rebecca

Most popular questions and responses by rebecca
1. math

Find the area of the regular polygon. Round your answer to the nearest tenth. the individual sides are 10 the radius is 13.07

2. Chemistry

A voltaic cell utilizes the following reaction: 2Fe3+(aq)+H2(g)→2Fe2+(aq)+2H+(aq). What is the emf for this cell when [Fe3+]= 3.70M , PH2= 0.95atm , [Fe2+]= 7.0×10−4M , and the pH in both compartments is 4.05? Express your answer using two significant

3. Chemistry

Given the following half-reactions and associated standard reduction potentials: AuBr−4(aq)+3e−→Au(s)+4Br−(aq) E∘red=−0.858V Eu3+(aq)+e−→Eu2+(aq) E∘red=−0.43V IO−(aq)+H2O(l)+2e−→I−(aq)+2OH−(aq) E∘red=+0.49V

4. Algebra help??!!

I'm really confused with sets, could someone please check my answer?? I just really don't want to get it wrong... You have two boxes of colored pens, The first box contains a red pen, a blue pen, and a green pen, The second box contains a yellow pen, a red

5. Language arts

You meet Tock and Hambug in Act I of The Phantom Tollbooth. In Act II, you see them in action and hear more of what they have to say. How are the two characters alike? How are the two characters different? What do they do to help Milo? tell two ways for

There are 12 questions on an examination, and each student must answer 8 questions including at least 4 of the first 5 questions. How many different combinations of questions could a student choose to answer?

7. Chemistry

You can purchase hydrochloric acid in a concentrated form that is 37.0 hcl by mass and has a density of 1.20g/mL. Describe how exactly you would prepare 2.85 L of 0.500 M HCL from the concentrated solution.

1) The first step in the decision-making process is to brainstorm all possibilities (my answer) evaluate the result act realize there is a problem 2) Evidence that you have accomplished a goal is an example of which step in the SMART goal method? specific

9. Science

A blue-eyed man, both of whose parents were brown-eyed, marries a brown-eyed woman whose father was blue-eyed and whose mother was brown-eyed. This man and woman have a blue-eyed child. What are the genotypes of all these individuals?

10. Math

A construction crew wants to hoist a heavy beam so that it is standing up straight. They tie a rope to the beam, secure the base, and pull the rope through a pulley to raise one end of the beam from the ground. When the beam makes an angle of 40 degrees

11. math

If is a line whose equation is y = 2x- 1, find the equation of the image of under each of the following translations:(x, y) S (x +3, y)

12. Math

Kevin has 18 unit cubes. How many different rectangular prisms can be built using all the cubes

13. Chemistry

How many grams of H2O are required to react with excess CaC2 to produce 23.0 g of C2H2 according to the following equation? CaC2 + 2H2O -> Ca(OH)2 + C2H2 a.4.5 b.15.9 c.31.8 d.1.766 I think this equation works out by multiplying 2 moles by the molar mass

14. Chemistry

Hello! I really need help with this. Name the following salts according to the old -ic, -ous system and the stock system. a. CrS b. Cr2O3 c. CrI3 X 6H20 d. CuCl e. CuI2 f. CuBr2 x 4H20 g. HgCl2 h. Hg2Cl2 i. Fe (OH)3 I am totally lost. I don't know how to

15. Critical thinking

I'm having trouble rewriting the ambiguous sentences. I have answered them but i'm not sure that they are right. 2. Please close the door behind you. My answer: Please close the door that is behind you. 3. we heard that he informed you of what he said in

16. Chemistry

How many grams of SO3 are produced when 20 g FeS2 reacts with 16g O2 according to the balanced equation? 4FeS2(s)+15 O2(g)>>>2Fe2O3+8SO3(g)

17. Chemistry

The degradation of CF3CH2F (an HFC) by OH radicals in the troposphere is first order in each reactant and has a rate constant of k=1.6×108M−1s−1 at 4∘C. If the tropospheric concentrations of OH and CF3CH2F are 8.1×105 and 6.3×108 molecules cm−3,

18. math

The first ancient olympic games were held in 776 b.c. the ancient games were abolished in 393 a.d. The first modern olympics were held in 1896 a.d. a) How many years were there between the firstancient games and the year they were abolished? b) How many

19. Maths

Find the sum of the following series: 1024 - 512 + 256 - 128 +...+ 1 So a = 1024, r = -0.5, but I need to know what n is in order to use the formula. So I tried ar^(n-1) which is: 1024(-0.5)^n-1 = 1 but I don't know how to find n from there. Thanks in

20. poetry

"If Whales Could Think On Certain Happy Days" by Irving Layton As the whale surfaced joyously, water spouted from his head in great jets of praise for the silent, awesome mystery he beheld between sea and sky. Thankfulness filled his immense body for his

21. Social Studies

Who's job is it to line up the votes of the members of the party that holds the most seats in a chamber? A) president pro tempore B) Speaker of the house C) Minority whip D) majority whip **** The president of the Senate also serves as the _____? A) Head

Transportation Strike Disrupts Westridge Thousands unable to get to work or school WESTRIDGE, Ohio—More than 600 transportation employees went on strike at midnight last night after the Westridge City Council rejected their demand for a 10% pay increase.

23. AP Chemistry

A 2.685 g sample of KHC8H4O4 was dissolved in water and uses to standardize a NaOH solution. The endpoint was reached after 38.25mL of titrant were delivered. Find the molar concentration of the NaOH solution.

24. english

what are some poetic devices used in the following poem? "Mending Wall" by Robert Frost Something there is that doesn’t love a wall, That sends the frozen-ground-swell under it And spills the upper boulders in the sun, And makes gaps even two can pass

25. density

Suppose two worlds, each having mass M and radius R, coalesce into a single world. Due to gravitational contraction, the combined world has a radius of only 3/4R. What is the average density of the combined world as a multiple of p0, the average density of

26. math againn (converting decimals)

Write 6.4% as a decimal and as a fraction. Write 2 and one fourth as a decimal and as a percent. To convert from percent to decimal simpoy divide by 100. 6.4% = 0.064. To convert to fraction (do you want a mixed fraction or not? and percent or not?). For a

27. Biology I

Charles Darwin- Evolution? 2) Where does variation occur within an organism that causes evolution? 5) What is the main source of evidence for evolution? 6) What was the occupation that Darwin was originally studying for? 8) What did Darwin believe about

28. 11Science

A diploid organism has five pairs of chromosomes in each somatic cell. Assuming that no crossing over occurs, how many genetically distinct gametes can this organism produce?

29. Science

In witch type of symbiotic relationship is one organism helped while another organism is neither benefited nor harmed?

30. Physics (algebra-based)

A child holds a candy bar 13.4 cm in front of the convex side-view mirror of an automobile. The image height is reduced by one fifth. What is the radius of curvature of the mirror? Answer in units of cm. I did 1/5=-image distance (i)/13.4-->i=-2.68

31. Math

Nissan Appliances bought three dozen camcorders at a cost of \$5,040. The markup on the camcorders is 30% of the selling price. What was the original selling price of each camcorder?

32. Math

The entire can needs to be painted, including the top and bottom. If the diameter of the lid (x) is 5 cm, and the height of the can (y) is 9 cm, what is the approximate total surface area that will need to be painted?

33. Physics

How much power is required to lift a 25kg box to the top of a 4 meter flight of stairs in 3.5 seconds

34. chemistry

What is the explanation for the discrete lines in atomic emission spectra?

35. English

Is this paragraph’s main idea stated or implied? The greatest gift the Sumerians gave the world was the invention of writing. The Sumerians were a wealthy people. They needed some way to keep track of what they owned. They began drawing pictures. They

36. math

The perimeter of the small square is one-third the perimeter of the large square. What are the side lengths of the squares? small square side = x large square side = x + 2

37. Math

The admission to a local fair is \$10 for an adult and \$6 for a child. Each ride costs \$1.50 for and adult and \$1 for a child. Write an expression that represents how much more an adult will spend.

38. physics

A daredevil decides to jump a canyon of width 12 m. To do so, he drives a motorcycle up an incline sloped at an angle of 14.2◦. The acceleration of gravity is 9.8 m/s2 . What minimum speed must he have in order to clear the canyon? Answer in units of

39. Gr10 math

A rectangular lawn measuring 8m by 4m is surrounded by a flower bed of uniform width. The combined area of the lawn and the flower bed is 165m^2. What is the width of the flower bed?

40. History

which term suits this sentence: --------- often led to corruption, as some officeholders helped themselves to public money. Fill in the blank with one of these terms: labor unions, Grover Cleveland, Patronage, Chester Arthur, wealthy men, or James Garfield

41. math

A ball is shot straight up into the air with initial velocity of 45 ft/sec. Assuming that the air resistance can be ignored, how high does it go?

42. conclusions

What function do conclusions serve in essays? A. Conclusions provide the supporting details of an essay. B. Conclusions develop the main idea of an essay. C. Conclusions sum up the main idea of an essay. (MY ANSWER) D. Conclusions introduce new ideas

43. Chemistry

The radius of a chromium atom is 125 pm. How many chromium atoms would have to be laid side by side to span a distance of 4.14 mm?

44. 11Biology

What are the gametes formed by the following squash plants, the genotypes of which for fruit colour and shape given; and what will be the appearance of the offspring from each cross? WWdd x wwDD WwDD x wwdd WwDd x WwDD WwDd x Wwdd WwDd x wwdd WwDd x WwDd

45. Chem

Name the following binary compounds consisting of two nonmetals or a metalloid and a nonmetal. 1. AsH3= arsine 2. AsF5= arsenic pentafluoride 3. HCL= Hydrogen chloride is this right?

46. Chemistry

The molar enthalpy of vaporization for water is 40.79 kJ/mol. Express this enthalpy of vaporization in joules per gram.

47. math

1. A flywheel is rotating at 7 rad/sec. It has a 15-cm diameter. What is the speed of a point on its rim, in cm/min? 2. A wheel is rotating at 3 radians/sec. The wheel has a 30 cm radius. What is the speed of a point on its rim, in m/min? 3. What is the

48. Astronomy

Suppose that you travel to a planet that has 4 times the Earth's mass and 4 times the Earth's radius. Calculate how much more or less you would weigh on this planet compared to your weight on Earth. Express your answer as a factor or fraction of your

49. AP Chemistry

A 0.250 M NaOH solution was used to titrate a 19.75 mL HI solution. The endpoint was reached after 32.95 mL of titrant were delivered. Find the molar concentration of HI in the original solution.

50. science

Why might a plastic rod that contains a large number of electrons not have a static charge?

51. AP Chemistry

A 0.2500 M NaOH solution was used to titrate a 16.85 mL hydrofluoric acid solution. The endpoint was reached after 31.20mL of titrant were added. Find the molar concentration of hydrofluoric acid in the original solution.

Which of the following is a true statement about writing introductions of rough drafts? A. Do not worry about the central point of your essay; it will happen later on as you revise your paper. (MY ANSWER) B. Pay close attention to the correct spelling of

53. Rational Functions

Write an equation for a rational function whose graph has the following properties: x-intercept of 3 y-intercept of -3 vertical asymptote of x=-2 horizontal asymptote of y=2

54. Chemistry

How much heat energy, in kilojoules, is required to convert 63.0g of ice at −18.0 ∘C to water at 25.0 ∘C ?

55. math

a student in Greece discovers a poetry bowl that contains 28% of its original amount of c-14

56. Biology HELP

How would the production of gelatinase help a pathogen be more virulent?

57. AP Chemistry

A 0.500 M HNO3 solution was used to titrate a 21.15 mL KOH solution. The endpoint was reached after 22.30 mL of titrant were delivered. Find the molar concentration of KOH in the original solution.

58. Physics

In a car crash, Car A rear ends Car B that stopped at a red light. After the crash, Car A and Car B meld together moving at a speed of 14 m/s. Car A has a mass of 1750 kg. Car B has a mass of 2000 kg. Calculate the initial momentum of Car A. So far I have

59. Physics

A 1.0kg mass weighs 9.8 Newton on earth's surface, and the radius of Earth is roughly 6.4 x 10 to the power of 6. The mass of the earth is 6.02 x 10 to the power of 24. Calculate the average density of Earth?

60. PHYSICS

A water pistol aimed horizontally projects a stream of water with an initial speed of 5.00 m/s. (a) How far does the water drop in moving 1.00 m hori- zontally? (b) How far does it travel before dropping a vertical distance of 1.00 cm?

61. AP Chemistry

A 30.75 mL sample of 0.450 MKOH was titration with an unknown concentration of HCl. The endpoint was reached when 29.35 mL of NaOH were delivered. Find the concentration of the titrant

62. chemistry

what is the name for the compound Al2I3??

63. Algebra

I have a few questions on my Pre- Algebra Pre- test. I am in 7th grade. Anyone willing to help me for a few questions for 5-10 minutes?

64. Statistics

assume that adults have IQ scores that are normally distributed with a mean of 105 and a standard deviation of 15 find the probability that a randomly selected adult has an IQ between 89 and 121 ?

65. Medical

Can some one please tell me all the: adjectives adverbs conjunctions nouns prepositions pronouns verbs - in this paragraph? please! Thank you. The patient was brought to the operating room and Bier block anesthesia was performed. The right upper extremity

Using Hubble's law, determine the recessional velocity of a galaxy 700 Mly away. Use 22 km/s/Mly for the Hubble's parameter. Show your work for full credit

67. Physics

A phonograph record initially moving at 33 1/3 rpm accelerates uniformly to 45 rpm in 2.5 s. What is the angular distance traveled by the record during this time?

68. Math

A company producing steel construction bars uses the function R(x) = -0.06x²+10.2x -50 to model the unit revenue in dollars for producing x bars. For what number of bars is the revenue at a maximum? What is the unit revenue at that level of production?

69. chem

What is the pH of 1.00 L of the buffer solution that contains 0.100 M HF and 0.120 M NaF after 0.020 mol of HNO3 is added? The Ka of HF is 3.5×10−4, and so pKa = 3.46.

70. History

Which of the following statements most accurately analyzes how the Philadelphia Convention shaped the new national government?

71. Physics-mechanics

Find the speed and period of a satellite that orbits Mars 175 km above it's surface. (The average radius of Mars is 3.40 x 10^6; and it's mass is 6.42 x 10^23. Use all necessary formulas and show all clear-working, to enable me understand how you arrived

72. History

1) Which of the following best describes Affirmative Action? a) It was a way to fight corruption within the US government. b) The actions taken to instill new anti immigration laws. c) Of solving economic and educational discrimination. d) Of solely

73. Finance

Brown Enterprises’ bonds currently sell for \$1,025. They have a 9-year maturity, an annual coupon of \$80, and a par value of \$1,000. What is their current yield? 7.80% 7.90% 9.00% 9.10% 9.20%

74. CHEMISTRY

IS THIS RIGHT? Name the following binary acids: HF(aq) – Hydrofluoric Acid HCl (aq)– Hydrochloric Acaid H2Se(aq) – Hydroselenide Acid HBr(aq) – Hydrobromic Acid HI (aq)– Hydroiodic Acid H2Te (aq)- hydrotelluric acid

75. Physics-mechanics

Find the speed and period of a satellite that orbits Mars 175 km above it's surface. (The average radius of Mars is 3.40 x 10^6; and it's mass is 6.42 x 10^23. Use all necessary formulas and show all clear-working, to enable me understand how you arrived

76. Psychology

What is an example of romantic love, fatuous love and consummate love? ex. Infatuation would be one night stand

77. chemistry

using VSEPR THEORY explain why 1)BF4- is a tetrahedral molecule 2)SF3+ is a Trigonal pyramidal molecule 3)ICI4- IS A SQUARE PLANER molecule 4IF5 IS A SQUARE pyramidal molecule 5)PF5 IS A TRIGNAL BIPYRAMIDAl molecule help Dr bob222

78. math

1.A flywheel is rotating at 7 rad/sec. It has a 15-cm diameter. What is the speed of a point on its rim, in cm/min? 2.A wheel is rotating at 3 radians/sec. The wheel has a 30 cm radius. What is the speed of a point on its rim, in m/min? 3.What is the

79. History

How did the legal opinion of John Marshall shape the US government?

80. physics

A solid sphere of radius 35 cm is positioned at the top of an incline that makes 20 ◦ angle with the horizontal. This initial position of the sphere is a vertical distance 3.4 m above its position when at the bottom of the incline. The sphere is released

81. Chem

Suppose the water sample has a relatively high percent of volatile solid material. How would this have affected the reported mass of: a. dissolved solids -- too high, too low, or unaffected? Explain. TDS will be unaffected b. total solids -- too high, too

82. 11Science

How many genetically different gametes can be produced from a diploid cell with seven chromosome pairs?

The earth rotates on its axis once every 24 hours. How long does it take Earth to rotate through an angle of 4(pi)/3?

84. Astronomy

The average distance between the Earth and the Sun is called the astronomical unit (AU), which is about 150 million km (1.5 x 108 km). Jupiter is 780 million km from the sun. a) How far is Jupiter from the sun in astronomical units (AU)? b) Based on your

85. History

Why did Ho Chi Minh lead a resistance against France? a) He sought Vietnam’s independence. b) He wanted to control the country. c) He wanted more foreign influence and control other than France. d) He desired to keep French rulers in the Vietnam but

86. World Civilization

1. In 1789, the National Assembly revoked the privileges of the aristocracy. This occurred in reaction to A. a peasant uprising. B. Louis XVI's withdrawal of troops from Paris. C. discontent among the poor people of Paris. D. the storming of the Bastille

87. poetry

in the poem the legend by garrett hongo what is the aullusion at the end of the poem in stanza 4? Need Answer ASAP!!

88. science

Why might a plastic rod that contains a large number of electrons not have a static charge?

89. AP Chemistry

A 0.3500 MHCl solution was used to titrate a 21.60 mL sodium acetate solution. The endpoint was reached after 25.75 mL of titrant were added. Find the molar concentration of sodium acetate in the original solution.

please help!! I have no idea how to do these I am trying to help my son.. Find two mixed numbers so that the sum is 21 1/6 and the difference is 4 3/6?

91. physics

A ray of light goes through the centre of a semicircular glass disk, n = 1.58, and onto a wall (x = 19.4 cm, y = 5.06 cm). What is the incident angle, θ?

92. History

One major concern people had was that --------- were controlling politics at the expenseof the public good. Fill in the blank with one of these terms: Labor unions, Grover Cleveland, Chester Arthur, wealthy men, or James Garfield. I think that it is either

93. novel study

If anyone had read the giver, could they please tell me 2 scenes i could draw between chapters 11-15? thanks :)

94. chemistry

calculate the mass of sodium hydroxide needed to prepare 500 mL of a 0.10 M solution.

95. College Algebra

Solve the system of equations with ROWOPS program. I know how to do the first step but after that it gets difficult for me, this is the system of equations: 3x + y - z = 1 x + 2y - z = 0 2x - y + z = 4 I used to be able to do these but now I'm getting a

96. social studies

Say during the civil war the southhad the same amount of people as the north. Would they south win?? Probably not. The South didn't have the industries, the money, or the moral imperative to win the Civil War. During the American Civil War, the determining

97. Physics

A skier with a mass of 66.6 kg starts from rest and skis down an icy (frictionless) slope that has a length of 58.4 m at an angle of 29.8° with respect to the horizontal. At the bottom of the slope, the path levels out and becomes horizontal, the snow

98. Calculus 2

Sketch the region enclosed by y=e^2x, y=e^6x, and x=1. Decide whether to integrate with respect to x or y. Then find the area of the region.