Popular questions and responses by dave
  1. math

    Fido weighs 26 pounds more than Fifi. Fifi weighs 12 pounds less than Rover. If the sum of their weights is 71, how much does Fifi weigh?

    asked on February 4, 2017
  2. statistics

    A random sample of size 36 is taken from a population with mean 50 and standard deviation 5. Find P( < 51.5).

    asked on July 6, 2012
  3. spanish

    Answer the questions negatively, using the imperfect tense. Make sure to include the direct object pronoun when needed. Follow the model. Modelo ¿Juega Daniel al fútbol? No, pero antes lo jugaba. ¿Hablas por teléfono? No hablaba ¿Fue a la playa

    asked on March 31, 2011
  4. Chemistry

    Suppose you titrated a sample of sulfuric acid (diprotic acid) with a 0.250 M solution of NaOH. Given the data in the table below, what is the concentration of the sulfuric acid solution?

    asked on December 6, 2016
  5. Social Studies

    1. Which of the following apply to fascism? Select all that apply. A rooted in militarism B extreme nationalism C respect for minorities D blind loyalty to the state I think its A,B, and c ----------------------------------- 2. Which of the following best

    asked on February 26, 2017
  6. Math

    Find the 999th derivative of cos x. I got sin x.

    asked on October 20, 2016
  7. General Chemistry

    A student dissolved 4.00 g of Co(NO3)2 in enough water to make 100. mL of stock solution. He took 4.00 mL of the stock solution and then diluted it with water to give 275. mL of a final solution. How many grams of NO3- ion are there in the final solution?

    asked on October 12, 2010
  8. Chemistry

    Calculate the equilibrium constant for the following reaction at room temperature, 25 ∘C: N2(g)+O2(g)→2NO(g)

    asked on June 21, 2013
  9. physics

    A uniform pole 7m long and weighing 10kg is supported by a boy 2m from one end and a man 3m from the other end.At what point must a 20kg weight be attached so that the man would support thrice as much weight as the boy?

    asked on June 21, 2018
  10. Math

    a geometric progression has a third term of 20 and a sum to infinity which is three times the first term. find the first term

    asked on May 12, 2016
  11. Calculus

    Gloria would like to construct a box with volume of exactly 45ft^3 using only metal and wood. The metal costs $15/ft^2 and the wood costs $6/ft^2. If the wood is to go on the sides, the metal is to go on the top and bottom, and if the length of the base is

    asked on November 4, 2015
  12. American History

    Which statement best describes the Monroe Doctrine? A. The United States welcomed European involvement in all issues in North America. B. The United States welcomed any European involvement in South America. C. The United States pledged to involve itself

    asked on April 3, 2015
  13. Physics

    The initial kinetic energy imparted to a 0.1 kg bullet is 1036 J. The acceleration of gravity is 9.81 m/s2 . Neglecting air resistance, find the range of this projectile when it is fired at an angle such that the range equals the maximum height attained.

    asked on February 27, 2011
  14. Science

    Which of these statements regarding enzymes is FALSE?

    asked on February 26, 2007
  15. Physics

    A glass bottle full of mercury has a mass 500g. 35°C, 243g of mercury are expelled. Calculate the mass of f mercury remaining in the | bottle. (Cubic expansivity. of mercury . is 1.8×x10^-4 K^(-1), linear . expansivity .of glass is 8.0×10^(-4)k^(-1)

    asked on December 28, 2019
  16. Physics

    A dike in Holland springs a leak through a hole of area 0.80 cm2 at a depth of 1.2 m below the water surface. How much force must a boy apply to the hole with his thumb to stop the leak?

    asked on October 6, 2016
  17. Chemistry-Solubility Product

    Why does effervescence when the Group 2 anion precipitate is acidified imply the presence of (CO3)2- ?

    asked on April 12, 2009
  18. Math/Statistics

    The mean starting salary for graduates in the spring of 2004 was $36,280. Assume that the distribution of starting salaries follows the normal distribution with a standard deviation of $3,300. What percent of the graduates have starting salaries between

    asked on November 29, 2010
  19. Economics

    If Mary takes money from her savings account and buys a T-bond from Jody with that money, it's: A. An expansionary fiscal policy. B. An example of contractionary monetary policy. C. An example of expansionary monetary policy D. An example of neutral

    asked on June 24, 2007
  20. Trignometry

    Use the appropriate reciprocal identity to find the approximate value of sin θ for the given value of csc θ. Use a calculator. csc θ = 2.15750581

    asked on September 8, 2017
  21. physics

    Identify the force that propels a rocket. 1)The rocket is propelled by the reaction force of the exhaust gasses bouncing off the air molecules outside the rocket. 2)The rocket is propelled because the action force of the rocket on the exhaust gases is

    asked on October 18, 2016
  22. Biochem

    If .1ml of serum, 5ml of reagent and 4.9ml of distilled water are mixed together what is the dilution of the serum in the final solution

    asked on March 23, 2014
  23. trig

    how do i set this problem up? Find tan (s + t) given that sin s = 1/4, with s in quadrant 2, and sin t = -1/2, with t in quadrant 4.

    asked on May 2, 2010
  24. physics help!!!

    In February 1955, a paratrooper fell 365 m from an airplane without being able to open his chute but happened to land in snow, suffering only minor injuries. Assume that his speed at impact was 60 m/s (terminal speed), that his mass (including gear) was 90

    asked on March 26, 2010
  25. Finance

    At what rate must $500 be compounded for it to grow to 1079.46 in 10 years? 8 percent? i think

    asked on November 12, 2009
  26. physics

    A rugby player runs with the ball directly toward his opponent's goal, along the positive direction of an x axis. He can legally pass the ball to a teammate as long as the ball's velocity relative to the field does not have a positive x component. Suppose

    asked on September 28, 2009
  27. physics/chem

    (a) What equal positive charges (in Coulombs) would have to be placed on two celestial objects with masses 9.40 x 1027 and 1.99 x 1022 kg to neutralize their gravitational attraction? (b) What mass of hydrogen would be needed to provide the positive charge

    asked on March 31, 2008
  28. Economics

    Will the aggregate quantity of goods and services demanded become more sensitive or less sensitive to changes in the price level if an economy becomes closed (that is, as foreign trade disappears)? In terms of the AD/AS diagram, will the AD curve become

    asked on June 18, 2007
  29. chemistry

    For the reaction 2Na(s)+Cl2(g)→2NaCl(s)2Na(s)+Cl2(g)→2NaCl(s), how many grams of NaCl could be produced from 20 L of Cl2Cl2 (at STP)?

    asked on March 3, 2017
  30. Calculus

    Use Simpson's rule with n = 4 to approximate. Keep at least 2 decimal places accuracy. Integrate: (cos(x))/(x) x=1 to 5

    asked on May 3, 2016
  31. Physical Science

    The main difference between the internal combustion engine and the diesel engine is that the diesel engine A. does not have a crankshaft. B. does not utilize pistons. C. has no connecting rods. D. has no ignition system. pretty sure its d

    asked on February 27, 2015
  32. Math - Business Stats. PLS HELP!

    help pls!!! thank u in advance, i appreciate it greatly Alex, Alicia, and Juan fill orders in a fast-food restaurant. Alex incorrectly fills 20% of the orders he takes. Alicia incorrectly fills 12% of the orders she takes. Juan incorrectly fills 5% of the

    asked on October 10, 2014
  33. chem

    A 6.75-g sample of gold (specific heat capacity = 0.130 J/g °C) is heated using 55.8 J of energy. If the original temperature of the gold is 25.0°C, what is its final temperature?

    asked on March 14, 2013
  34. physics

    A ball is released from a hot air balloon moving downward with a velocity of -10.0 meters/second and a height of 1,000 meters. How long did it take the ball to reach the surface of Earth? Given: g = -9.8 meters/second2.

    asked on July 10, 2012
  35. physics

    hi, reading over momentum notes and i just want to clarify a few things. if i had a system containing a cart that was moving (cart 1) and then a cart that was stationary (cart2)would there be any net external force acting on the system between the initial

    asked on November 13, 2011
  36. chemistry

    The heat of vaporization of a substance is 2900 J/g at its boiling point of 313C. How much of this substance can be vaporized if 58700 J of energy are available?

    asked on January 17, 2011
  37. Trigonometry

    You observe a plane approaching overhead and assume that its speed is 700 miles per hour. The angle of elevation of the plane is 16° at one time and 58° one minute later. Approximate the altitude of the plane

    asked on November 22, 2010
  38. Physics Help Please!

    If the price of electrical enegy is $0.10 per kilowatt *hour, find the cost of using electrical energy to heat the water in a 12.0m * 9.00m * 1.5m swimming pool from 15 degrees C to 27 degrees C. So the change in temperature is 285.15 , the volume is

    asked on April 6, 2010
  39. Computers

    Show what the final output of this function will be. The answer will be in the form x * Z - y Private Function F(x as Int, y As Int, z as Int) If (y = 1) then Return 2 Else Return x * Z - y + F(x-1,y-1, z) End If End Function

    asked on August 27, 2009
  40. physics/chem

    Calculate the number of coulombs of positive charge in 261 cm3 of (neutral) water. (Hint: A hydrogen atom contains one proton; an oxygen atom contains eight protons.)

    asked on March 31, 2008
  41. calculus : related rates

    a balloon rises at a rate of 3 meters per second from a point on the ground 30 meters from an observer. find the rate of change of the angle of elevation of the balloon from the observer when the balloon is 30 meters above the ground... so i drew a small

    asked on November 5, 2007
  42. Economics

    Which of the following statements would come from someone classified as unemployed? A. I'm not working. I had three interviews this week, and I'm trying to find a job. B. I haven't had a job in a year, and I stopped looking for a job nine months ago. C.

    asked on June 13, 2007
  43. Chemistry

    ELement A has a valence electronic structure of ns2np1. Element B has the valence electronic structure of ns2np5. Write a formula for the compound that would be formed from elements A and B. Element A has three electrons to lose to make the last shell

    asked on April 19, 2007
  44. Science

    During the process of photosynthesis, solar energy is converted into: a. chemical energy. b. heat energy. c. thermal energy. d. mechanical energy. e. nuclear energy. a

    asked on February 26, 2007
  45. Math

    "Cab companies often charge a flat fee for picking someone up and then charge an additional fee per mile driven. Pick a U.S. city and research the rates of two different cab companies in that city. Find companies that charge different amounts per mile and

    asked on November 13, 2017
  46. Algebra

    Given that $x^n - \frac1{x^n}$ is expressible as a polynomial in $x - \frac1x$ with real coefficients only if $n$ is an odd positive integer, find $P(z)$ so that $P\left(x-\frac1x\right) = x^5 - \frac1{x^5}.$

    asked on June 5, 2017
  47. Chemistry

    Nitrogen monoxide reacts with chlorine gas according to the reaction: 2NO (g) + Cl2 (g) ⇔ 2NOCl (g) Kp = 0.27 at 700 K A reaction mixture initially contains equal partial pressures of NO and Cl2 . At equilibrium, the partial pressure of NOCl is 115

    asked on April 4, 2017
  48. physics

    Identify the force that propels a rocket. 1)The rocket is propelled by the reaction force of the exhaust gasses bouncing off the air molecules outside the rocket. 2)The rocket is propelled because the action force of the rocket on the exhaust gases is

    asked on October 18, 2016
  49. Chemistry

    What set of hybrid orbitals is used by Xe in XeO3F2? dsp2 d2sp3 sp3 dsp3 d2sp

    asked on March 2, 2016
  50. Math

    Lim sin(60-x)/2cosx-1 x approaches 60

    asked on January 2, 2016
  51. math

    Consider the equation f(x)= -2 sqrt(X+3). List in order the transformations applied to the parent function.

    asked on October 9, 2015
  52. World History

    Regarding Indonesia, which of the following statements is false? A. Indonesia was formerly the British East Indies. B. The first head of Indonesia was Sukarno. C. The first leader of Indonesia was Suharto. D. Indonesia was formerly the Netherlands East

    asked on March 10, 2015
  53. Electricity and Electronics

    A complete circuit contains two parallel-connected devices and a generator for providing the electromotive force. The resistance of the first device is 12 ohms, the resistance of the second device is 4 ohms, and the voltage developed by the generator is 40

    asked on February 24, 2015
  54. Physics

    The force required to stretch a spring varies directly with the amount the spring is stretched. A force of 29 pounds is needed to stretch a spring 39 inches. How much force is required to stretch the spring 27 inches? Answer in units of lb

    asked on December 6, 2014
  55. O-Chem

    Draw the mechanism of the reaction of (E)-stilbene with Br2.

    asked on November 13, 2014
  56. Precal

    The point (r,theta) in polar coordinates is (7,5) in rectangular coordinates. What is the point (2r, theta + pi/2) in rectangular coordinates? So I tried this problem and got r = sqrt(74). But while finding the value of theta, I got it equal to cot(5/7)

    asked on August 9, 2014
  57. Chemistry

    2CH3CH2CH2OH(l)+9O2(g)→6CO2(g)+8H2O(g) I have to find the delta G delta G of CH3CH2CH2OH(l)=−360.5 KJ/Mol delta G of O2(g)=0 KJ/Mol delta G of CO2(g)=−394.4 KJ/Mol delta G of H20(g)=−228.6 KJ/Mol I keep getting -3426.2 KJ/Mol but its not correct.

    asked on June 21, 2013

    $24,000 is invested for 3 years with an APR of 2% and daily compounding. Balance in the account after 3. years is $ ___

    asked on January 27, 2013
  59. Math

    A piece of aluminum with an unknown mass ios at 85c and is placed in a 2.00 liters of water at 25.0c. The final temperature becomes 33c. What is the mass of aluminum?

    asked on November 8, 2012
  60. Prob and Stats

    The Roper Organization conducted identical surveys 5 years apart. One question asked of women was Are most men basically kind, gentle, and thoughtful? The earlier survey revealed that, of the 3,000 women surveyed, 2,010 said that they were. The later

    asked on September 5, 2011
  61. College math

    What is the probability without replacement of drawing at least one ten (52 card deck)?

    asked on May 2, 2011
  62. Math

    What is the sum of the measures of the interior angles of an 11-side polygon?

    asked on January 12, 2011
  63. math

    a baseball team buys 15 bats for $405. aluminum bats cost $25 and wooden bats cost $30. how many of each type did they buy? Please show work

    asked on November 6, 2010
  64. Chemistry

    A 2.50 gram sample of bronze was dissolved in sulfuric acid. The copper in the sample reacted with sulfuric acid to form copper sulfate. Cu (s) +2 H2SO4 (aq) -> CuSO4 (aq) +2 H2O (l) The copper sulfate formed in this reaction was mixed with I to form

    asked on October 31, 2010
  65. algebra

    While shopping, Jill spent six times as much as Nan. If they spent a total of $112, how much did each person spend?

    asked on October 24, 2010
  66. Psychology

    • Find a peer reviewed article which discusses the effects of optimism on physical and psychological health. • Write a 1400 to 1600-word paper summarizing the article and stating your opinion on the validity of the study or studies.

    asked on August 19, 2010
  67. SCIENCE 1

    The van der waals equation incorporates corrections to the ideal gas in order to account for the properties of real gases one of the correcctions accounts for A.attractions between molecules B.the quantum behavior of molecules C.that average kinetic energy

    asked on May 11, 2010
  68. economics

    if production displays economies of scale, the long run average cost curve is: a) upward sloping b) above the short run average total cost curve C0 below the long run marginal cost curve d) downward sloping

    asked on October 5, 2009
  69. math

    The acceleration of a particle at a time t moving along the x-axis is give by: a(t) = 4e^(2t). At the instant when t=0, the particle is at the point x=2, moving with velocity v(t)=-2. Find the position of the particle at t=1/2 if you could show me how to

    asked on February 23, 2009
  70. physics/chem

    n Fig. 21-41, three identical conducting spheres initially have the following charges: sphere A, 7Q; sphere B, -8Q; and sphere C, 0. Spheres A and B are fixed in place, with a center-to-center separation that is much larger than the spheres. Two

    asked on March 31, 2008
  71. math

    how do you find the reference angle of csc,sec, cot? for example: csc theta= 2 times square root of 3 / 2

    asked on February 4, 2008
  72. Purchasing Power of Income/ Economy

    We use the _________ to determine the purchasing power of income. A. Interest rate. B. Real GDP. C. CPI. D. GDP. E. None of the above. Check this site for your answer. http://www.bls.gov/cpi/

    asked on June 14, 2007
  73. History

    Could someone please find me a website that has great information on Business enterprise in America so I can make a timeline on it. Specific dates that I need are 1906, 1913, 1914 , 1930, 1939. I would greatly appreciate it. This site seems to have the

    asked on April 29, 2007
  74. Algebra II

    Our current assignment is to find the LCM, Least Common Multiple of two polynomials. I think I'm doing it right but I'm not quite sure. For the first question: 2t^2+t-3, 2t^2+5t+3 I have 2t^2+t+3 as the LCM. Is this correct or can somebody step me through

    asked on February 15, 2007
  75. AP Chemistry

    (a) What is the pH of a 2.0 molar solution of acetic acid. Ka of acetic acid = 1.8 x 10¯5 (b) A buffer solution is prepared by adding 0.10 liter of 2.0 molar acetic acid solution to 0.1 liter of a 1.0 molar sodium hydroxide solution. Compute the hydrogen

    asked on February 13, 2007
  76. Math

    1. Let T = {a, b, c, d}. a. Find an example of a relation of this set that is transitive, but neither reflexive nor symmetric. b. Find an example of a relation on this set that is both transitive and symmetric, but not reflexive.

    asked on April 24, 2020
  77. Chemistry

    What intermolecular forces exist in dichloromethane, n-pentanol, and toluene besides London Dispersion Forces?

    asked on April 9, 2020
  78. Maths

    The height h, in metres, of a ball thrown from a cliff can be modelled by the function with the rule h(t) = 20+15t-5t^2, where t less than/equal to 0 is the time measured in seconds. a) find the initial height of the ball b) find the time at which the ball

    asked on March 11, 2020
  79. math

    : Find the value of x in the figure. ​

    asked on June 11, 2019
  80. Math

    A is partly constant and partly varies as b when A is equal to 15 B was 2 when is equal to A 45 is B equal to 8

    asked on March 9, 2019
  81. Calculus AB/BC

    What's the purpose of finding derivatives? I don't understand why you would need to find a derivative, which is the tangent of the slope of a point on a graph, to find something like "How far did Bob fall". Confusing. Please help. Thank you!

    asked on November 2, 2017
  82. Math

    Solve the indefinite integral of 1/sqrt(x^2+2x+5). I solved it all out by completing the square and then trig sub and then drawing a triangle to go back to x variable and got: ln |(sqrt(x^2+2x+5)/2 + (X+1)/2 ) | but the book answer is: ln |(sqrt(x^2+2x+5)

    asked on October 10, 2017
  83. Math

    Solve the indefinite integral of 1/sqrt(x^2+2x+5). I solved it all out by completing the square and then trig sub and then drawing a triangle to go back to x variable and got: ln |(sqrt(x^2+2x+5)/2 + (X+1)/2 ) | but the book answer is: ln |(sqrt(x^2+2x+5)

    asked on October 10, 2017
  84. Math

    Evaluate the integral from [sqrt(pi/2), sqrt(pi)] of x^3*cos(x^2) by first making a substitution and then using integration by parts. I let u = x^2 and du= 2x dx but then it doesn't equal that in the equation?

    asked on September 29, 2017
  85. Chemistry

    A 10.0000 g block of aluminum is heated and placed in a stream of oxygen gas, resulting in the formation of aluminum oxide on the surface of the block. The block is cooled and weighed and found to have a mass of 11.6471 g. The block is then placed in a

    asked on September 26, 2017
  86. Math

    Evaluate the integral of (x^3 + x^4*tanx) from [-pi/4, pi/4] How do we know which one to let equal to u in order to start this whole process? The answer in the book is 0.

    asked on September 13, 2017
  87. Ed Tech

    To edit the text in a smartart graphic, what must be done first ?

    asked on August 29, 2017
  88. math

    a rectangular plate 120 ft long and 80 ft wide is submerged vertically with the longer edge in the surface of the water find the force on one side of the plate

    asked on May 16, 2017
  89. mechanics

    a rectangular plate 120 ft long and 80 ft wide is submerged vertically with the longer edge in the surface of the water find the force on one side of the plate

    asked on May 16, 2017
  90. Calculus

    The region enclosed by the graph e^(x/2), y=1, and x=ln(3) is revolved around the x-axis. Find the volume of the solid generated. I don't understand if we have to use the washer method or the disk method for this one because when I drew it out on a graph

    asked on March 1, 2017
  91. Social studies

    Which of the following factors was most responsible for an unequal distribution of wealth? A There was an increase in business profits. B Wages were not keeping pace with profits of business owners. C Wages were not keeping pace with profits of business

    asked on February 23, 2017
  92. Physics

    Which of the following is an element? H2O Hydrogen Carbon dioxide A supernova

    asked on October 7, 2016
  93. physics

    The contestants at a cycling race travel around a 0.5km radius track. The peloton travels 33 laps in 1 hour to complete the race. What is the total angular distance they have traveled? On the first lap, they start from rest and after traveling ½ the

    asked on June 30, 2016
  94. Math

    A pharmaceutical salesperson receives a monthly salary of $2500 plus a commission of 7 percent of sales. Write a linear equation for the salesperson monthly wage in terms of monthly sales.

    asked on June 7, 2016
  95. chem

    Determine the mass of oxygen in a 7.2-g sample of Al2(SO4)3

    asked on April 18, 2016
  96. Math

    Can somebody show or explain this to me: Change 6 2/3% to fraction and .6 1/3 to a decimal or fraction.

    asked on February 13, 2016
  97. Physics

    A watertight car is submerged under water. What force is required to open a door of area 1.12 m2 if the average depth of water at the door is 1.50 m?

    asked on December 8, 2015
  98. math

    5 inches is what fraction of a foot? A. 1/3 B. 1/2 C. 5/12 D.5/24 my answer is C. is it correct?

    asked on October 27, 2015
  99. Math

    Find the area of a triangle with base of 15 m and altitude of 12 m

    asked on August 6, 2015
  100. Physics (optics)

    A ray of light traveling in air strikes the midpoint of one face of an equiangular glass prism (n = 1.74) at an angle of exactly 30.0â—¦ Trace the path of the light ray through the glass and find the angle of incidence of the ray at the bottom of the

    asked on May 12, 2015


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