
  49. math

    The only defined term of those listed is: line angle plane point

    asked on April 13, 2011
  50. Chemistry

    In a 0.05M solution of a weak monoprotic acid,[H+]=.0018.What is its Ka?

    asked on April 27, 2012
  51. Chemistry

    5F2(g) + 2NH3(g) ==> N2F4(g) + 6HF(g) a)If you have 66.6 g NH3, how many grams of F2 are required for complete reaction? b)How many grams of NH3 are required to produce 4.65g HF? c)How many grams of N2F4 can be produced from 225g F2?

    asked on April 5, 2010
  52. chemistry

    Which element is reduced in the unbalanced reaction below? I− + MnO4− + H+ = I2 + MnO2 + H2O I no reduction occurred in this reaction O H Mn

    asked on April 16, 2015
  53. Chemistry

    Why is methanol a good solvent to recrystallize biphenyl?

    asked on February 25, 2016
  54. Physics

    A 225-kg crate is pushed horizontally with a force of 690 N. If the coefficient of friction is 0.20, calculate the acceleration of the crate.

    asked on November 17, 2012
  55. Chemistry

    Magnesium reacts with oxygen to form magnesium oxide according to the following equation: 2Mg(s) + O2(g) ==> 2MGO(s) If 0.81 grams of magnesium oxide are formed, how many grams of oxygen reacted?

    asked on May 5, 2010
  56. Trig

    the graph of an inverse trigonometric function passes through the point (1,pi/2). which of the following could be the equation of the function Y=Cos^-1 x Y=cot^-1 x Y=Sin^-1 x Y=Tan^-1 x

    asked on March 6, 2018
  57. Pre-Calculus

    A hemispherical bowl with a 30-centimeter radius contains some water, which is 12 centimeters deep. Find the volume of the water.

    asked on October 10, 2016
  58. Optics

    The famous Chinese magician Foo Ling Yu performs a classic magic trick using a concave mirror with a focal length of 1.6 m. Foo uses the mirror to produce an image of a light bulb that is the same size as the light bulb itself and is at the same location.

    asked on June 5, 2018
  59. science

    A 5.0 kg model vehicle travelling at 14 m/s experiences a rocket boost of 85 N ( in the direction of motion) for 20 s What is the resulting speed? The answer is 350 but i don't know how to get to that answer

    asked on November 6, 2014
  60. Physical Science

    If no friction acts on a diver during a dive, then which of the following statements is true? A. The total mechanical energy of the system increases. B. Potential energy can be converted into kinetic energy but not vice versa. C. (KE+ PE)beginning = (KE +

    asked on September 3, 2013
  61. Math

    Radio stations use three or four letters for their call letters(name). The first letter must be a W or K. How many different call letters are possible if repeated letters are allowed? And not allowed?

    asked on March 29, 2013
  62. physics

    Early skeptics of the idea of a rotating Earth said that the fast spin of Earth would throw people at the equator into space. The radius of Earth is about 6400 km. Show why this objection is wrong by determining the following information. (a) Calculate the

    asked on December 6, 2012
  63. chemistry

    One of the ways to produce iron is to take iron(II) oxide and react it with carbon monoxide to get pure iron and carbon dioxide. The reaction is FeO(s) + CO(g) = Fe(s) + CO2(g). What is the partial pressure of CO2(g) if 2.00 atm of CO and excess iron(II)

    asked on February 28, 2015
  64. gen chem

    The recommended dosage of iodine-131 is uCi/kg of body weight. How many microcuries of iodine-131 are needed for a patient with the hyperthyroidism?

    asked on June 10, 2012
  65. chemistry

    Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) gas and calcium hydroxide (Ca(OH)2). If the ΔH for: CaC2(s) + 2H2O(l) = Ca(OH)2(s) + C2H2(g) is -127 kJ, then what is the enthalpy of formation for calcium carbide? The ΔH of formation for

    asked on January 31, 2015
  66. chem

    If you burn 13.7 g of methane (CH4) burns in oxygen, then 686 kJ is evolved. What is the amount of heat produced per mole of methane burned?

    asked on January 27, 2015
  67. calculus

    Imagine making a tent in the shape of a right prism whose cross-section is an equilateral triangle (the door is on one of the triangular ends). Assume we want the volume to be 2.2 m3, to sleep two or three people. The floor of the tent is cheaper material

    asked on December 10, 2013
  68. Math

    Frank has 3 nickels, 5 dimes, and 2 quarters. What is the range, mean, median, and mode of the values of Frank's coins?

    asked on March 18, 2013
  69. Religion

    What countries of origin Hinduism, Buddhism, Confucianism and Daoism? What are historical figures and events Hinduism, Buddhism, Confucianism and Daoism? What are the central beliefs of Hinduism, Buddhism, Confucianism and Daoism? The nature of god of

    asked on January 13, 2008
  70. math

    If the radius of this cylinder is doubled, its volume will be twice as much four times as much eight times as much is it four times as much?

    asked on April 4, 2011
  71. scte

    a 90 volt Hz source is connected to 0.1 Henry inductor.what is the current through the inductor?

    asked on April 26, 2016
  72. Physics

    One gram of palladium has 5.66×10^21 atoms, and each palladium atom has 46 electrons. How many electrons are contained in 7.00g of palladium? The elemental charge is1.6×10^−19C. Answer in units of electrons. The answer is 1.82252x10^24 for Part A. i

    asked on February 8, 2015
  73. Velocity

    An object is thrown directly downwards from a height of 60m with an initial velocity of 11m/s. What will be its velocity on impact? v^2 = U^2 + 2as a= 9.81m/s^2 u = 11m/s s = 60m v^2 = 11m/s + 2 * 9.81m/s^2 * 60 = 1188.2m^2/s^2 = square root of

    asked on June 3, 2013
  74. english

    Which of the following topics relate directly to a work's authenticity? 1)believability of characters 2)the appeal of a certain guitar riff 3)sincerity expressed in a love song 4)the likely appeal to all teenagers 5)the way the setting matches the mood of

    asked on November 1, 2010
  75. english

    When the theaters reopened, the age of Restoration drama began. true?

    asked on November 11, 2010
  76. Physic

    A 2.2 m-long string is fixed at both ends and tightened until the wave speed is 50 m/s. What is the frequency of the standing wave shown in the figure? Answer in Hz. I've been working on it for a while but cant figure out...

    asked on November 7, 2009
  77. chemistry

    ΔS is positive for which one of the following reactions? Ag+(aq) + Cl- (aq) = AgCl(s) N2(g) + 3H2(g) = 2NH3(g) CaO(s) + CO2(g) = CaCO3(s) 2SO3(g) = 2SO2(g) + O2(g) H2O(l) = H2O(s)

    asked on February 7, 2015
  78. math

    When chords intersect in a circle, the vertical angles formed intercept congruent arcs. always sometimes never

    asked on January 6, 2011
  79. Chemistry

    Laughing gas (nitrous oxide, N2O) is sometimes used as an anesthetic in dentistry. It is produced when ammonium nitrate is decomposed according to the reaction NH4NO3(s) −! N2O(g) + 2H2O(§¤) . How much NH4NO3 is required to produce 54.5 g of N2O?

    asked on April 9, 2015
  80. LO

    a newspaper article to warn people against engaging with fraud

    asked on April 24, 2016
  81. Physics

    A train traveling at a speed of 110 km/h uniformly decelerates for 20 seconds. During that time it travels 450m. A) What is the acceleration? (m/s^2) B) What is its speed after deceleration? (km/h) A ANS = -.805m/s^2 B ANS = 52km s = 450m t = 20 seconds u

    asked on January 11, 2014
  82. chemistry

    The Ka of hypochlorous acid (HClO) is 3.00×10-8 at 25.0°C. Calculate the pH of a 0.0385 M hypochlorous acid solution. a.1.41 b.7.52 c.-1.41 D.4.47 E. 8.94 I got B 7.52 but i feel like im wrong

    asked on March 21, 2015
  83. physics

    In college softball, the distance from the pitcher's mound to the batter is 43 feet. If the ball leaves the bat at 90 , how much time elapses between the hit and the ball reaching the pitcher?

    asked on September 16, 2010
  84. geography

    did the french ever go down to mexico with the spanish

    asked on June 11, 2019
  85. Chemistry

    What is the pH of a 0.200M solution for HBrO? Ka = 2.8 x 10^-9

    asked on March 25, 2010
  86. Physics (Stress & Strain)

    A uniform bar 1.900 meters in length and having a cross sectional area of 11.000cm^2 is subject to a loading of 5450.000 Newtons. this load causes an extension to the bar length of 2.420mm. Calculate the stress and strain produced. 11cm = .11m 2.420mm =

    asked on June 26, 2013
  87. Physics

    If the specific volume of red brass is 0.001865 ft/3lb. What would be the density? Thanks!

    asked on February 1, 2013
  88. physics

    The block of mass 1.43443 kg has an acceleration of 3.6 m/s^2 as shown. What is the magnitude of F? Assume the acceleration due to gravity is 9.8 m/s^2 and the surface is frictionles

    asked on November 13, 2014
  89. Spanish

    ¿Con quién _____ tú el almuerzo? A. comparto B. compartes C. compartimos D. comparte B?

    asked on September 16, 2013
  90. Physics

    One of the most powerful cranes in the world, operating in Switzerland, can slowly raise a load of 6000 tonne to a height of 12 m. (1 tonne = 1000 kg) The acceleration of gravity is 9.81 m/s2 . How much work is done by the crane? Answer in units of MJ I

    asked on February 26, 2013
  91. 4th grade math

    I have to make a table or list to solve these problems. 1. Tina and Bruce are each rolling a 1 to 6 number cube. They are looking for different ways to roll two factors whose product is greater than 14. How many different ways will they find? 2. Trenton

    asked on September 10, 2013
  92. Physical Science

    The primary colors of pigments A. are cyan, yellow, and magenta. B. are the same as the secondary colors of light. C. combine in equal amounts to produce black. D. all of the above I think it's D.

    asked on September 4, 2013
  93. Calculus Physics

    Imagine a spaceship on its way to the moon from the earth. Find the point, as measured from the center of the earth, where the force of gravity due to the earth is balanced exactly by the gravity of the moon. This point lies on a line between the centers

    asked on March 2, 2015
  94. science

    Zinc chloride solution is poured into a solution of ammonium carbonate. need conventional, ionic and net ionic equations thanks

    asked on March 12, 2013
  95. math


    asked on June 11, 2019
  96. college algebra

    An open box is made from a square piece of cardboard 20 inches on a side by cutting identical squares from the corners and turning up the sides.(a) Express the volume of the box, V , as a function of the length of the side of the square cut from each

    asked on September 27, 2012
  97. Calculus Physics

    A glass of orange juice is on the floor of a subway car traveling along a straight path at constant velocity. Everything's fine. The coefficient of static friction between the glass and the floor is 0.32. The subway suddenly accelerates forward. What is

    asked on March 2, 2015
  98. chemistry

    The activation energy of a reaction is typically determined by calculating the rate constant for the reaction at two temperatures and then manipulating the Arrhenius equation. If you determine the reaction rate constants for a particular reaction to be

    asked on February 14, 2015
  99. Physics

    a 47 kg person in a rollercoaster moving through the bottom of a curved track of radius 47.7 m feels a normal force of 895 N. What is the net centripedal force acting on the person

    asked on June 13, 2019
  100. Math Trigonometry

    A plane flies in a direction of 85° from Chicago. It then turns and flies in the direction of 200° for 150 miles. It is then 195 miles from its starting point. How far did the plane fly in the direction of 85°? I am confused about aereal navigation. Can

    asked on May 19, 2016


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