Popular questions and responses by luke
  1. math

    what is the answer to the math pizzazz E-30? What is the title?

    asked on December 9, 2013
  2. probability

    consider a sequence of independent tosses of a biased coin at times k=0,1,2,…,n. On each toss, the probability of Heads is p, and the probability of Tails is 1−p. A reward of one unit is given at time k, for k∈{1,2,…,n}, if the toss at time k

    asked on February 27, 2014
  3. math

    how does a rodeo star get around?

    asked on March 2, 2016
  4. Chemistry

    Use an enthalpy diagram to calculate the lattice energy of CaCl2 from the following information. Energy needed to vaporize one mole of Ca(s) is 192 kJ. For calcium, the first IE = 589.5 kJ mol-1, the second IE = 1146 kJ mol-1. The electron affinity of Cl

    asked on June 29, 2014
  5. English

    How does the boldness Odysseus shows in the Cyclops’s cave drive subsequent plot events? A)Several of Odysseus’s men are eaten. B)Odysseus and his men spend the night in the Cyclops’s cave. C)Odysseus gives the Cyclops wine to drink. D)Odysseus and

    asked on May 19, 2016
  6. Math

    And angle measures 53° what are the measures of the angles complement and supplement a complement 37° supplement 137° be complement 127° supplement 47° C complement 37° supplement 127° D complement 127° supplement 37° my answer is B is that right

    asked on February 4, 2019
  7. physics

    a remote controlled car's wheel accelerates at 22.4 rad/s^2. if the wheel begins with an angular speed of 10.8 rad/s what is the wheel's angular speed after exactly 3 full turns?

    asked on February 12, 2009
  8. Physics

    While following the directions on a treasure map, a pirate walks 36.6 m north, then turns and walks 6.3 m east. A.) What is the magnitude of the single straight-line displacement that the pirate could have taken to reach the treasure? Answer in units of m.

    asked on November 8, 2012
  9. science

    Which physical properties are characteristics of metals? Choose all that apply. -brittle -high luster -malleable -ductile -not very reactive 1, 2, and 5?

    asked on September 24, 2015
  10. chem

    Which statement is wrong? 1. Adding the same amount of heat to two different objects will produce the same increase in temperature. 2. When the same amount of heat produces different changes in temperature in two substances of the same mass, we say that

    asked on April 25, 2012
  11. Chem

    How much methane, in grams, must be burned to release 542 kJ of heat? H=-802kJ

    asked on June 26, 2014
  12. math

    a spinner wheel with 3 color choices red, blue, and yellow) is spun and a 4 sided die I rolled. list the possible outcomes described in the situation.

    asked on February 2, 2018
  13. physics

    A shell fired from the ground with an initial speed of 1.70 x 10^3 m/s at an initial angle of 55 degrees to the horizontal. neglecting air resistance, find a) the shell's horizontal range b)the amount of time the shell is in motion.

    asked on November 6, 2010
  14. Calculus

    find d^2y/dx^2 (second derivative) for y=cos^2 4x

    asked on October 21, 2011
  15. english essay

    The second poem I will write about is ‘the conscript’ it was written by Wilfred Gibson in 1917. a law was passed to force men to join up between the ages of 18-41 unless they were ill this poems says what you’re really going to expect from the war if

    asked on March 6, 2013
  16. Math

    The measure of angle a is 124° what is the correct classification for angle a is it Acute right obtuse straight

    asked on February 4, 2019
  17. vectors

    Express the unit vectors iˆ, jˆ, and kˆ as ordered triples and show that: a) iˆ x jˆ = kˆ b) kˆ x jˆ = -iˆ To begin, I subbed in iˆ= (1,0,0) jˆ= (0,1,0) kˆ = (0,0,1) for a) I got (0,-1,1) = (0,0,1) after crossing i x j What do I do next?

    asked on May 27, 2018
  18. chemistry

    a metal sample weighing 45.0g and at a temperature of 99.1C was place in 38.6g of water in a calorimeter at 25.0C. the calorimeter reached a maximum temperature of 32.8C. 1. calculate the specific heat of the metal. 2. what is the approximate molar mass of

    asked on November 13, 2008
  19. chemistry

    Aqueous solutions of iron (III) sulphate and barium hydroxide are combined. Does a precipitate form? If yes write a net ionic equation for the precipitation reaction. You first identify the formula of the aqueous compounds (note that iron is said to be

    asked on November 13, 2011
  20. Vectors

    A boat heads 15 degrees west of north with a water speed of 3 m/s. Determine its velocity relative to the ground when there is a 2 m/s current from 40 degrees east of north.

    asked on May 25, 2018
  21. chemistry

    Suppose that the microwave radiation has a wavelength of 12 cm . How many photons are required to heat 295 mL of coffee from 25.0 ∘C to 62.0 ∘C? Assume that the coffee has the same density, 0.997 g/mL , and specific heat capacity, 4.184 J/(g⋅K) , as

    asked on June 9, 2019
  22. math

    Find (A upside down U B) upside down U C, given A = {s,e,t} B = {m,E} C = {f,r,e,e,}

    asked on August 18, 2010
  23. Geometry

    How do you divide a hexagon into 9 congruent parts?

    asked on October 3, 2007
  24. Physics

    In a common test for cardiac function (the "stress test"), the patient walks on an inclined treadmill (Figure 6-46). Estimate the power required from a 70 kg patient when the treadmill is sloping at an angle of 15° and the velocity is 3.10 km/h.

    asked on February 16, 2013
  25. Statistics

    A roulette wheel has 38 slots, numbered 0, 00, and 1 to 36. Two slots are green, 18 of the others are red, and 18 are black. a) What is the probability of winning with a bet on red in a single play of roulette? b) You decide to play roulette 4 times, each

    asked on June 7, 2015
  26. Physics

    Two buckets of sand hang from opposite ends of a rope that passes over an ideal pulley. One bucket is full and weighs 110 N ; the other bucket is only partly filled and weighs 65 N . You release the lighter bucket and the heavier one descends. What is the

    asked on November 8, 2015
  27. science

    which kind of inclined plane pushes up more steeper or flatter? what do you think causes this?

    asked on February 24, 2020
  28. math

    5.6 lb/gal = oz/gal

    asked on December 13, 2014
  29. chemistry

    What happens to the concentration of SO2(g) when the total pressure on the equilibrium reaction 2 SO2(g) + O2(g) 2 SO3(g) is increased (by compression)? I thought it remained the same but that was incorrect.

    asked on April 3, 2012
  30. Maths

    Make h subject of formula in A=πr√h²-r²

    asked on February 17, 2017
  31. chemistry

    1. Silicon dioxide reacts with carbon upon heating to produce silicon carbide (SiC) and carbon monoxide. SiO2(s) + 3C(s) = SiC(s) + 2CO(g) a. What mass of carbon is required to react completely with 15.70 g of SiO2? b. When 152 g of SiO2 reacts with excess

    asked on December 13, 2016
  32. chemistry

    FeSO4 (aq) + Ba(OH)2 (aq) = BaSO4 (s) + Fe(OH)2 (s) 2Fe3+(aq) + 3SO4=(aq) + 3Ba2+(aq) + 6OH-(aq) ===> 2Fe(OH)3(s) + 3BaSO4(s) which one respresents the precipate when iron (III) sulphate aq and barium hydroxide aq are combined.

    asked on November 13, 2011
  33. physics

    Suzie (of mass 76 kg) is roller-blading down the sidewalk going 12 miles per hour. She notices a group of workers down the walkway who have unexpectedly blocked her path, and she makes a quick stop in 1.9 seconds. What is Suzie’s average acceleration

    asked on October 10, 2013
  34. chem

    For the gaseous equilibrium represented below, it is observed that greater amounts of PCl3 and Cl2 are produced as the temperature is increased. PCl5(g) PCl3(g) + Cl2(g) a) What is the sign of S° for the reaction? Explain. b) What change, if any, will

    asked on April 29, 2008
  35. Chemistry

    A saturated solution is made by dissolving 0.252 g of a polypeptide (a substance formed by joining together in a chainlike fashion some number of amino acids) in water to give 1.92 L of solution. The solution has an osmotic pressure of 3.69 torr at 25 °C.

    asked on July 15, 2014
  36. Art

    Choose the pairing that is an example of archival materials a acid free paper such as superglue basalt construction paper salt glass case superglue Acid free paper glass case I say b

    asked on February 1, 2019
  37. Maths

    From a group of 10 people, 5 men and 5 women, six are to be chosen to serve on a committee. a) In how many ways can the committee be chosen? b) Find the probability that two men will be chosen. c) Find the probability that the committee chosen will consist

    asked on March 9, 2016
  38. Chemistry

    How many milliliters of O2 are consumed in the complete combustion of a sample of hexane, C6H14, if the reaction produces 325 mL of CO2? Assume all gas volumes are measured at the same temperature and pressure. The reaction is 2C6H14(g) + 19O2(g) ->

    asked on July 8, 2014

    If it takes 4.12 J of work to stretch a Hooke's law spring 12.1 cm from its unstressed length, determine the extra work required to stretch it an additional 10.0 cm.

    asked on September 29, 2009
  40. chemistry

    When 1.0 mol of ammonia gas in injected into a o.50L flask, the following reaction proceeds to equilibrium. 2NH3 N2 (g) + 3H2 (g) At equilibrium, 0.30 mol of hydrogen gas is present. a) calculate the equilibrium concentrations of N2 and Nh3. b) what is the

    asked on November 26, 2006
  41. physics

    A spy in a speed boat is being chased down a river by government officials in a faster craft. just as the officials' boat pulls up next to the spy's boat both boats reach the edge of a 5.0meter waterfall. If the spies speed is 15m/s and the officials'

    asked on November 6, 2010
  42. chemistry

    convert a pressure of 1.75 atm to kpa

    asked on June 4, 2012
  43. Physics

    5. A grating with 400 lines per mm is illuminated with light of wavelength 600.0 nm. (a) Determine the angle at which the maxima are observed (b) Determine the largest order (n) that can be seen with this grating and this wavelength.

    asked on March 9, 2016
  44. Art

    Choose the pairing that is an example of archival materials a acid-free paper superglue be salt construction paper for the glass case superglue the acid free paper glass case I think it is D

    asked on February 1, 2019
  45. Physics

    A garden hose is used to fill a drum with water. The hose is held 0.88 m above the ground. The cross-sectional area of the 2.0 cm diameter hose is two times the cross-sectional area at the spout end where the water is coming out and the gage pressure

    asked on July 3, 2019
  46. Chemistry

    When 4.76 g of a solid mixture composed of NH4Cl and CaCl2 was dissolved in 100.0 mL of water, the temperature of the water rose by 4.73°C. How many grams of each substance was in the mixture?

    asked on June 26, 2014
  47. more statistics

    The percent of fat calories that a person in America consumes each day is normally distributed with a mean of 36 and a standard deviation of about 10. Suppose that 16 individuals are randomly chosen for an experiment. Completely describe the distribution

    asked on April 26, 2013
  48. college physics

    How many revolutions per minute would a 18 m-diameter Ferris wheel need to make for the passengers to feel "weightless" at the topmost point?

    asked on October 2, 2011
  49. Chemistry

    Benzene reacts with hot concentrated nitric acid dissolved in sulfuric acid to give chiefly nitrobenzene, C6H5NO2. A by-product is often obtained, which consists of 42.86% C, 2.40% H, and 16.67% N (by mass). The boiling point of a solution of 5.5 g of the

    asked on July 14, 2014
  50. Jiishka

    How do you put a webpage to this website?

    asked on November 15, 2011
  51. Chemistry

    24) It was found that a 20.00 mL portion of a solution of oxalic acid, H2C2O4, requires 6.69 mL of 0.200 M K2Cr2O7 for complete reaction in an acidic solution. In the reaction, the oxidation product is CO2 and the reduction product is Cr3+. How many

    asked on July 1, 2014
  52. physics

    It takes the elevator in a skyscraper 4.0 to reach its cruising speed of 10 . A 60 passenger gets aboard on the ground floor.What is the passenger's apparent weight while the elevator is speeding up?

    asked on October 22, 2010
  53. vectors

    Find any vector w that is perpendicular to both u = 3j + 4k and v = 2i. i, j, k are basis vectors. Textbook answer: (0,4,-3) My attempt: used any scale factor variation, like 4j-3k or -8j+6k to get w=8j-6k How do i solve this the longer way?

    asked on May 27, 2018
  54. chem

    How many molecules are in 12.2 g NO2? Answer in units of molec

    asked on April 18, 2012
  55. physics

    What is the minimum work needed to push a 950 kg car 890 m up along a 8.0 degree incline? Assume the effective coefficient of friction retarding the car is 0.22.

    asked on October 10, 2011
  56. math

    The scale model of a rectangular patio will be enlarged by a scale factor of 2.5 to create the actual patio. The actual patio will be 15 feet by 20 feet. Which is the area of the scale model? 48 square feet 60 square feet 120 square feet 300 square feet

    asked on July 20, 2015
  57. Chemistry

    12) Naturally occurring argon is composed of 0.3365% of 36Ar (atomic mass, 35.9675 u), 0.0632% of 38Ar (atomic mass, 37.9627 u), and 99.6003% of 40Ar (atomic mass, 39.9624 u). Use these data to calculate the average atomic mass of argon.

    asked on July 1, 2014
  58. English

    Give a brief summary of Home Place by guy vanderhaeghe.

    asked on September 18, 2018
  59. Chemistry

    Benzene reacts with hot concentrated nitric acid dissolved in sulfuric acid to give chiefly nitrobenzene, C6H5NO2. A by-product is often obtained, which consists of 42.86% C, 2.40% H, and 16.67% N (by mass). The boiling point of a solution of 5.5 g of the

    asked on July 15, 2014
  60. Chemistry

    For the reaction: CH4(g) + 2O2(g)-->CO2(g)+2H2O (l) ÄH = -50.38 kJ/mol, How many moles of methane (CH4) must be burned to produce 137 kJ of heat?

    asked on November 7, 2010

    A potential energy function for a two-dimensional force is of the form U = 2.46x3 y - 5.05x (which has units of J). Calculate the force that acts at the point (1.26 m,1.18 m).

    asked on September 29, 2009
  62. chem

    A sample of hydrogen gas occupies 16.8 L at STP. How many moles of the gas are present? Answer in units of mol

    asked on April 19, 2012
  63. Physics

    Consider the conical pendulum, a mass on the end of a string, with the other end of the string fixed to the ceiling. Given the proper push, this pendulum can swing in a circle at an angle q of 25.5 with respect to the vertical, maintaining the same height

    asked on November 13, 2012

    Estimate the terminal speed of a wooden sphere (density 0.700 g/cm3) falling through air if its radius is 3.20 cm and its drag coefficient is 0.470.

    asked on September 24, 2009
  65. Chemistry

    A student was required to prepare 250.0 mL of a hypochlorous acid/sodium hypochlorite buffer in which the concentration of the weak acid component was 0.073 M and the concentration of the conjugate base was 0.046 M. The student was supplied with 0.365 M

    asked on February 5, 2015
  66. vectors

    Upon reaching a speed of 215 km/h on the runway, a jet raises its nose to an angle of 18º with the horizontal and begins to lift off the ground. a. Calculate the horizontal and vertical components of its velocity at this moment. b. What is the physical

    asked on May 26, 2018
  67. Physics

    A rock is thrown straight up at 22.0 m/s from a roof of a 30.0 m tall building. After rising, the rock falls on the street below. Ignoring air resistance, how much time is the rock in the air? Show the work please :)

    asked on May 24, 2016
  68. chem

    Determine the mass of 7.79 ×1023 atoms Cl. Answer in units of g

    asked on April 18, 2012
  69. Chemistry

    A solution of acetic acid, CH3COOH, has a concentration of 0.218 M and a density of 1.00 g mL-1. What is the molality of this solution?

    asked on July 14, 2014
  70. english

    Need Help Please..!!! During the Victorian period, there were many social changes and intellectual developments. As a result, a crisis of faith rocked society. How does In Memoriam, A. H. H. by Alfred, Lord Tennyson reflect that crisis? a)Grieving, the

    asked on October 31, 2013
  71. Maths

    Two tetrahedral dice are thrown; one is red and the other is blue . The number on which each lands is noted, the faces being marked 1,2,3,4. Find the probability that the sum of the numbers on which the dice lands is 6 given that the red die lands on an

    asked on February 14, 2016
  72. Physics

    A 0.565 kg wood block is firmly attached to a very light horizontal spring (k = 185 N/m) as shown in Fig. 6-40. It is noted that the block-spring system, when compressed 5.0 cm and released, stretches out 2.3 cm beyond the equilibrium position before

    asked on February 16, 2013
  73. geography

    Latitude lines measure distance in degrees north and south of this? is it equator?

    asked on April 15, 2009
  74. chemistry

    Suppose that the microwave radiation has a wavelength of 12 cm . How many photons are required to heat 295 mL of coffee from 25.0 ∘C to 62.0 ∘C? Assume that the coffee has the same density, 0.997 g/mL , and specific heat capacity, 4.184 J/(g⋅K) , as

    asked on June 9, 2019
  75. vectors

    A 35-kg trunk is dragged 10 m up a ramp inclined at an angle of 12º to the horizontal by a force of 90 N applied at an angle of 20º to the ramp. At the top of the ramp, the trunk is dragged horizontally another 15 m by the same force. Find the total work

    asked on May 28, 2018
  76. Chemistry

    If a current of 3.00 A is applied to a cell containing a 400g copper anode, determine the final mass of the copper anode after the cell runs for 48.0h

    asked on July 11, 2016
  77. AP Calc

    A rectangle is inscribed into the region bounded by the graph of f(x)=(x^2-1)^2 and the x-axis, in such a way that one side of the rectangle lies on the x-axis and the two vertices lie on the graph of f(x). What is the maximum possible area of such a

    asked on November 22, 2014
  78. Math

    Why did Karjam Get a flat tire.

    asked on October 9, 2013
  79. Super Easy Math Question

    3x^2-12x+11=0 Solve for x.

    asked on October 19, 2011
  80. chemistry

    Consider the combustion of glucose: C6H12O6(s) + 6O2(g) 6CO2(g) + 6H2O(g) H = −3 kJ/mol Which condition I) Adding more carbon dioxide; II) Performing the reaction in a hotter environment; III) Decreasing the pressure of the system; IV) Adding a reagent

    asked on April 3, 2012
  81. physics

    Consider a frictionless track as shown in Figure P6.48. A block of mass m1 = 4.30 kg is released from A. It makes a head on elastic collision at B with a block of mass m2 = 9.00 kg that is initially at rest. Calculate the maximum height to which m1 rises

    asked on July 16, 2010
  82. Government

    I have to connect littering to a specific amendment in the Bill of Rights. I have read all of them. Could someone help? I’m stuck.

    asked on May 4, 2019
  83. Chemistry

    Methane is formed in landfills by the action of certain bacteria on buried organic matter. If a sample of methane collected from a landfill has a volume of 200. mL at 741 torr and 27.2 °C, how many grams of methane are in the sample? I get the PV=nRT p is

    asked on July 9, 2014

    A luggage carousel at an airport has the form of a section of a large cone, steadily rotating about its vertical axis. Its metallic surface slopes downward toward the outside, making an angle of 23.0 degrees with the horizontal. A piece of luggage having

    asked on September 21, 2009
  85. Chemistry

    Fe2O3 + Fe + H2SO4 → FeSO4 + H2O How would I balance this using oxidation numbers? Is the Fe2 being reduced and the Fe being oxidized?

    asked on December 8, 2015
  86. Physics

    It takes earth 365 days to complete one orbit around the sun. Knowing that the magnitude of the average acceleration of the earth experiences is over half an orbit is 3.78 x 10^-3 m/s^2, what is the average speed with which it travels?

    asked on October 15, 2018
  87. Chemistry

    18) Aspirin is a monoprotic acid called acetylsalicylic acid. Its formula is HC9H7O4. A certain pain reliever was analyzed for aspirin by dissolving 0.534 g of it in water and titrating it with 0.0446 M KOH solution. The titration required 26.73 mL of

    asked on July 1, 2014
  88. Chemistry

    13) Mercury is an environmental pollutant because it can be converted by certain bacteria into the very poisonous substance dimethyl mercury, (CH3)2Hg. This compound ends up in the food chain and accumulates in the tissues of aquatic organisms,

    asked on July 1, 2014
  89. english

    Critical thinking: alien tour guide

    asked on February 23, 2012
  90. math

    what is the unit rate for 22 gallons of gas to go 682 miles

    asked on January 2, 2013
  91. science

    Whats a funny acrostic joke for beryllium

    asked on September 27, 2019
  92. Calculus

    Find two positive numbers that satisfy the given requirements. The product is 147 and the sum of the first number plus 3 times the second number is a minimum.

    asked on October 25, 2011
  93. 11th grade visual art

    first of all this is my first time so i don't know if i am doing it right. I need help i have holiday homework that i need to do but i cant find good enough info for question 1 and i don't understand how to do question 2 below i will write homework

    asked on December 5, 2008
  94. Java

    If I declare a method static, does it mean only a class can call that method?

    asked on May 5, 2019
  95. spanish

    Write the correct conjugation of tener for the following sentences: 9. ¿Por qué _________ (Jose) sueño por la mañana? 10. Mi amiga _________ tres hijos. 11. ¿Cómo se dice "Patricio tiene ganas de comer" en inglés? 12. ¿Cómo se dice "Ana has to

    asked on May 14, 2009
  96. language arts

    a person who studies and collects rocks for fun

    asked on March 17, 2008
  97. math

    67 is the difference of Holly's age and 23.

    asked on January 24, 2020
  98. science

    A solution of aqueous ammonia contains 28.0% NH3 by mass. the solution has a density of 0.898g/mL. calculate the volume of this solution required to make 425mLof 0.320M NH3 solution.

    asked on November 18, 2016
  99. math

    If y varies directly as the square root of x and y = 47 when x = 49, find y if x = 2401. (Round off your answer to the nearest hundredth.)

    asked on March 10, 2016
  100. Chemistry

    At 21.0 °C, a solution of 23.71 g of a nonvolatile, nonpolar compound in 30.64 g of ethylbromide, C2H5Br, had a vapor pressure of 319.7 torr. The vapor pressure of pure ethyl bromide at this temperature is 400.0 torr. Assuming an ideal solution, what is

    asked on July 14, 2014


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