# kelsey

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

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.

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?

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

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.

6. ## chemistry

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

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

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.

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

10. ## HELP I DON'T UNDERSTAND THIS QUESTION !

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

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.

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?

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?

14. ## mathematics

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

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

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.

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.)

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 +

19. ## math

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

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?

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

22. ## Geometry

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

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?

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

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

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

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

28. ## Health

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

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.

30. ## ENGLISH

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

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 ?

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

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

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?

35. ## Analytic Geometry

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

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

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)

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.

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.

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?

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

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?

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)

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

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

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?

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

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

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

50. ## chem.

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

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

52. ## chemistry

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

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.

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

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?

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.

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.

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?

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?

60. ## chemistry

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

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?

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

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

64. ## Math

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

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?

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

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?

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

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)

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?

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)

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

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

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).

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?

76. ## SCIENCE HELP !!

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

77. ## math (calculus)

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

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?

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)

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

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

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.

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?

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

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

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

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?

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

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

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

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

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

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 =

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

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?

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

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

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)

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