# Posts by Erin

Total # Posts: 717

1. ### Trig

Find the exact trigonometric function of cos(2a). hyp: 17 opp: 15 adj: 8
2. ### Trig

If tan a= 12/15, 0 degrees < a < 90 degrees, then find the exact value of each of the following: A. Sin a/2 B. Cos a/2 C. Tan a/2
3. ### Trig

The angular speed of a point on a planet is 3pi/7 radian per hour. The equator lies on a circle of radius approximately 9000 miles. Find the linear? velocity, in miles per? hour, of a point on the equator.
4. ### Trig

The seats of a Ferris wheel are 40 feet from the? wheel's center. When you get on the? ride, your seat is 6 feet above the ground. How far above the ground are you after rotating through an angle of 17pi/4?
5. ### Math

Jill said that an angle is made of any to rays is she correct explain
6. ### Math

Thank you so much Bosnian!!
7. ### Math

The length of the top of a work bench is 5 m greater than the width. The area is 66 m^2. Find the length and the width.
8. ### Math

The Coffee Counter charges ?\$11.00 per pound for Kenyan French Roast coffee and ?\$15.00 per pound for Sumatran coffee. How much of each type should be used to make aa 24 pound blend that sells for ?\$13.00 per? pound?
9. ### Math

In? 2009, a diabetic express company charged ?\$39.95 for a vial of type A insulin and ?\$30.49 for a vial of type B insulin. If a total of ?\$1446.64 was collected for 40 vials of? insulin, how many vials of each type were? sold?
10. ### Math

Three neighbors measure the snow in their yards over an entire winter. Manny has 30 inches of snow, Mo has 3.5 feet of snow, and Jack has 1.5 yards of snow. The neighbors want to pile all of the snow into one giant snow pile so they can have the most epic sledding hill ever. ...
11. ### Chem

Ooops did not mean to post this twice!
12. ### Chem

Calculate the enthalpy change in the reaction of H2 with F2 to produce HF. The H–H and F–F bond energies are 436 and 155 kJ/mol, respectively, and the H–F bond energy is 567 kJ/mol H2 (g) + F2 (g) --> 2HF (g)
13. ### Chem

Calculate the enthalpy change in the reaction of H2 with F2 to produce HF. The H–H and F–F bond energies are 436 and 155 kJ/mol, respectively, and the H–F bond energy is 567 kJ/mol H2 (g) + F2 (g) --> 2HF (g)
14. ### Stat 214

Three identical chips, each with 0 on one side and 1 on the other, are to be tossed simultaneously. A. writes the sample space. B. what is the probability of observing the sum of the face-up numbers to equal to 2? C. What is the probability of observing the sum of the face up ...
15. ### math

Suppose you put \$2000 in a savings account at an APR of 8% compounded quarterly. Fill in the table below. (Calculate the interest and compound it each quarter rather than using the compound interest formula. Round your answers to the nearest cent.) Quarter Interest Earned ...
16. ### Chemistry

A pediatrician prescribes the antibiotic amoxicillin to treat a child suffering from an ear infection. The prescribed dose is to be 72.1 mg of drug per kilogram patient body mass per day. The drug is to be administered twice each day in the form of a liquid containing 126.0 mg...
17. ### Chem

Suppose a runner completes a 10K (10.0 km) road race in 42 minutes and 15 seconds. What is the runner's average speed in miles per hour?
18. ### Social Studies

The constitution gave more power to the states
19. ### chemistry

if 5.76 grams of co2 forms when 4.00 grams of c2h6 reacts, what is the percent yield for 2c2h6+7o2=4co2+6h2o
20. ### Chemistry

How many grams of CaCl2 are needed to prepare 25.0 mL of .500 M solution? and What volume of 12.00 M HCL is needed to prepare 150.0 mL of .500 M HCL?

Calculate (triangle)H for the following gas-phase reaction: 2 H-C (3dashes) C-H + 5 O=O --> 4 O=C=O = 2 H-O-H -Using bond energies
22. ### Chem Help!!!

A 1.00 mL aliquot of solution A was diluted to 50.00 mL using 0.02 M Fe(III), forming solution B (reaction 2) By looking at this how many moles of sodium salicylate were in the 1.00 mL aliquot used to prepare solution B?
23. ### Chemistry

The spectrophometer was used to measure the absorbance of each of a series of [FeSa]+ solutions. A standard curve was construnceted by plotting the absorbance vs. concentration (M). The slope and y-intercept were found to be 1496 M-1 and .003, respectively. An aspirin sample ...
24. ### Chemistry

A tablet containing calcium carbonate and fillers with a mass of 1.631 g was dissolved in HCl. After the fillers were filtered out, the HCl was neutralized by adding sodium carbonate. The resulting precipitate was pure calcium carbonate (with the fillers removed). The solid ...
25. ### Chemistry

Given the reaction: Fe2SiO4 (s) + 2 H2CO3 (aq) ---> 2 FeCO3 (s) + H4SiO4 (aq) how many grams of Fe2SiO4 (s) are required to completely react with 55.0 mL of .500 M H2CO3 (aq) ?
26. ### Chemistry

Given the reaction: Fe2SiO4 (s) + 2 H2CO3 (aq) ----> 2FeCO3 (s) + H4SiO4 (aq). How many grams of Fe2SiO4 are required to completely react with 55.0 mL of .500 M H2CO3 (aq)?
27. ### Chem

Suppose a student diluted and titrated a bleach unknown exactly as described in the experimental procedure, except only a single titration was performed which required 16.22 mL of 0.100 M Na2S2O3. Calculate the number of moles of ClO- in the sample titrated.
28. ### Chemistry

How would I calculate the number of moles in CIO- from the sample titrated also?
29. ### Chemistry

Suppose a student diluted and titrated a bleach unknown exactly as described in the experimental procedure, except only a single titration was performed which required 16.22 mL of 0.100 M Na2S2O3. Calculate the number of moles of Na2S2O3 used in the titration.
30. ### Chem

Could you explain the second part more please?
31. ### Chem

Which of the following salts is water soluble? AlCl3, Li2SO4, BaC2O4, NaF, NiS, FeBr2, (NH4)2CO3, Zn(NO3)2, Na3PO4, Mg(OH)2, Ca(CH3CO2)2. Also specify the concentration of each ion in solution for the following: .10 M AlCl3 (aq) and .15 M (NH4)2SO4 (aq)
32. ### Chemistry

How many mols are there?
33. ### Chemistry

Assuming that the unknown acid sample in question 1 had a mass of 0.177 g, what is the molar mass of the unknown acid?
34. ### Chemistry

Suppose that 16.41 mL of 0.0512 M NaOH were required to titrate a sample of unknown acid. How many moles of NaOH were used?
35. ### Chemistry

We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15 mL. From this molarity and volume, the moles of NaOH can be calculated. Since the unknown acid is monoprotic, this ...
36. ### Grammar

But in my class we have to write our intro first and she yells at us for going further.
37. ### Grammar

Also my biggest similarity is how the state sets standards of what should be taught. But my two main differences are funding and how you have to be zoned for a specific school for public schools but no private.
38. ### Grammar

For right now I need help writing my intro paragraph. I also have to write a thesis and I do not understand how to do that.
39. ### Grammar

I am writing a compare and contrast essay between private school and public school can you help me write it
40. ### Chemistry

I believe the answer is 2.75grams of Oxygen Gas
41. ### Chemistry

The balanced equation for the synthesis of water is: 2H2 + O2 > 2H2O If I have 5.5 grams of water, at least how many grams of Oxygen gas was needed?
42. ### Chemistry

Iron (III) Oxide reacts with Aluminum to form Aluminum Oxide and Iron. If I have 255 g of Aluminum and unlimited Iron (III) oxide, how many grams of Iron will form? I am really not sure how to work with this. What does it mean when it says that the iron is unlimited, how would...
43. ### Geometry

Carlos is making cookies. The recipe calls for 1 cup of sugar for every 3 cups of flour. Carlos has only 2 cups of flour. How much sugar should Carlos use?
44. ### Math 160

The position function of an object moving along a straight line is given by s = f(t). The average velocity of the object over the time interval [a, b] is the average rate of change of f over [a, b]; its (instantaneous) velocity at t = a is the rate of change of f at a. A ball ...
45. ### pre calculus work

given f(x)= 5x+4/5x^2+4x and g(x) = 1/x a. determine the domains of f(x) and g(x) b. simplify f(x) and find any vertical asymptotes c. explain how the two functions differ I have absolutely no idea how to answer this question - can you please help me to figure it out?!
46. ### Health

_____are the result of an injury to a ligament DOMS Muscle sprain Muscle strain*** Overuse injury _______ Is the result of an injury to either a muscle or a tendon DOMS Muscle sprain*** Muscle strain Overuse injury
47. ### Health

a person can become dehydrated when wearing heavy clothing during aerobic exercise in warm weather true** false
48. ### Math

Well since I don't see the two triangles I can only use my imagination and take a guess. I would say square or rectangle
49. ### English

Read the following passage "I don't know anything," he said, "except that I'm beginning to be sorry we bought that room for the children. If children are neurotic at all, a room like that -" "It's supposed to help them work off their ...

thanks!
51. ### English

Against which American value did the Beat generation of writers react? equality freedom individualism traditionalism***
52. ### Math

You charge \$3.75 an hour for babysitting plus \$5 for fixing lunch. How much did you make last saturday ?
53. ### HUMAN DEVELOPMENT

The Seattle longitudinal study of cognitive development discovered that, among older people,
54. ### Physics

Don't forget that torque=I(alpha), so multiply mg sin(theta) and ma both by r so you'll be in the same units.
55. ### Maths lit,life science,agriculture,geograph

math is very lit btw
56. ### Maths lit,life science,agriculture,geograph

which what..?
57. ### science

the density of an object with a volume of 60.0 mL and a mass of 400.0g is___? a. 0.150g/mL b. 2.89g/mL c. 5.50 g/mL or d. 6.67 g/mL
58. ### Math

It's the the third link, it'll say "One-step addition & subtraction equations" I hope this helps.
59. ### Math

You have to do the opposite operation! It's a little confusing to write, so google this: " Khan Academy one step equation fraction " He's really easy to follow along with!
60. ### Social Studies

Thank you! I'll stick with the first two.
61. ### Social Studies

Choose two famous individuals to research that lived between 1820 and 1860. Keep in mind—your famous Americans MUST have DIFFERENT opinions on the SAME topic. Can you help me choose the two different individuals? Here's a list that I can choose from:  Andrew ...
62. ### Physics

An electron travels at a uniform speed of 2.50 × 106 m/s toward the top of this page. It then enters a uniform magnetic field and experiences a maximum force of 5.15 × 10-8 N that points toward the right of the page. What is the magnitude of the magnetic field? ...
63. ### Math

The laurelwood pta is presenting it's 5th annual talent show and Kate is collected tickets at the door the gym is filled with 215 students and adults. Students tickets are .50 and adults tickets are 2.00. If Kate collected 250.00. How many adults and how many students ...
64. ### social studies

so what are the real answers
65. ### Physics

A pilot flies out of Cleveland and sets his compass due North. He maintains an airspeed of 250 km/hr. After 30 minutes he finds that the plane is 200 km north and 40 km west of the starting point. What is the velocity of the wind? I've made my triangle and found the ...
66. ### English (EXTREMELY URGENT)

I gave up and guessed got it right and it was D

68. ### English (EXTREMELY URGENT)

Hip Hop Planet, James Mcbride, I think its A
69. ### English (EXTREMELY URGENT)

Please help he answer this one question. Which detail best describes why the author discusses the history of rap music. To show the extreme poverty of certain regions To explore the tension amongst certain cultural groups To expose events that are rarely discussed To give the ...

71. ### Precalculus

How many ancestors have you had in the six generations preceding you? (Assume no unusual circumstances such as duplicate ancestors.)
72. ### Statistics

It is estimated that heights of adult men are normally distributed with a mean of 70 inches and a standard deviation of 3.5. In one state, the law requires a person to be 68 inches or taller to become a fire fighter. (a) What proportion of adult men will meet this height ...
73. ### Physics

An Object of mass 7 kg is pushed along a surface up to a velocity of + 10 m/s before it is let go. It then slows to a stop due to an 11-N frictional force. How long until it comes to a stop?
74. ### Physics

A 15.0-g metal cylinder is placed on a turntable, with its center 73 cm from the turntable's center. The coefficient of static friction between the cylinder and the turntable's surface is μs = 0.79. A thin, massless string of length 73 cm connects the center of ...
75. ### Physics

A red colored ball tossed upward reaches a maximum height of 3.0m. show that the initial speed is 7.7m/s^2.
76. ### Math

\$38,000 loan, 60 month/ 5years, 7.5% rate, and the payments are made quarterly not monthly. How much are the payments going to be?
77. ### Phyics

A cylinder which is in a horizontal position contains an unknown noble gas at 4.63 × 104 Pa and is sealed with a massless piston. The piston is slowly, isobarically moved inward 0.202 m, while 1.95 × 104 J of heat is removed from the gas. If the piston has a radius...
78. ### Economics

Can someone please explain the difference between these, and how they apply to someone that has monotonic preferences? I have read in the book but they all seem to be running together and am so confused! Thank you. Symmetry Convexity Local Non-satiation Transitivity Completeness

Please check my answers! Thank you! Simplify the following expressions. Collapse “x” terms, and/or simplify fractions and exponents. 1.) (12/5) / (36/20) = 4/3 2.) x^13*x^3 = x^16 3.) x^4 / (x^2)^3 = 1/x^2 4.) x^-3 / x^2 = x^-5 5.) (x^2-8x+16) / (x-4) = x-4 6.) x^(-1...
80. ### Microeconomics

If the price elasticity of demand is 2, this means that a __________ increase in price causes a __________ decrease in quantity demanded. A. 15%; 100% B. 15%; 10% C. 20%; 40% D. 30%; 20% answer B 15%, 10%

Yes
82. ### math

Say if these numbers make a right triangle and a Pythagorean triple: 2, 2 square root 2, and 2 square root 3. I am confident that the answer for both parts of the question is no, because when 2 is squared and when 2 square root 2 is squared it is larger than 2 root 3 squared. ...
83. ### Psychology

Please Make Small Sounds. I like this one because it is related to language
84. ### Calculus 2 (Series - Convergent or Divergent?)

Can someone show me a step by step process and explanation how to solve this problem? 1) Consider the following series. (∞ on top of summation symbol) (k = 1 under the summation symbol) ∑ k(k+15)/(k+13)^2 Determine whether the series is convergent or divergent. If ...
85. ### Calculus 2

I need help in solving an initial-value problem and a few series problems (Especially on #45 & #46). I don't really understand how to do the series problems...majority of the time. An explanation would be great as well. Thank you for your time. #20) Solve the initial-value...
86. ### physics

When swimming across a river you swim to the east at 1.0 mph while the river flows southward at 2.4 mph. Your velocity is a superposition of these two velocities. What is your speed (i.e. the magnitude of your velocity)? i have no idea how to do this please help
87. ### physics

A box of books weighing 349 N moves with a constant velocity across the floor when it is pushed with a force of 434 N exerted downward at an angle of 37.9◦ below the horizontal. Find μk between the box and the floor.
88. ### Accounting

Can someone please tell me how to set this up? I tried doing (45+1.50 - 47) x 150 but I don't think this is right. thank you An investor in a Corporation. On January 1, Year One, purchased 150 shares of the corporation’s capital stock at a price of \$45 per share. On ...
89. ### math

The perimeter of a rectangle is 72. the length of the rectangle is twice the width. Find the dimensions of the rectangle.
90. ### math

192 fl oz=_ pt

b
92. ### College Algebra 1

What is the interval notation for -4(x+9)^3(x-11)^4(x+6)>0

thanks ^^^
94. ### physics

We're you able to solve this? I cant find the answer!
95. ### Calculus

Would you please check my answer to make sure I did it right? Bus travel, a bus company finds that monthly costs for one particular year were given by C(t) = 100 + t^2 dollars after t months. After t months the company had P(t) =1000 +t^2 passengers per month. How fast is its...
96. ### Math

1. Find the common ratio and the 7th term of the sequence 2/9, 2/3, 2, 6, 18, ..... 2. The 3rd and 5th terms of a geometric sequence are 2 and 1/2 respectively. What is the first term? 3. Find the geometric mean between: a. 1/2 and 1/3 b. sqrt5 - sqrt2
97. ### Math

Find the number of the sides of a regular polygon, if the measure of one of its exterior angle is between 28 and 32.
98. ### Math

If the measure of an interior angle of a regular polygon is 165, find the sum of the measures of its interior angles
99. ### Math

The sum of the measures of four of the angles of a heptagon is 520. Two of the remaining three angles are congruent. The other remaining angle is 3/2 the measure of one of the two congruent angles. Find the measures of the remaining angles.
100. ### Math

1. Victor brought a brand new car for 750,000. IF the value of the car depreciates 20% per year, what will it be worth during the fourth year? 2. Given the terms a10 = 3/512 and a15 = 3/16384 of a geometric sequence, find the exact value of the first term of the sequence.
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