Popular questions and responses by john
  1. Calculus

    A stone is dropped from the upper observation deck of a tower, 200 m above the ground. (Assume g = 9.8 m/s^2.) a)Find the distance (in meters) of the stone above ground level at time t. b)With what velocity does it strike the ground? (Round your answer to

    asked on November 13, 2011
  2. Statistics

    you roll two fair dice, a green one and a red one? (a) are the outcomes on the dice independent? (b)Find P(1 on green die and 2 on red die) (c)Find P(2 on green die and 1 on red die) (d)Find P(1 on green die and 2 on red die) or (2 on green die and 1 on

    asked on October 30, 2016
  3. English

    1. Early in Act II of The Phantom Tollbooth, Milo meets a character named Kakafonous A. Dischord, Doctor of Dissonance. Stage directions tell you that "Two screeches and a bump are heard." The doctor's name and the stage directions are clues to the

    asked on December 3, 2018
  4. calculus

    If an arrow is shot upward on Mars with a speed of 52 m/s, its height in meters t seconds later is given by y = 52t − 1.86t2. (Round your answers to two decimal places.) What is the average speed over the given time intervals? (i) [1, 2] (ii) [1, 1.5]

    asked on January 31, 2018
  5. math

    In a family with 4 children what is the probability of having 1 boy and then 3 girls, in that order? (Exclude multiple births and assume all outcomes are equally likely). In a family with 4 children, what is the probability of having 1 boy and 3 girls, in

    asked on November 8, 2015
  6. math

    Pizzaz pg.103 Did you hear about...

    asked on January 8, 2012
  7. Physics

    Question: A Toyota car travelled at the rate of 70 km/hour leaves the house 2 hours after a Kia car has left and overtakes it in 5 hours. at what rate was Kia car travelling? What's the Formula pls? Thanks

    asked on July 21, 2016
  8. physics vectors

    Consider the two vectors A with arrow = 3 i − j and B with arrow = − i − 6 j. Calculate the directions of A with arrow + B with arrow and A with arrow − B with arrow. A with arrow + B with arrow ° (counterclockwise from the +x axis) A with arrow

    asked on August 23, 2016
  9. Physics

    A box is given a push so that it slides across the floor. How far will it go, given that the coefficient of kinetic friction is 0.24 and the push imparts an initial speed of 3.8 m/s?

    asked on October 14, 2010
  10. chemistry

    1. Calculate the standard enthalpy change for the reaction: C2H4(g) + H2(g) → C2H6(g) given that the enthalpy of combustion for the reactants and products are: ΔHºc(C2H4)(g) = -1411 kJ mol^-1 ΔHºc(C2H6)(g) = -1560 kJ mol^-1 ΔHºc(H2)(g) = -286 kJ

    asked on July 19, 2014
  11. algebra

    Cryptic Quiz 1. What do you call a skydiver with the flu? 2. How do you crash a houseboat party?

    asked on May 2, 2013

    A Sample of gas originally at 25 degrees C and 1 atm pressure in a 2.5 L container is allowed to expand until the pressure is .85 atm and the temperature is 15 degrees C. What is the final volume of gas? Did anyone get 2.6 L

    asked on May 12, 2012
  13. math

    A hacker is trying to guess someone's password. The hacker knows (somehow) that the password is 14 characters long, and that each character is either a lowercase letter, (a, b, c, etc), an uppercase letter (A, B, C, etc) or a numerical digit (0, 1, 2, 3,

    asked on November 8, 2015
  14. Pre-Calc Helppp!!!

    Use the Law of Sines to solve for all possible triangles that satisfy the given conditions. (If an answer does not exist, enter DNE. Round your answers to one decimal place. Below, enter your answers so that B1 is smaller than B2.) a = 39, c = 40, angle A

    asked on March 31, 2012

    A mixture of Xe, Kr, and Ar has a total pressure of 6.7 atm. What is the mole fraction of Kr if the partial pressures of XE and Ar are 1.6 atm and 2.8 atm? Did anyone get .343 ?

    asked on May 12, 2012
  16. Physics

    You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.5 m above the ground, and it is moving at a speed of 8.0 m/s. (a) How much time does it take for the tennis ball to reach its maximum height? (b) What is the

    asked on September 6, 2014
  17. science

    A chair of mass 15.5 is sitting on the horizontal floor; the floor is not frictionless. You push on the chair with a force = 38.0 that is directed at an angle of 42.0 below the horizontal and the chair slides along the floor.Use Newton's laws to calculate

    asked on August 3, 2012
  18. Calculus

    A spinner is used for which it is equally probable that the pointer will land on any one of six regions. Three of the regions are colored red , two are colored green, and one in colored yellow. If the pointer is spun twice, find the probability it will

    asked on December 10, 2007
  19. english

    21. identify the appropriate punctuation for the underlined word or phrase In High School, I enjoyed reading (The Catcher in the Rye)

    asked on October 25, 2016
  20. college physics

    Superman must stop a 190-km/h train in 180m to keep it from hitting a stalled car on the tracks. part a)If the train's mass is 3.8×10^5kg , how much force must he exert (find the magnitude)? part b)Compare to the weight of the train (give as %). partc)

    asked on April 29, 2012
  21. physics

    If a car rolls gently(vo=0) off a vertical cliff, how long does it take to reach 85km/h?

    asked on September 13, 2010
  22. College Math

    A block with a mass of m = 31 kg rests on a frictionless surface and is subject to two forces acting on it. The first force is directed in the negative x-direction with a magnitude of F1 = 11 N. The second has a magnitude of F2 = 22.75 N and acts on the

    asked on October 9, 2014
  23. science

    Both carbon dioxide and water are pure substances. How are they similar to each other? A. both substances have a set ratio of atoms that cannot be separated by physical means B. both substances have a set ratio of atoms that can be separated by physical

    asked on October 8, 2015
  24. Physics

    In uniform circular motion, which of the following quantities are constant: speed, instantaneous velocity, tangential velocity, radial acceleration, tangential acceleration? Which of these quantities are zero throughout the motion?

    asked on October 8, 2013
  25. Chemistry

    In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is ________ if the partial pressures of He and Ne are 1.50 and 2.00 atm respectively. pHe = 1.50 atm. pNe = 2.00 atm. pAr = 8.40 atm - 1.50 - 2.00 = ?? mole

    asked on January 14, 2007
  26. Science

    What is the goal of technology understand the natural world improve how devices operate improve how people live understand how systems operate My answer A

    asked on September 14, 2017
  27. math

    Jane is organizing a fundraiser to buy a ping-pong table for the community center. The table costs $500.00. Jane is asking contributors to pay for an equal share of the cost of the table. She already has five contributors lined up. What function models the

    asked on February 7, 2019
  28. Chemistry

    I've tried to solve this question multiple ways I just can't seem to get it. I just don't understand what I should be doing. An organic liquid is a mixture of methyl alcohol () and ethyl alcohol (). A 0.220- sample of the liquid is burned in an excess of

    asked on September 16, 2012
  29. Chemistry

    Ni2+(aq)+Mg(s)→Ni(s)+Mg2+(aq) Indicate the half-reaction occurring at Anode. Indicate the half-reaction occurring at Cathode.

    asked on May 14, 2014
  30. math

    Cyndee wants to invest $50,000. Her financial planner advises her to invest in three types of accounts: one paying 3%, one paying 5 1/2%, and one paying 6% simple interest per year. Cyndee wants to put twice as much in the lowest-yielding, least-risky

    asked on April 27, 2016
  31. algebra

    Homer is giving some cookies to each of his three brothers. To the oldest, he gives half of the cookies and half a cookie. He then gives half of what is now left and half a cookie to his second brother. Finally, he gives half of what is now left and half a

    asked on November 24, 2009
  32. Physics

    Bethany, who weighs 420N, lies in a hammock suspended by two ropes tied to two trees. The left rope makes an angle of 45 degrees with the ground, the right one makes an angle of 30 degrees. Find the tension of the left rope. Find the tension of the right

    asked on August 25, 2019
  33. Physics

    A police car traveling at 94.5 km/h is traveling west, chasing a motorist traveling at 77.2 km/h. (a) What is the velocity of the motorist relative to the police car? The magnitude and its direction (b) What is the velocity of the police car relative to

    asked on August 1, 2012
  34. physics

    A nurse pushes a cart by exerting a force on the handle at a downward angle 35.0º below the horizontal. The loaded cart has a mass of 28.0 kg, and the force of friction is 60.0 N. (a) Draw a free-body diagram for the system of interest. (b) What force

    asked on September 18, 2012
  35. math

    Every cereal box has a gift inside, but you cannot tell from the outside what the gift is. The store manager assures you that 16 of the 58 boxes on the shelf have the secret decoder ring. The other 42 boxes on the shelf have a different gift inside. If you

    asked on November 8, 2015
  36. chemistry

    what is the mass in grams? a) 3.011 x 10^23 atoms F b)1.50 x 10^23 atoms Mg c)4.50 x 10^12 atoms Cl d)8.42 x 10^18 atoms Br e) 25 atoms w f) 1 atom Au can you please explain a and b to me then i'll come back later and see if i did the rest right? Thanks in

    asked on February 23, 2008
  37. Chemistry

    Tarnish on iron is the compound FeO. A tarnished iron plate is placed in an aluminum pan of boiling water. When enough salt is added so that the solution conducts electricity, the tarnish disappears. Imagine that the two halves of this redox reaction were

    asked on May 14, 2014
  38. Data Management

    How many different sums of money can be formed from one $2 bill, three $5 bills, two $10 bills, and one $20 bill? the answer at the back of the book is 23, but i don't know how to solve it.

    asked on March 6, 2010
  39. chemistry

    In a large building, oil is used in a steam boiler heating system. The combustion of 1.0 lb of oil provides 2.2×107J. Part A How many kilograms of oil are needed to heat 110 kg of water from 24 ∘C to 100∘C? (Assume that 1lb=454g, the specific heat of

    asked on September 23, 2016
  40. atlantic high

    Why Was Professor CLabberhead Utterbunk Holding Up a Piece of Bread ?

    asked on April 18, 2009
  41. math

    A confectioner has 300 pounds of a chocolate that is 1 part cocoa butter to 7 parts caramel. How much chocolate that is 1 part cocoa butter to 15 parts caramel should be combined with the first in order to create a new chocolate that is 1 part cocoa butter

    asked on March 5, 2016
  42. Calculus

    Which of the following integrals correctly computes the volume formed when the region bounded by the curves x^2 + y^2 = 100, x = 6, and y = 0 is rotated around the y-axis? I've narrowed it down to either pi∫(sqrt(100-y^2)-6)^2 dy or

    asked on January 22, 2016
  43. Econ

    Suppose the government wants to reduce the total pollution emitted by three firms in its area. Currently, each firm is creating 4 units of pollution in the area, for a total of 12 pollution units. The government wants to reduce total pollution in the area

    asked on May 19, 2012
  44. english

    25. which sentence is punctuated correctly? a. "Are you finished yet, Miriam asked?" b. Are you finished yet, " Miriam asked?" c. "Are you finished yet"?Miriam asked. d. "Are you finished yet?" Miriam asked.*** 26. Which sentence correctly uses punctuation

    asked on October 27, 2016
  45. English

    Parenthetical expressions include information that may be helpful but are not essential to the meaning of a sentence. They are de-emphasized by ________. A. dashes B. parentheses C. commas D. brackets I'm not really understanding this question. It has to

    asked on February 13, 2015
  46. physics

    if two forces 10N and 20N are inclined at angle 60degree to each other. Find the resultant force.

    asked on September 27, 2015
  47. calculus

    At noon, ship A is 110 km west of ship B. Ship A is sailing east at 25 km/h and ship B is sailing north at 15 km/h. How fast is the distance between the ships changing at 4:00 PM?

    asked on October 13, 2011
  48. physics

    A pelican flying along a horizontal path drops a fish from a height of 5.4m. The fish travels 8.0 m horizontally before it hits the water below. What was the pelican's speed?

    asked on October 25, 2010
  49. Science

    A group of parts that work together is called. A. Technology B. Process. C. System. D. Feedback I think its C?

    asked on September 20, 2016
  50. Wave

    What feature is NOT defined for a wave pulse? a)period b)wave speed c)the position of a particle at a certain time d)a defined source

    asked on February 8, 2014
  51. Finance

    Antiques ‘R’ Us is a mature manufacturing firm. The company just paid a dividend of $11.45, but management expects to reduce the payout by 4.5 percent per year, indefinitely. Required: If you require a return of 11 percent return on this stock, what

    asked on March 11, 2015
  52. Physics

    In Figure 9-61, block 1 (mass 2.0 kg) is moving rightward at 8 m/s and block 2 (mass 4.8 kg) is moving rightward at 2.8 m/s. The surface is frictionless, and a spring with spring constant of 1180 N/m is fixed to block 2. When the blocks collide, the

    asked on December 10, 2012
  53. physics

    in the hydraulic machine shown, you observe that when the small piston is pulled down 10cm, yhe large piston is raised 1 cm. if the small piston is pushed down with a force of 100n, what is the most weight that the large piston can support?

    asked on January 26, 2012
  54. chemistry

    Calculate the standard cell potential for each of the electrochemical cells? 2Ag+(aq)+Pb(s)→2Ag(s)+Pb2+(aq) E∘cell......V? 2ClO2(g)+2I−(aq)→2ClO−2(aq)+I2(s) E∘cell......V? O2(g)+4H+(aq)+2Zn(s)→2H2O(l)+2Zn2+(aq) E∘cell......V?

    asked on April 11, 2014
  55. Physics

    An ice cube is placed in a microwave oven. Suppose the oven delivers 105 W of power to the ice cube and that it takes 32,200 J to melt it. How long does it take for the ice cube to melt?

    asked on March 16, 2010
  56. Pre-Calc

    A hot-air balloon is floating above a straight road. To estimate their height above the ground, the balloonists simultaneously measure the angle of depression to two consecutive mileposts on the road on the same side of the balloon. The angles of

    asked on March 23, 2012
  57. math

    Points $D$, $E$, and $F$ are the midpoints of sides $\overline{BC}$, $\overline{CA}$, and $\overline{AB}$, respectively, of $\triangle ABC$. Points $X$, $Y$, and $Z$ are the midpoints of $\overline{EF}$, $\overline{FD}$, and $\overline{DE}$, respectively.

    asked on March 3, 2015
  58. chemistry

    Treatment of gold metal with BrF3 and KF produces Br2 and KAuF4, a salt of gold. Find the mass of the gold salt that forms when a 73.0 -g mixture of equal masses of all three reactants is prepared.

    asked on November 2, 2010
  59. physics

    A tennis ball with a speed of 12.5 m/s is moving perpendicular to a wall. After striking the wall, the ball rebounds in the opposite direction with a speed of 11.4 m/s. If the ball is in contact with the wall for 0.0139 s, what is the average acceleration

    asked on May 20, 2013
  60. Science

    How do global positioning systems use elevation points on Earths system to find latitude and longitude A. By using signals from a network of satellite B. By using topographic maps C. By using satellite images D. By using photography

    asked on May 19, 2017
  61. Statistics

    If my p-value = .322 and my significant level is .05 , then My Null Hypothesis is rejected and I must accept the Alternative hypothesis My Null Hypothesis is not rejected My Alternative hypothesis becomes the new Null Hypothesis I cannot make a decision

    asked on June 15, 2010
  62. Chemistry

    Calculate ΔG∘ at 298 K for the following reactions. Ca(s)+CO2(g)+12O2(g)→CaCO3(s) 2KClO3(s)→2KCl(s)+3O2(g) CO(g)+H2O(g)→H2(g)+CO2(g)

    asked on May 18, 2014
  63. physics 1

    In coming to a stop a car leaves skid marks 92m long on the highway. Assuming a decceleration of 7.00m/s^2, estimate the speed of the car just before braking.

    asked on September 13, 2010
  64. Physics

    Our sun rotates in a circular orbit about the center of the Milky Way galaxy. The radius of the orbit is 2.2 1020 m, and the angular speed of the sun is 1.2 10-15 rad/s. (a) What is the tangential speed of the sun? m/s (b) How long (in years) does it take

    asked on March 6, 2008
  65. clemson

    A farmer wants to make three identical rectangular enclosures along a straight river, as in the diagram shown below. If he has 1680 yards of fence, and if the sides along the river need no fence, what should be the dimensions of each enclosure if the total

    asked on October 6, 2014
  66. Physics

    A small disk of radius R1 is mounted coaxially with a larger disk of radius R2. The disks are securely fastened to each other and the combination is free to rotate on a fixed axle that is perpendicular to a horizontal frictionless table top. The rotational

    asked on December 2, 2011
  67. chemistry

    Given overall reaction: P4 + 10Cl2 ---> 4PCl5 Delta H for the reaction = ? PCl5 -----> PCl3 + Cl2 Delta H = +157 kJ P4 + 6Cl2 ----> 4PCl3 Delta H = -1207 kJ Calculate the Delta H for the overall reaction.

    asked on March 31, 2016
  68. Physics

    A truck driver slams on the brakes and skids to a stop through a displacement of delta x. (a) IF the truck has twice the mass, by what factor does the stopping distance change? 1) 0.25 or 2) 1 or 3) 4 (b) If the initial velocity of the truck were halved,

    asked on February 25, 2008
  69. Calculus

    Find the number a such that the line x = a divides the region bounded by the curves x = y^2 − 1 and the y-axis into 2 regions with equal area. Give your answer correct to 3 decimal places.

    asked on January 22, 2016
  70. Calculus

    For a cylinder with a surface area of 90, what is the maximum volume that it can have? Round your answer to the nearest 4 decimal places. The volume of a cylinder is πr^2*h and the surface area is 2πrh+2πr^2.

    asked on November 4, 2015
  71. chemistry

    Determine the percentage composition of each of the following compounds a) NaCl b) AgNO3 c) Mg(OH)2

    asked on March 13, 2008
  72. Computers

    The Command Prompt found on Windows 10 is very similar to the interface of what past operating system?

    asked on March 21, 2019
  73. World history

    Which temporary solution was adopted in 1924 to address the economic problems caused by Germany's inability to make reparations? A-Versailles plan B-Marshall plan C-Dawes plan D-young plan B?

    asked on July 13, 2018
  74. physic

    A long straight horizontal wire carries a current = 3.90 A to the left. A positive 1.00 C charge moves to the right at a distance 1.50 m above the wire at constant speed v = 5000 m/s. What is the magnitude of the magnetic field at the location of the

    asked on March 8, 2012
  75. science

    How many kilograms of NH3 are needed to produce 1.00 x 10^5 kg of (NH4)2SO4?

    asked on May 23, 2012
  76. Physics

    An elevator in a tall building is allowed to reach a maximum speed of 3.3 m/s going down. What must the tension be in the cable to stop this elevator over a distance of 3.4 m if the elevator has a mass of 1330 kg including occupants?

    asked on October 14, 2010
  77. chemistry

    Some distilled water is added to an empty beaker. A gram of copper(II) nitrate is added to the beaker with stirring. After a few minutes, what is in the beaker? a. solid copper(II) nitrate and water b. nitrogen gas, copper atoms, electrons, and water c. a

    asked on January 28, 2011
  78. Statistics

    Suppose a certain species bird has an average weight of xbar 3.40 grams. Based on previous studies, we can assume that the weights of these birds have a normal distribution with sigma 0.29 grams. Find the sample size necessary for a 98% confidence level

    asked on July 16, 2010
  79. Chemistry

    Calculate the pH of a solution at 25.0 °C that contains 1.94 × 10-10 M hydronium ions.

    asked on November 17, 2012
  80. Statistic

    A recent poll conducted by Gallup Inc. asked the following question: In general, how much trust and confidence to you have in the mass media - such as newspapers, TV, and radio - when it comes to reporting the news fully, accurately, and fairly? A great

    asked on September 26, 2016
  81. math

    Calculate the finance charge and new balance using the previous balance method. Previous balance = $179.32 Annual rate = 16% Finance charge = New purchases = $117.42 Payments/credits = $85.00 New balance =

    asked on June 14, 2010
  82. Fraction

    A girl spends 1/4 of her pocket money on monday and 3/8 on wednesday. What fraction of her money is left

    asked on November 3, 2014
  83. Math

    (8.86 + 1.0 * 10^-3) / (3.610 * 10^-3) Calculate the above formula, expressing the answer in scientific notation with the correct number of significant figures: 8.86 + 1.0 * 10^-3 = 8.86 + 0.0010 = 8.8610 = 8.86. 8.86/(3.610 * 10^-3) = 2454 2.454 * 10^3

    asked on January 9, 2015
  84. Calculus

    Sorry this is really long. Just wondering how I would do each of these A particle is moving with velocity v(t) = t^2 – 9t + 18 with distance, s measured in meters, left or right of zero, and t measured in seconds, with t between 0 and 8 seconds

    asked on February 14, 2016
  85. algebra

    in a relationship between variables, what is the variable called that changes in response to another variable? a. function b. input function c. independent variable d. dependent variable

    asked on November 9, 2017
  86. Calculus

    dy/dx=x/(x-4) I.will have a slope field with negative slopes in quadrant I II.will have a slope field with positive slopes in all quadrants III.will produce a slope field with columns of parallel tangents

    asked on February 18, 2016
  87. another question algebra

    write an explicit formula for the sequence 7,2,-3,-8,-13 then find a14

    asked on June 9, 2008
  88. Chemistry

    Explain the production of an emission spectrum in terms of the energy states of an electron. what does that mean someone help me please.

    asked on November 6, 2007
  89. physics

    As a protest against the umpire’s calls, a baseball pitcher throws a ball straight up into the air at a speed of 20.4 m/s. In the process, he moves his hand through a distance of 1.57 m. The acceleration of gravity is 9.8 m/s 2 . If the ball has a mass

    asked on February 15, 2015
  90. Chemistry

    Which of the following metals or nonmetals are expected to displace Mn or Cl (respectively) from MnCl2? 1. Ca should displace Mn. 2. Br should displace Cl. 3. Cu should displace Mn. 4. I should displace Cl.

    asked on September 22, 2013
  91. physics

    racing on a flat track, a car going 32 m/s rounds a curve 56m in radius. what is the car's centripetal acceleration?

    asked on December 1, 2010
  92. Physics

    A light beam strikes a piece of glass at a 60.00° incident angle. The beam contains two wavelengths, 450.0 nm and 700.1 nm, for which the index of refraction of the glass is 1.4824 and 1.4750, respectively. What is the angle between the two refracted

    asked on March 15, 2010
  93. chemistry proofread

    write the chemical equations for the following sentences a) Aluminum reacts with oxygen to produce aluminum oxide I put Al + O2 ----------> 2Al2O3 b) Phosphoric acid, H3PO4, is produced through the reaction between tetraphosphorous decoxide and water I put

    asked on March 26, 2008
  94. calculus

    No idea where to start The cost in dollars of producing x units of a particular camera is C(x) = x2 - 10000. (10 points) Find the average rate of change of C with respect to x when the production level is changed from x = 100 to x = 101. Include units in

    asked on December 16, 2014
  95. chemistry h/w help

    The concentration of lead nitrate (Pb(NO3 )2 ) in a 0.726 M solution is __________ molal. The density of the solution is 1.202 g/mL.

    asked on September 15, 2010
  96. Chemistry

    Calculate the percent ionization of 0.140 M lactic acid in a solution containing 8.5×10−3 M sodium lactate.

    asked on April 27, 2013
  97. Chemistry

    If a copper sample containing some zinc impurity is to be purified by electrolysis, the anode and the cathode must be which of the following? a. anode: pure copper cathode: pure zinc b. anode: pure zinc cathode: pure copper c. anode: pure copper cathode:

    asked on April 14, 2008
  98. Chemistry

    Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter. The heat of combustion of naphthalene is -40.1 kJ/g. When 0.8210 g of naphthalene was burned in a calorimeter containing 1,000. g of water, a temperature rise of

    asked on February 11, 2013
  99. Math

    Let f(x) be a polynomial such that f(cos theta) = cos(4 theta) for all theta. Find f(x). (This is essentially the same as finding cos(4 theta) in terms of cos theta; we structure the problem this way so that you can answer as a polynomial. Be sure to write

    asked on February 8, 2014
  100. math

    7. The tennis team is selling key chains as a fundraiser. If its goal is to raise is at least 180, how many key chains must it sell at $2.25 each to meet that goal? Write and solve an inequality. a. 2.25k (greater than or equal to) 180; k (greater than or

    asked on October 18, 2016