# Questions Asked onFebruary 22, 2012

1. ## chemistry

At a given temperature, you have a mixture of benzene (vapor pressure of pure benzene = 745 torr) and toluene (vapor pressure of pure toluene = 290 torr). The mole fraction of benzene in the vapor above the solution is 0.590. Assuming ideal behavior,

2. ## Physics

In a game of basketball, a forward makes a bounce pass to the center. The ball is thrown with an initial speed of 4.3 m/s at an angle of 15 degrees below the horizontal. It is released 0.80m above the floor. What horizontal distance does the ball cover

3. ## Physics

An astronaut is inside a rocket that is blasting off vertically from the launch pad. You want this rocket to reach the speed of sound (331 m/s) as quickly as possible, but you also do not want the astronaut to black out. Medical tests have shown that

4. ## science

a =vf-vi/t is the equation for calculating the acceleration of an object. Write out the relationship shown in the equation, using words.

5. ## chem11

Suppose you have a large supply of sponge balls with weights in the centre, so that when the balls are piled on each other the bottom ones are flattened. Sketch a graph that generally describes mass vs. volume for these sponge balls. Also, would weighted

6. ## algebra

A cylinder has a radius of 4x + 2 and a height of 5x + 4. Which polynomial in standard form best describes the total volume of the cylinder? Use the formula v = pi r^2 h for the volume of a cylinder.

7. ## Physics

In a water park, people walk a distance of 20 meters up an inclined ramp before getting on a water slide. If the spot from where they start sliding down is located 7 meters above the water’s surface, calculate the angle of the ramp with the horizontal.

8. ## Chemistry

If 150.0 grams of iron at 95.0 degrees Celcius, is placed in an insulated container containing 500.0 grams of water at 25.0 degrees Celcius, and both are allowed to come to the same temperature, what will that temperature be? The specific heat of water is

9. ## geometry

Assume triangle JKL is in the first quadrant, with the measure of angle K = 90°. Suppose triangle JKL is a 30°-60°-90° triangle and segment JK is the side opposite the 60° angle. What are the approximate coordinates of point L? j(2,7) k(2,2) a(4.9,2)

10. ## Physics

Three identical charges of 2.0 uC are placed at the vertices of an equilateral triangle, 0.15m on a side. Find the net force acting on each angle.

11. ## Physics

A train moving at a constant speed on a surface inclined upward at 10.0° with the horizontal travels a distance of 400 meters in 5 seconds. Calculate the vertical velocity component of the train during this time period.

12. ## physics

A "swing" ride at a carnival consists of chairs that are swung in a circle by 12.0 m cables attached to a vertical rotating pole, as the drawing shows. (θ = 61.0°) Suppose the total mass of a chair and its occupant is 196 kg. the tension is 3961.97N Find

13. ## Physics

Two water jets are emerging from a vessel at a height of 50 centimeters and 100 centimeters. If their horizontal velocities at the point of ejection are 1 meter/second and 0.5 meters/second respectively, calculate the ratio of their horizontal distances of

14. ## Math

Assume that there are 7 different issues of Newsweek, 8 different issues of Time, and 4 different issues of Sports Illustrated, including the December 1st issue, on the rack. You choose 4 of them at random. What is the probability that you choose at least

15. ## Physics

A ball is ejected to the right with an unknown horizontal velocity from the top of a pillar that is 50 meters in height. At the exact instant, a carriage moving on rails is also released to the right from the bottom of the pillar. Calculate the velocity

16. ## physics

A ball is released from a tower at a height of 100 meters toward the roof of another tower that is 25 meters high. The horizontal distance between the two towers is 20 meters. With what horizontal velocity should the ball be imparted so that it lands on

17. ## Precalculus

A wheel rolling at a constant speed has a radius of 15 inches and takes 30 seconds to roll 100 feet along the ground. What is its angular velocity? Use 3.14 for pie, and solve to two decimal places.

18. ## Physics

If the vertical component of velocity for a projectile is 7.3 meters/second, find its hang time. A. 1.9 seconds B. 2.5 seconds C. 5.6 seconds D. 6.7 seconds E. 7.1 seconds

19. ## physics

A point charge with a charge of q1=2.60uC is held stationary at the origin. A second point charge with charge q2=-4.70uC moves from the point. x=0.140m, y=0 to the point x=0.230m, y=0.290m How much work is done by the electric force on q2?

20. ## Chemistry

What mass of oxalic acid dihydrate , H2C2O4•2H2O, is required to prepare 220.0 ml of a 1.28 M solution of oxalic acid ?

73. ## Macro econ

How might a “perfect” macro equilibrium be affected by (a) a stock market crash; (b) the death of a president; (c) a recession in Canada; (d) a spike in oil prices?

74. ## geometry

The perimeter of parallelogram CDEF is 54 centimeters. Find the length of segment FC if segment DE is 5 centimeters longer than segment EF. (Hint: Sketch and label a diagram first.) a)14 b)44 c)16 d)11

75. ## math

Joes electric made 19 customer calls last week and 24 calls this week, How many calls must be made next week in order to maintain an average of at least 21 calls per week for the three week period?

76. ## Physics

A thin condicting spherical shell of outer radius 20cm carries a charge of +3 muC. Sketch (a) magnitude of the electric field E and (b) potential V versus the distance r from the center of the shell.

77. ## Science

Why is only one egg produced during oogenesis while four sperm are produced during the parallel process of spermatogenesis?

78. ## physics

A girl delivering newspapers covers her route by traveling 10.00 blocks west, 4.00 blocks north, and then 5.00 blocks east.

79. ## Chemistry

Using the "octet rule" write the Lewis formulas for NF3 and NO3-.

80. ## Honors Physics

A lumberjack (mass = 98 kg) is standing at rest on one end of a floating log (mass = 290 kg) that is also at rest. The lumberjack runs to the other end of the log, attaining a velocity of +3.1 m/s relative to the shore, and then hops onto an identical

81. ## physics

A Chinook (King) salmon (Genus Oncorynchus) can jump out of water with a speed of 5.95 m/s. (See Problem 4.9, page 111 for an investigation of how the fish can leave the water at a higher speed that it can swim underwater.) If the salmon is in a stream

82. ## Chemistry

A student must prepare 2.00 L of 0.100 M Na2CO3 (106 g/mol) Which is the besst procedure for preparing this solution ?

93. ## Chemistry

What is the net ionic equation for the reaction that occures between nitrouse acid and strontium hydroxide ?

94. ## economics

Complete the following table for the firm below which is selling its product in a perfectly competitive market and hiring labor in a perfectly competitive labor market. MARGINAL WORKERS TOTAL MARGINAL PRODUCT REVENUE HIRED PRODUCT PRODUCT PRICE PRODUCT 1

95. ## probability

George has a bag of marbles. Inside the bag are 5 red marbles, 3 red marbles, and 2 blue marbles. He draws out two marbles in a row, without replacement. What is the number of outcomes?

96. ## physics

The string in the Figure is L = 135.0 cm long and the distance d to the fixed peg P is 94.5 cm. When the ball is released from rest in the position shown, it will swing along the dashed arc. How fast will it be going when it reaches the lowest point in its

97. ## Physical Science

If a hot iron ball is dropped into 200.0 gram of cooler waterthe water temperature increases by 2.0 celsius and the temperature of the ball decreases by 18.6 celsius. What is the mass?

98. ## Physics

When a 0.50 kg-object is attached to a vertically supported spring, it stretches 0.10 m from the equilibrium position. Find k for the spring.

99. ## physics

In preparing to shoot an arrow, an archer pulls a bowstring back 0.37 m by exerting a force that increases uniformly from 0 to 246 N. What is the equivalent spring constant of the bow?

100. ## physics

A racetrack has the shape of an inverted cone, as the drawing shows. On this surface the cars race in circles that are parallel to the ground, and the surface is at an angle θ = 25°. For a speed of 27 m/s, at what value of the distance d should a driver

101. ## chemistry

A water sample taken from the ocean is 36 ppt salt content. What is the mass of salt present in a liter of this ocean water? 36g

102. ## Physics

a small sphere whose m mass is 1.0 mg carries a charge q of 2.0*10^(-8)C. It hangs from a silk thread that makes an angle of 30 degrees with a large charged nonconducting sheet as in figure. Calculate the uniform charge density σ for the sheet

103. ## Trig (Last URGENT)

sin2x+cosx=0 , [-180,180) = 2sinxcosx+cosx=0 = cosx(2sinx+1)=0 cosx=0 x1=cos^-1(0) x1=90 x2=360-90 x2=270 270 doesn't fit in [-180,180) what do I do? Or maybe I did something wrong. sinx=1/2 x1=sin^-1(1/2) x1=30 x2=180-30 x2=150 is this correct? Please and

Two small charged balls have a repulsive force of 0.12 N when they are separated by a distance of 0.85 m. The balls are moved closer together, until the repulsive force is 0.60 N. How far apart are they now?

105. ## Physical Science

Balance this equation: I2+HNO3 = HIO3+NO2+H2O

106. ## math

Assume that the playbook contains 10 passing plays and 12 running plays. The coach randomly selects 8 plays from the playbook. What is the probability that the coach selects at least 3 passing plays and at least 2 running plays?

123. ## CHEM

Why are gamma rays generally not shown when writing nuclear equations ?

124. ## geometry

The surface area to volume ratio of a cube is 2 to 5. Find the length of each side.

125. ## pysics 1

You ride your bike along a straight line from your house to a store 1030 m away. On your way back, you stop at a friend's house which is halfway between your house and the store. a) What is your displacement? Tries 0/5 b) What is the total distance

126. ## algebra

you are planning a rectangular dining pavilion. its length is three times its width. you want a stone walkway that is 3 ft wide around the walkway. what should the dimensions of the pavilion be?

145. ## Psychology

The means of travel within and between neurons is different becuase: a. eletrial signals move impulses within the neuron, while chemical signals move the impulses between neurons. b. chemical signals move the impulses within the neuron, while electrical

146. ## chemistry

How many milliliters of 0.729 M NaOH are needed to prepare 150.0 mL of 0.122 M NaOH? 25.1 mL

147. ## trig

please help me with some questions I skipped on a review for our test coming up? solve 5-7 on the interval 0 greater than or equal to x less than or equal to 2pi. 5. sin x=sqrt3/2 6. cos x=-1/2 7. tan x=0 ---------------- 14. what is the exact value of

148. ## Science/geology

Why does the Red River flow north, and the Mississippi River flow south??

149. ## chemistry

A sample of a gas in a ridge container at 30.0 c has a volume of 2.00L. If its temp increased to 40.0 C What will the new volume be?

150. ## Physics

A satellite moves on a circular earth orbit that has a radius of 6.4 106 m. A model airplane is flying on a 23-m guideline in a horizontal circle. The guideline is parallel to the ground. Find the speed of the plane such that the plane and the satellite

151. ## Pre-Cal (polynomials)

How does the degree of a polynomial function affect the end behavior?

166. ## physics

A centrifuge is a device in which a small container of material is rotated at a high speed on a circular path. Such a device is used in medical laboratories, for instance, to cause the more dense red blood cells to settle through the less dense blood serum

167. ## algebra

if the fence around a rectangular field is 3000 feet,write a relationship for the length l of the field and its w.

168. ## chemestry

Calculate [OH^ - ] for strong base solution: 14.0 mL of 1.20×10−2 M Ca(OH)_2 diluted to 430.0 mL.

169. ## Chemistry

N2(g) + O2(g) --> N2O5(g) (a) Consider the unbalanced equation above. What is the maximum mass of N2O5 that can be produced when 43.0 g of N2 and 43.5 g O2 react?

170. ## Math

1. Start with an odd number, e.g. 3. Then the square of 3 can be expressed as the sum of two consecutive numbers, i.e. 32 = 9 = 4 + 5. Therefore the Pythagorean Triples are {3, 4, 5} since 32 + 42 = 52. Generate another set of Pythagorean Triples starting

171. ## math

sam spent a total of 5 2/3 hours doing homework. Julia spent 5 5/6 hours doing homework. who spent more time on homework this week? explain

172. ## geometry

leg xy of the right triangle is twice as long as leg yz. if the area of the triangle is 36cm to the second power what is the length icm of xy?

173. ## college physic

Liquid helium is stored at its boiling point temperature of 4.2K in a shperical container(r=0.30m).The container is a perfect blackbody radiator.The container is surrounede by a sherical shield whose temperature is 77k.A vacuum exists in the space between

174. ## Math

How long will it take for the population of a certain country to double if its annual growth rate is 3.9%

181. ## math

sam spent a total of 5 2/3 hours doing homework. Julia spent 5 5/6 hours doing homework. who spent more time on homework this week?

196. ## math

Factor completely: 36t^2 + 49 - 84t

197. ## Physics

suppose that the charge on the electron and proton did not have the same magnitude but instead differed by one part in 10^10. What would be the net charge on a 1.0 kg sample of helium gas?

198. ## statistics

Assume that IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Assume 1000 freshmen took the test.

199. ## chemistry

How many liters of 0.101 m NaCl contains 1.70 mol of this salt? Assume this solvent is H2O. Answer in units of L I do not understand what i am looking for or how to solve for it. Steps would be appreciated.

200. ## MATH

√5sec²x-2secx=5 i have to solve this equation on the interval [0, 2π).

201. ## Math

Simplify each expression. Write answers using positive exponents. a. (7x^2y^3)(-2xy) b. (a^2b^3)^-1(a^2b^3) c.(-4m^3)^2

202. ## Geometry

Use a paragraph proof to prove: if two lines and a transversal form corresponding angles that are congruent, then the two lines are parallel.

203. ## English

Could you please check if all the sentences are correct? Thank you. 1) To start with, I’ll have a tomato salad. I couldn’t help crying. I’m worried about Brian’s getting low marks at school. 2) He admitted eating all the biscuits. I couldn’t do

204. ## math

The 2000 Paralympics (Parallel Olympics) were held in Sydney, Australia. Ticket sales for all events totaled over 1.11 × 106. Of the total ticket sales, 8.84 × 105 were sold as day passes, and 2.24 × 105 were sold as reserve seating for the opening and

205. ## Physics(2)

A crane is holding a bloc of metal of 10 000kg. If the crane's arm weights 1000kg and is 10,0m long, what is the tension in cable a and how big is the force exerted on the pivot of the cranes arm. the cable passes through the top of the cranes arm and then

206. ## math

factor the trinomial. 1. m^2-7m-30 2. z^2+65z+1000 3.x^2-45x+450 4.d^2-33d-280

207. ## ENGLISH ESSAY

Could you plz help me to check if these two essays have thesis and thesis development? ESSAY 1:There has been much discussion over the maximum population capacity of our world today. This paper analyzes how agroecology has been a major benefit to society

208. ## Statistics

Find t-value for sample size n = 16 and area to the right 0.10

209. ## Algebra 1

1. m^2 - 7m - 30 2. z^2 + 65z + 1000 3.x^2 - 45x + 450 4.d^2 - 33 d - 280

210. ## computers

what is a link from one thing to another used to enhance usability? I say interface

211. ## computers

what would be redundant if added to the content of an e-mail? I say purpose of e-mail

212. ## math

Ayita has the coupon shown below Buy 10 or more quarts of paint and take $8 off your total order Ayita will buy 12 quarts of paint. Each quart of paint cost$10.95. Which number sentence can be used to find how much Ayita will pay for the paint if she uses

213. ## hcs/341

What are five recruitment strategies or methods..need to create a matrix. thanks..

214. ## Geometry

Shelly, Susan, and Samantha are all working at an amusement park for the summer. The manager finds out that one of them left the key in the door to the security office. When he asked them who did it, they replied: Shelly: Samantha did it. Susan: Shelly did

215. ## English

What is the past tense of run

216. ## APUSH help (ASAP)

Explain the rise of the republicans and the international challenges faced following world war I?

217. ## Algebra

Can you help me set this problem? it is as follows, "Find three consecutive odd integers such that their sum is 5 more than four times the larger."

218. ## Living ENvironment

In a hydrolysis reaction (enzyme) the bonds in substrate are weakened right always

Which of the following is NOT recommended when considering or accepting a job offer A- Make your acceptance contingent on a written offer. B- Accept the position immediately if you are offered the job at the end of the job interview C-Notify other

220. ## physical science

find the mass of sodium chloride formed when 6.9g of sodium burns in a gas jar filled with chlorine gas.

221. ## social study

What are some major turning point in vietnamese history leading up to world war 2

222. ## Calculus

a ladder is 20 feet long and its top is slidding at a constant rate of 2 feet per second. How fast is the bottom of the ladder moving along the ground when the bottom is 16 feet from the wall?

223. ## Math

Simplify each expression. Write answers in standard form. a. (4d-6)(-3d) b. 5g(g^2-2g+1) c. (-2q^2+q+3)-5(q^2+2q-1)

224. ## chemistry

a 0.25-g sample of a liquid was vaporized at 100 degree celcius. the vapor occupied 125ml under a presure of 0.96 atm. what is the molecular weight of the liquid?

225. ## statistics

Sample with size n = 100 has mean = 30. Assuming the population standard deviation is 8, construct 95% confidence interval for population mean.

226. ## chemistry

If 19.7 g of CaCl2 are present in 200 mL of aqueous solution, what is the concentration in terms of the following? a. molarity 100 M CaCl2 b. weight/volume percent 0.1 % (w/v) c. parts per thousand 100 ppt d. parts per million 10E4 ppm e. parts per billion

227. ## History

Why did Jame Otis oppose writ of assistance?

228. ## English

Here is the second exercise I'd like you to check. Thank you, Writeacher. 1.I am used to (read) __(reading)________till late. 2. The manager would like (speak) _(to speak)_________ to his secretary. 3. I remember (go) ___going_______ to primary school by

The interviewer wants to know why you got a D in all your English classes until this year, when you got a B. Your best response is A- “I had problems writing and never thought it was important. Then, I realized that it is important, so I got myself a

After the interview but before the job offer, it is NOT appropriate to A- phone the company you interviewed with. B-send a follow-up letter. C- inquire about the salary and benefits. D- respond to an e-mail query from the employer the answer is A OR B

231. ## geometry

The surface area of a right rectangular prism is 112 sq units. The height is twice the width. The length is 4 units more than the height . Find the volume.

232. ## division facts

If 44/4=11, what is 44/11? Explain?

233. ## Math

In a triangle the two larger angles differ by 10 degree. The smaller angle is 50 degree less than the largest angle. Find the measure of each angle. Just searching help on how to set it up.

234. ## US HISTORY

describe the Indian Removal Act of 1830

Today many employers expect interviewees to do more than just answer standard questions including all of the following except .defer to the hiring company to take control of the interview process B.provide samples of work they woukd likey do in the job.

236. ## Animal Behavior

If someone could give me an example of when developmental homeostasis works in an animal, and when it doesn't. Thanks!!!

237. ## Math

How to Generate Pythagorean Triples using an Odd Number 1. Start with an odd number, e.g. 3. Then the square of 3 can be expressed as the sum of two consecutive numbers, i.e. 32 = 9 = 4 + 5. Therefore the Pythagorean Triples are {3, 4, 5} since 32 + 42 =

238. ## Math

Landon is working one plans for a 12-acre housing development. A park will cover 2 1/2 acres, and paved areas will take 1 3/4 acres. How many acres are left for home sites??? Please show work, for how you did it

239. ## International Buisness

The marketing department is asked to formulate a strategy for disseminating product information on new drug Tigason. As the marketing manager what do you recommend?

240. ## math

in a survey of 375 people, one fifth of them chose pecan pie as their favorite dessert. To find the number of people who chose pecan pie as their favorite, you can multiply 375 by ____.

241. ## accounting

You notice that your accounts receivable days have doubled in the first six months of this year. Do you give the A/R Director a bonus or put him/her on probation? Why? Explain fully what questions you would ask the Director about the A/R and why it has

242. ## chemistry

Calculate the molarity of each. a. 1.50 mole of NaCl in 8.00 L of solution 0.188 M NaCl b. 270 mg of NaCl in 3.00 mL of solution 90 M NaCl

243. ## statistics

Sample with size n = 100 has mean = 30. Assuming the population standard deviation is 8, construct 95% confidence interval for population mean.

245. ## computers

what is it called when websites that look like legitimate sites are used to collect private information for malicious purposes? I say phishing

246. ## Organic Chemistry

Is there a systematic way to get all the boat conformations? I can get all of the chair conformation for, say, cyclohexanol, but can't figure out the boat conformations.

247. ## Math

Simplify each expression. Write answers using positive exponents. a. (7x^2y^3)(-2xy) b. (a^2b^3)^-1(a^2b^3) c.(-4m^3)^2

248. ## Math

Mr.Zhao sells lemons Lemons 1 for $1 or 12 for$6 Joseph wants to buy 27 lemons from Mr.Zhao. What is the least amount of money Joseph should have to pay him? A.$27 B.$24 C.$15 D.$12 C?

249. ## math

Mrs.Chavez is on an 8-kilometer hike. She wants to reach the halfway point of the hike in 3 hours. She plans to hike 1.5 kilometers the first hour and 1.5 kilometers the second hour. What could she do to determine how far she should hike in the third hour?

250. ## Physics

Consider a point charge with q= 1.5*10^-8 C. (a) what is the radius of an equpotential surface having a potential of 30 V?(b)Are surfaces whose potential differ by a constant amount (1,0 V) evenly spaced in radius?

251. ## Trigonometry (Help and Check)

Evaluate (exact answers): a) sin^-1(cos30) Need help. What do I do? b) sin[(cos^-1((sqrt2)/(2)))+[(sin^-1((sqrt2)/(2)))] = sin(45+45) = sin90 = 1 Is this correct? c) cos(arctan5/7) = 7/(sqrt74) = (7sqrt74)/74 Is this correct? Please and Thank you!

252. ## Trig Help (URGENT)

Solve over the indicated interval: 2sin^2x=sqrt2sinx , [-180,180) don't how to get x by itself please help and thank you

336. ## Math

how do you post 21/2 and 1 on a graph

337. ## maths

let f(x,y)=sqrt (1-x^2-y^2) where x^2+y^2

338. ## Calculus

Find the derivative of y = ln |cos(ln)|. I got -tan(ln x)/x, is this correct?

339. ## MATH !!!!!!!!!!

IN MR.MAROLE'S CLASS, THREE FOURTH OF THE STUDENTS TAKE MUSIC LESSONS.THAT IS, 15 STUDENTS TAKE MUSIC.HOW MANY STUDENTS ARE IN MR.MAROLE'S CLASS?

k/5+3/20

341. ## science

a car starts from a stop. at the end of 30 seconds its speed is 20 meters per second. what is the acceleration of the car?

342. ## us history ( 8TH)

at around 1832, was John C. Calhoun, Andrew Jason`s VP????

343. ## computers

forums and discussion boards are the same thing. I say true

344. ## writing

How would you feel if your teacher did not give you a present

345. ## social studies

How did religon affect social order in Sumer?

365. ## MATH

6.8M = HOW MANY CM

366. ## e-Commerce

If I opened a business and was offered \$1,000, should I sell or not? why? Cite the ethical dilemmas.

367. ## chemistry

what are three common ores from which copper can be extracted

368. ## algebra 2

solve the equation m^6 -64=0

2= 10+z/-3

370. ## politics?

what is gm bailout?

371. ## college algebra

what is 5/a-3b/a^2

2/7n+n=5/9

2/7n+n=5/9