Popular questions and responses by kelsey
  1. Chemistry

    Consider the decomposition of a metal oxide to its elements, where M represents a generic metal. M203(s)---> 2M(s) + 3/2 O2(g) info given for Gf(kJ/mol): M203= -10.60 M(s)=0 O2(g)= 0 1.) what is the standard change in Gibbs energy for rxn as written in

    asked on March 15, 2012
  2. Chemistry 101

    I don't remember my instructor going over this and the book isn't explaining it very well. Can anyone help answer these? Indicate the concentration of each ion or molecule present in the following solutions. 1. 0.30 M NaNO3 2. 1.5x10^-2 M MgSO4 3.

    asked on February 22, 2010
  3. Physics

    James Cameron piloted a submersible craft to the bottom of the Challenger Deep, the deepest point on the ocean's floor, 11,000 m below the surface. What was the total inward force on the 1.1-m-diameter pilot sphere in which Cameron sat?

    asked on August 21, 2018
  4. Math

    The time needed to complete a final examination in a particular college course is normally distributed with a mean of 83 minutes and a standard deviation of 13 minutes. Answer the following questions. What is the probability of completing the exam in one

    asked on October 22, 2015
  5. science help

    Every individual, including young people, can make decisions to use resources wisely. Use the terms reduce, reuse, and recycle to explain how the students in the image can help minimize solid waste.

    asked on May 19, 2014
  6. chemistry

    2H2O2 --- 2H2O + O2 is this a redox reaction if so what is the oxidized reactant and reduced reactant

    asked on August 26, 2010
  7. English answer check

    15. Which of the following sentences uses the passive voice? Almost every night Frances sang her son the same lovely lullaby. Because of the light color, Jason gave the room a second coat of paint. Have you ever been taken to the state fair? Despite her

    asked on May 2, 2012
  8. probability

    Betty has several of the standard six-sided dice that are common in many board games. If Betty rolls one of these dice, what is the probability that she rolls a three? use 3 decimal places.

    asked on March 27, 2016
  9. HELP MATH !!

    Melanie charges $4.50 per hour when she washes cars, plus $5.00 for supplies. Which function rule represents the amount y Melanie charges to wash cars for x hours? (1 point) a) y = 0.50x b) y = 4.50x + 5.00 c) y = 5.00x + 4.50 d) y = 9.50x The sale price

    asked on May 23, 2014

    Earth's energy sources include both renewable and nonrenewable resources. Name at least three sources of energy that could be used in your house.Then describe the ideal energy source for generating most of your home's electricity and explain why you chose

    asked on May 19, 2014
  11. math

    the function rule C = 10n + 26 relates the number of people n who attend a small concert to the cost in dollars C of the concert. Make a table of the input/output pairs to show the cost if 27, 39, and 43 people attend.

    asked on May 18, 2014
  12. Physics

    The density of gold is 19 times that of water. If you take a gold crown weighing 32 N and submerge it in water, how much upward force must you exert on the submerged crown to keep it from accelerating?

    asked on October 8, 2013
  13. physics

    The moon has a mass of 7.35 E 22 kg and is located 3.84 E 8 meters from the Earth. If Ellen, an earthling, has a mass of 47 kg, what is the gravitational force between Ellen and the moon?

    asked on April 21, 2010
  14. mathematics

    it takes 12 men to make 12 tables in 9 hours. how long will it take 8 men to make 32 tables?

    asked on October 16, 2010
  15. Econ

    Suppose that the U.S. government decides to charge wine consumers a tax. Before the tax, 10 billion bottles of wine were sold every year at a price of $4 per bottle. After the tax, 4 billion bottles of wine are sold every year; consumers pay $7 per bottle

    asked on October 11, 2015
  16. Math

    Starting from 105 feet away, a person on a bicycle rides towards a checkpoint and then passes it. The rider is traveling at a constant rate of 35 feet per second. The distance between the bicycle and the checkpoint is given by the equation d = 105 - 35t.

    asked on April 4, 2017
  17. precalculus

    A man is walking away from a lamppost with a light source h = 6 m above the ground. The man is m = 1.5 m tall. How long is the man's shadow when he is d = 11 m from the lamppost? (Hint: Use similar triangles.)

    asked on January 12, 2010
  18. Precalculus check answers help!

    1.) Find an expression equivalent to sec theta sin theta cot theta csc theta. tan theta csc theta sec theta ~ sin theta 2.) Find an expression equivalent to cos theta/sin theta . tan theta cot theta ~ sec theta csc theta 3.) Simplify (tan^2 theta +

    asked on May 30, 2012
  19. math

    What does a boy who likes to play with switches do?

    asked on November 30, 2011
  20. Chemistry

    How many liters of O2 gas, measured at 772 mmHg and 20 degrees C, are required to completely react with 2.4 mol of Al?

    asked on November 18, 2010
  21. Math

    How many posts does it take to support a fence around a square field measuring 200ft on a side if posts are placed every 20ft

    asked on August 27, 2017
  22. Geometry

    the angle of depression from D to F measures 40 degrees. If EF= 14 yd, find DE. round answer to nearest 10th

    asked on February 8, 2012
  23. Math

    Find the value of y for a given value of x, if y varies directly with x. If y = –252 when x = 84, what is y when x = 74?

    asked on September 1, 2012
  24. Physics help please**

    A water pipe having a 2.1 cm inside diameter carries water into the basement of a house at a speed of 0.88 m/s and a pressure of 169 kPa. The pipe tapers to 1.0 cm and rises to the second floor 7.1 m above the input point. (a) What is the speed at the

    asked on November 24, 2008
  25. Chemistry

    If 1.0L of spilled 1M HCl needed to be neutralized using solid sodium carbonate, how many grams of solid would be required? a)53g b)106g c)1060g d)530g

    asked on November 3, 2010
  26. Physics

    A bicyclist is coasting straight down a hill at a constant speed. The mass of the rider and bicycle is 55.0 kg, and the hill is inclined at 16.0° with respect to the horizontal. Air resistance opposes the motion of the cyclist. Later, the bicyclist climbs

    asked on October 25, 2011
  27. Science

    describe how the triassic period was a transitional time. during the mesozoic era explain why the boundary between triassic and jurassic period is similar to the boundary between Permian and triassic periods

    asked on November 12, 2014
  28. Health

    Regular exercise stimulates ___ which keeps the skeletal system moving to assist digestion and excretion. A.)peristalsis B.)urea C.)digestion D.)villi

    asked on February 18, 2015
  29. Physics

    A Nordic jumper goes off a ski jump at an angle of 10.0° below the horizontal, traveling 109.0 m horizontally and 44.0 m vertically before landing. (a) Ignoring friction and aerodynamic effects, calculate the speed needed by the skier on leaving the ramp.

    asked on September 18, 2013

    1. Which of the following quotations is the best example of a paradox? (1 point)“I’ll drain him dry as hay. . . ” “Lesser than Macbeth, and greater.” “So well thy words become thee as thy wounds. . . ” 2. Which of the following is an example

    asked on October 14, 2012
  31. chemisry

    Cd/Cd2+//H+/H2/Pt Write the oxidation and reductionhalf reactions. Sketch a possible deisgn cell. I am unclear on the Pt portion and the charges ?

    asked on August 30, 2010
  32. Physics help 2 please **

    A garden hose is attached to a water faucet on one end and a spray nozzle on the other end. The water faucet is turned on, but the nozzle is turned off so that no water flows through the hose. The hose lies horizontally on the ground, and a stream of water

    asked on November 24, 2008
  33. math help !

    3. Which function rule would help you find the values in the table ? n 2 4 6 m -8 -16 -24 A) m = -2n B) m = n - 2 C) m = n - 4 D) m = -4n 2. Explain how to write a function rule from the table below. Then write a function rule. x 2 4 6 y 1 0 –1

    asked on May 18, 2014
  34. Physics

    A speeding car is traveling at a constant 30.0 m/s when it passes a stopped police car. The police car accelerates at 7.0 m/s^2. a)how far will the police travel to catch up to the speeder? b) how fast will it be going when it catches up?

    asked on August 28, 2012
  35. Analytic Geometry

    Given two planes, discuss the methods used to determine if the planes are parallel, perpendicular, coincident, or none of these.

    asked on May 10, 2012
  36. math help !

    1. A rectangular prism has a width of 92 ft and a volume of 240 ft3. Find the volume of a similar prism with a width of 23 ft. Round to the nearest tenth, if necessary. a)3.8 ft3 b)60 ft3 c)15 ft3 d)10.4 ft3 2.A pyramid has a height of 5 in. and a surface

    asked on May 20, 2014
  37. Chemistrt

    I'm unsure of how to rearrange Balmer's equation to solve for n2. The equation is 1/lambda= R(1/2^2-1/n2^2)

    asked on May 27, 2017
  38. medical terminology

    Could someone please check my answers. If they are wrong could you give me the correct answer or tell me where to find it..Thanks in advance for all your help... 1. A patient has calculi present in the kidney. This statement indicates which diagnosis? A.

    asked on May 22, 2010
  39. physics

    A 1000 kg boat is traveling at 90 km/h when its engine is shut off. The magnitude of the kinetic frictional force f_k between the boat and water is proportional to the speed v of the boat: f_k = 70v, where v is in meters per second and f_k is in newtons.

    asked on August 30, 2010
  40. Math

    A gasoline tank is 1/6 full. When 21 liters of gasoline were added, it became 3/4 full. How many more liters more is needed to fill it?

    asked on June 21, 2018
  41. College Chemistry

    The density of a 0.0122 M KMnO4 is 1.037 g/mL. Suppose 26.35 g of 0.0122 M KMnO4 are required to titrate 1.072 g of a household H2O2 solution. a)Calculate the mL of MnO4^- added to reach the endpoint. b)Calculate the moles of MnO4^- added to reach the

    asked on February 25, 2014
  42. physics PLEASE!!

    A skateboarder starts at point A in Figure 8-27 and rises to a height of h = 2.37 m above the top of the ramp at point B. What was the skateboarder's initial speed at point A?

    asked on October 8, 2008
  43. Physics

    For chlorine gas, the van der Waals constants are: a = 0.658 J·m3/mol2, and b = 5.62 × 10-5 m3/mol. A 3.0-L tank contains 10.0 moles of chlorine gas at a temperature of 625 K. What is the pressure in the container? A) 15.0 MPa B) 17.3 MPa C) 13.5 MPa D)

    asked on September 9, 2015
  44. Physics

    Assume that all of the mass of a bicycle wheel is concentrated at its rim. Such a wheel of mass 1.2 kg and radius 30 cm starts from rest at the top of a hill 100m long and inclined at 20 degrees to the horizontal. What will be the speed of the wheel at the

    asked on March 25, 2014
  45. chemistry

    Determine the mass of carbon monoxide that is produced when 45.6 g of methane, ch4 react with 73.2 g of oxygen gas, o2. The products are carbon monoxide and water vapour

    asked on July 27, 2010
  46. Pre Calculus

    For a given right triangle, side a = 76.4 feet and side b = 39.3 feet. What is the measure of angle A to the nearest degree?

    asked on November 30, 2012
  47. physics

    The lead female character in the movie Diamonds Are Forever is standing at the edge of an offshore oil rig. As she fires a gun, she is driven back over the edge and into the sea. Suppose the mass of a bullet is 0.012 kg, and its velocity is +715 m/s. Her

    asked on November 9, 2011
  48. Physics

    Two children hang by their hands from the same tree branch. The branch is straight, and grows out from the tree trunk at an angle of 27.3° above the horizontal. One child, with a mass of 40.8 kg, is hanging 1.24 m along the branch from the tree trunk. The

    asked on November 16, 2011
  49. physics

    When an automobile moves with constant speed down a highway, most of the power developed by the engine is used to compensate for the mechanical energy loss due to frictional forces exerted on the car by the air and the road. If the power developed by the

    asked on March 10, 2010
  50. chem.

    How many grams of CO2 and grams of H2O are produced when 13.0g C2H2?

    asked on April 25, 2011
  51. Physics.

    A block of mass 3m is placed on a frictionless horizontal surface, and a second block of mass m is placed on top of the first block. The surfaces of the blocks are rough. A constant force of magnitude F is applied to the first block. a) Identify the

    asked on October 16, 2012
  52. chemistry

    How many grams of O2 are required to burn 13.0g of acetylene?

    asked on April 25, 2011
  53. chemistry

    I have posted this once and still cannot get the correct answer. Determine the mass of carbon monoxide that is produced when 45.6 of methane, CH4, react with 73.2 g of oxygen , O2. The products are carbon monoxide and water vapour.

    asked on August 3, 2010
  54. physics help 2!!

    When a pitcher throws a curve ball, the ball is given a fairly rapid spin. A 0.15 kg baseball with a radius of 3.7 cm is thrown with a linear speed of 41 m/s and an angular speed of 37 rad/s. Assume that the ball is a uniform, solid sphere. Calculate how

    asked on October 18, 2008
  55. science help !!

    1. Why is California’s high-speed rail such a groundbreaking effort? 2. Why will it take so long to complete the high-speed rail route?

    asked on May 21, 2014
  56. physics

    car P travels due East along a straight highway at a constant speed of 30m/s. at 9:00am , P passes Exit 17. At precisely the same moment, car Q passes Exit 16, traveling due West as constant 26m/s. Slightly later, car P and car Q pass the same point.

    asked on May 22, 2013
  57. Social studies

    an early board game in which players moved their counter around the squares?????? Thank you for using the Jiskha Homework Help Forum. Have you investigated the Egyptian sites Bob Pursley gave you this morning? I listed them for someone else on that site.

    asked on April 9, 2007
  58. physics PLEASE!!

    A 63 kg skier encounters a dip in the snow's surface that has a circular cross section with a radius of curvature of 12 m. If the skier's speed at point A in Figure 8-25 is 7.9 m/s, what is the normal force exerted by the snow on the skier at point B?

    asked on October 8, 2008
  59. Physics

    A speeding car is traveling at a constant 30.0 m/s when it passes a stopped police car. The police car accelerates at 7.0 m/s^2. a)how far will the police travel to catch up to the speeder? b) how fast will it be going when it catches up?

    asked on August 28, 2012
  60. chemistry

    What is the density (in g/L) of hydrogen gas at 23.0 degrees Celsius and a pressure of 1670 psi?

    asked on November 3, 2009
  61. pre calculus

    For a given right triangle, side a = 400 feet and side b = 900 feet. What is the measure of angle B to the nearest degree?

    asked on November 30, 2012
  62. Chemistry

    The reaction of fluorine with ammonia produces dinitrogen tetrafluoride and hydrogen fluoride. 5 F2(g) + 2 NH3(g) N2F4(g) + 6 HF(g) (a) If you have 73.7 g NH3, how many grams of F2 are required for complete reaction? b) How many grams of NH3, are required

    asked on January 27, 2011
  63. Physics

    An astronaut with a mass of 90 kg (including spacesuit and equipment) is drifting away from his spaceship at a speed o f.2 m/s with respect to the spaceship. The astronaut is equipped only with a 0.5 kg wrench to help him get back to the ship. With what

    asked on November 13, 2016
  64. Math

    Identify the sequence as arithmetic. geometric, or neither.. explain your answer 1.6, 0.8, 0.4, 0.2....

    asked on May 23, 2014
  65. pre calculus

    For a given right triangle, angle A = 61± and side b = 39 feet. What is the length of side a to the nearest foot?

    asked on November 30, 2012
  66. Precalculus check answers help!

    7.) Write the equation 3x + 4y – 7 = 0 in normal form. 3/5x + 4/5y + 7/5 = 0 -3/5x - 4/5y - 7/5 = 0 -3/5x - 4/5y + 7/5 = 0 ~ 3/5x + 4/5y - 7/5 = 0 8.)Write the standard form of the equation of a line for which the length of the normal is 4 and the normal

    asked on May 30, 2012
  67. Chemistry

    If your heating generates soot on the bottom of the crucible, what is the origin of the soot? How will this soot collection affect x?

    asked on February 23, 2014
  68. PLEASE!!

    At the local playground a child on a swing has a speed of 2.14 m/s when the swing is at its lowest point. (a) To what maximum vertical height does the child rise, assuming he sits still and "coasts"? Ignore air resistance. (b) To what maximum vertical

    asked on October 8, 2008
  69. math

    6. Kevin wants to calculate the value of the expression below. Which shows an equivalent way Kevin could write this expression? - 17 + 3 a) - (17 + 3) b) - (17 - 3) c) (- 3 + 17) d) ( - 3 - 17)

    asked on May 23, 2014
  70. pre calculus

    For a given right triangle, side a = 76.4 feet and side b = 39.3 feet. What is the length of side c to the nearest tenth of a foot?

    asked on November 30, 2012
  71. interest

    Perry has an opportunity to put $12,000 into an investment with an APR of 5.6% compounded annually. How long will it take his investment to double? (round to one decimal place)

    asked on April 10, 2016
  72. chemistry

    Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=? J/mol*K deltaS(surr)=? J/mol*K deltaS(univ)=? J/mol*K My answer is: deltaS(sys)=654.9J/mol*K

    asked on March 14, 2012
  73. physics

    A fish takes the bait and pulls on the line with a force of 2.7 N. The fishing reel, which rotates without friction, is a cylinder of radius 0.048 m and mass 0.76 kg. (a) What is the angular acceleration of the fishing reel? ? rad/s2 (b) How much line does

    asked on October 23, 2008
  74. Physics

    Calculate the total entropy change hat occurs when 2kg of lead at 40 degrees celcius are placed in a very large quantity of water at 10degrees celcius. the specific heat of lead is 0.031 cal/g K).

    asked on September 10, 2015
  75. Chemistry

    Sulfuric acid can dissolve aluminum metal according to the following reaction. 2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H2(g) Suppose you wanted to dissolve an aluminum block with a mass of 24.4g . What minimum amount of H2SO4 in grams would you need?

    asked on March 24, 2015

    Choose one destination that is represented by a flag. Write a paragraph about the effects of climate change in that destination.

    asked on May 22, 2014
  77. math (calculus)

    A rectangular sheet of paper of width a and length b, where 0

    asked on October 29, 2011
  78. calculus

    A trough is 12 feet long and 3 feet across at the top. It ends are isosceles triangles with a height of 3 feet. If water is being pumped into the trough at 2.5 cubic feet per minute, how fast is the water level rising when the water is 1 foot deep?

    asked on October 15, 2011
  79. physics

    (a) What is the tangential acceleration of a bug on the rim of a 6.0 in. diameter disk if the disk moves from rest to an angular speed of 79 rev/min in 5.0 s? m/s2 (b) When the disk is at its final speed, what is the tangential velocity of the bug? m/s (c)

    asked on March 27, 2010
  80. Algebra

    Consider the graph of the equation y=ax^2+bx+c, when a does not equal 0. If a is multiplied by 3, what is true of the graph of the resulting parabola? (A) The Vertex is 3 units above the vertex of the original. (B) The new parabola is wider than the

    asked on May 14, 2009
  81. physics

    A car initially traveling at 31.0 m/s undergoes a constant negative acceleration of magnitude 2.00 m/s2 after its brakes are applied. (a) How many revolutions does each tire make before the car comes to a stop, assuming the car does not skid and the tires

    asked on March 27, 2010
  82. Physics

    Two identical heavy metal spheres are released from the same height. Sphere 1 is at rest, and sphere 2 has a velocity of 10 m/s in horizontal direction.

    asked on September 16, 2013
  83. Math Help..!

    A stock's price dropped from $63.28 per share to $27.45. What was the loss on a single share of the stock?

    asked on October 27, 2014
  84. Physics

    A solid cylindrical disk has a radius of 0.18 m. It is mounted to an axle that is perpendicular to the circular end of the disk at its center. When a 40-N force is applied tangentially to the disk, perpendicular to the radius, the disk acquires an angular

    asked on November 22, 2011
  85. physics

    A brass ring of diameter 10.00 cm at 19.9°C is heated and slipped over an aluminum rod of diameter 10.01 cm at 19.9°C. Assume the average coefficients of linear expansion are constant. (a) To what temperature must the combination be cooled to separate

    asked on April 25, 2010
  86. Chemistry

    I have the answer to this question but the book does not explain WHY this is a good buffer solution? It uses pH=pKa - log(base/acid) and shows 7.2=7.2 - log(1). I don't understand why they can only use pKa7.2 and ignore the pKa 12.7. You are instructed to

    asked on June 21, 2016
  87. Physics

    A box weighing 600 N is pushed along a horizontal floor at a constant velocity with a force of 250 N parallel to the floor. What is the coefficient of Kinetic friction between the box and the floor?

    asked on October 13, 2010
  88. Physics

    The blades of a fan running at low speed turn at 200 rpm. When the fan is switched to high speed, the rotation rate increases uniformly to 340 rpm in 5.92 s. (a) What is the magnitude of the angular acceleration of the blades? (b) How many revolutions do

    asked on December 11, 2010
  89. Finance

    You just acquired a mortgage in the amount of $249,000 at 6.75% interest, compounded monthly. Equal payments are to be made at the end of each month for 30 years. How much of the first loan payment is interest? (Assume each month is equal to 1/12 of a

    asked on February 14, 2015
  90. History

    Which of these was a consequence of the Civil War? A- General William Tecumseh Sherman's March to the Sea destroyed Southern transportation lines. B- President Lincoln's Gettysburg Address persuaded the South to disarm and surrender. C- Maryland became a

    asked on October 27, 2019
  91. physics

    A rubber ball filled with air has a diameter of 25.1 cm and a mass of 0.618 kg. What force is required to hold the ball in equilibrium immediately below the surface of water in a swimming pool? I tried using the equation B = density(fluid)volume(object)g B

    asked on April 17, 2010
  92. physcs

    A potter's wheel having a radius 0.55 m and a moment of inertia 11.6 kg·m2 is rotating freely at 55 rev/min. The potter can stop the wheel in 8.0 s by pressing a wet rag against the rim and exerting a radially inward force of 66 N. Find the effective

    asked on April 17, 2010
  93. math

    1. Gina wrote this system of linear equations: 2x + y = 7 4x + 5y = 11 Which of the following shows the first four steps that Gina could have used to correctly solve this system for x? a) y = 7 – 2x 4x + 5(7 – 2x) = 11 4x + 25 – 10x = 11 25 – 6x =

    asked on May 23, 2014
  94. pre-algebra

    1.write the fraction 5/6 as a percent. Round to the nearest hundredth of a percent where necessary. 33.33% 66.67% 83.33% 1.20% 2. Chris and five of his friends go out to dinner. The total bill comes to $124.29. they decide to leave a 20% tip. Each person

    asked on November 14, 2013
  95. math

    Magnus purchased a car for $35,865. It depreciates about 3.6% each year. What is the value of the car after ten years?

    asked on November 30, 2012
  96. physics help please!!**

    A typical GPS (Global Positioning System) satellite orbits at an altitude of 4.0 107 m. (Astronomical data needed for this problem can be found on the inside back cover of the text.) (a) Find the orbital period of such a satellite. hours (b) Find the

    asked on October 30, 2008
  97. chemistry

    A 37.0 g mass of a metal was heated to 100°C and then plunged into 74 g of water at 24.0°C. The temperature of the resulting mixture became 28.0°C. (a) How many joules did the water absorb? (b) How many joules did the metal lose? (c) What is the heat

    asked on April 27, 2014
  98. math

    write an equation of an ellipse: Major axis 12 units long and parallel to the y-axis, Minor axis 8 units long, center at (-2,5)

    asked on April 1, 2012
  99. physics

    a baseball (m = 153 g) approaches a bat horizontally at a speed of 41.0 m/s (92 mi/h) and is hit straight back at a speed of 45.8 m/s (102 mi/h). If the ball is in contact with the bat for a time of 1.05 ms, what is the average force exerted on the ball by

    asked on November 9, 2011
  100. Finance

    After deciding to buy a new car, you can either lease the car or purchase it on a 3-year loan. The car costs $32,000. The lease offer is for $450/month for 36 months, with only $99 due up front. If you buy the car with a 3-year loan, the APR is 7% with

    asked on February 15, 2015


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