# Questions Asked onFebruary 21, 2013

1. ## chemistry

the concentration of urea (MW=60.0g/mol) in a soltuion prepared by dissolving 16g of urea in 39g of H2O is ____ molal

2. ## Earth Science

Why is potassium-argon dating most applicable to dating very old rocks? potassium’s long half-life potassium’s short half-life argon’s long half-life argon’s short half-life

3. ## physics

An electron with speed = 2.54×10^7m/s is traveling parallel to an electric field of magnitude = 1.66×104 N/C. How far will the electron travel before it stops? How much time will elapse before it returns to its starting point?

4. ## Geology

How were divisions of time separated when scientists created the geologic time scale? by the thickness of rock strata by the color of rock strata by the fossils found in rock strata by the location of rock strata

5. ## Algebra 2 ..........

Solve for a and b in y=ab^x.

6. ## Statistics

Which of the following is an accurate description of Simpson's paradox? When groups of data are aggregated, an association can get stronger because of a confounding variable. That confounding variable is usually the number of observations in different

7. ## MAT222 Intermediate algebra

Solve a^1/2 / a^2

8. ## calculus

How is the integral of cos(2x) = sinxcosx?

9. ## Chemistry

How many grams of CS2(g) can be prepared by heating 12.9 moles of S2(g) with excess carbon in a 7.00 L reaction vessel held at 900 K until equilibrium is attained? Stoichiometry is 1 to 1

10. ## physics

A projectile is fired from the origin (at y = 0 m) as shown in the diagram. The initial velocity components are V0x = 310 m/s and V0y = 26 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q, which is 20 m

11. ## Chemistry

20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacity of the solution is 4.2JK-1. Find the

12. ## Chemistry

What is the ionic equation for (NH4)2CO3=2NH3+CO2+H2O

13. ## Physics2

"The heat engine uses 1.00x10^-2 mol of a diatomic gas as the working substance. Determine the temperatures at the 3 points." From 1-2, it's an adiabatic process and the constants are (P)(V^(7/5)) or (T)(V^(2/5)). From 2-3, it's an isobaric process with

14. ## art

visual art, what do i write for a 4 page paper on explaining the principle of design

15. ## Math

A major corporation is building a 4325 acre complex of homes, offices, stores, schools, and churches in the rural community of Glen Cove. As a result of this development, the planners have estimated that Glen Clove's population (in thousands) t yr from now

16. ## Physics

A cylindrical aluminum pipe of length 1.52 m has an inner radius of 2.20 10-3 m and an outer radius of 3.00 10-3 m. The interior of the pipe is completely filled with copper. What is the resistance of this unit? (Hint: Imagine that the pipe is connected

17. ## Physics

Two resistances, R1 and R2, are connected in series across a 15-V battery. The current increases by 0.050 A when R2 is removed, leaving R1 connected across the battery. However, the current increases by just 0.025 A when R1 is removed, leaving R2 connected

18. ## Chemistry

20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacityof the solution is 4.2JK-1. Find the

19. ## algebra

x-9+-6x+5 A. 14 B. 7 C. 2 D. 21 thanks for your help

20. ## Physics

A point charge Q1=−2 μC is located at x=0, and a point charge Q2=+8 μC is placed at x=−0.5 m on the x-axis of a cartesian coordinate system.The goal of this problem is to determine the electric field, E⃗ (x)=E(x)xˆ, at various points along the

21. ## Physics

A non-conducting ring of radius R with a uniform charge density λ and a total charge Q is lying in the yz - plane, as shown in the figure below. Consider a point P, located at a distance x from the center of the ring along its axis of symmetry. 1) What is

22. ## Physics

A flat thin non-conducting ring has an inner radius R1 and an outer radius R2 . The disk is uniformly charged with charge per unit area σ(>0) . (a) What is the electric field at the center, P, of the ring? Express your answer in terms of the following

23. ## Physics

A charge −Q is located at x=−l/2 and a charge +Q is located at x=l/2. Thus the separation between the two charges is l. (b)What is E(x) as a function of x for x>l/2? Express your answer in terms of, if necessary, Q, l, x and the constant ϵ0 (if

24. ## Physics

There are two conducting concentric hollow spheres of outer radii R2 and R1 (R2>R1). The thickness of the material of both spheres is d. The inner sphere is negatively charged with charge density −σ1. The larger sphere is positively charged with charge

25. ## Physics

There is a very large horizontal conducting plate in the x−y plane (consider it infinitely large). Its thickness is h. The charge densities on the upper and the lower surfaces are both equal to +σ. What is the magnitude of the electric field? Express

26. ## economics

What are the following variables used for in economics: Nominal GDP, Real GDP, GDP Deflator and CPI?

27. ## Math

A college freshman must take a science course, a humanities course, an elective course, and a mathematics course for the first term of the school year. If he or she may select any of the six science courses, any of the four humanities courses, any of the

28. ## Math

In selecting an ace, king, queen, and jack from an ordinary deck of 52 cards, how many ways can you choose if the cards must be of different suits? the same suit?

29. ## Math

A committee, which consists of two mathematicians and three scientists, will be formed from four mathematicians and six scientists. How many possible committees can be formed if : a. any of the mathematicians and scientists are included? b. one particular

30. ## Math

A box of jelly bears contains 52 jelly bears which 19 are white, 10 are brown, 7 are pink, 3 are purple, 5 are yellow, 2 are orange, and 6 are green. In how many ways can you select 9 pieces of candy at random from the box without replacement if 3 white

31. ## Chemistry

20cm3 of 0.500moldm-3 H2SO4 was consumed to neutralize 50cm3 of 0.400moldm-3 NaOH. The temperature of the system is increased by 36 degree C. The heat capacity of the calorie meter was 39 JK-1, and the heat capacityof the solution is 4.2JK-1. Find the

32. ## Chemistry

NH4NO3 is frequently used as a fertilizer and in explosive compounds dlta Hf values of this compound nd H20 are -365kJmol-1 and -286kJmol-1 respectively. Calculate the amount of heat released bye the dissociation of 1mol of NH4NO3 according to the

33. ## Chemistry

The molal boiling-point constant for water is 0.51 degrees C/molal. The boiling point of a 1.00 molal solution of Ca(NO3)2 should be increased by: A.) exactly 1.53 or B.) Somewhat less than 1.53 This is how I worked the problem: Ca(NO3)2 dislocates into 3

34. ## maths-urgently needed

show that: 2^5 cos^2a sin^4a = cos6a-2cos4a- cos2a + 2

35. ## math

name a figure that has an area of 47 centimeters square

So I have to do this project on simple machines. The invention we need to make should have at least 2 simple machines on it. We also have to draw it on posterboard and write a paragraph about it. One more thing is that it must make a person's life easier

37. ## maths

What is the total area bounded by the curve y^2(1-x) = x^2(1+x) and the line x = 1

38. ## chemistry

why is the graph of the meliting points of hydrocarbons not consistent?

39. ## Chemistry

What is the lewis dot structure for copper?

43. ## chemistry

the vapour pressure of 2.1%solution of non electrolyte in water at 100 degree celsius is 755 mm Hg.calculate the molar mass of the solute

68. ## chemistry

How many atoms are in 10.0 cm3 of mercury (at room temperature)?

69. ## algebra

How many rational numbers are there between 0 and 1?

70. ## maths-TRIGNOMETRY

show that: 2^5 cos^2a sin^4a=cos6a-2cos4a- cos2a + 2

71. ## English

I am doing a literary research paper on Romeo and Juliet. I don't know a topic. Any suggestions???

72. ## calculus

y= (x^3 - 2sqrx)/(x) y'=

73. ## Psychology/Biology Help!!

1) What memory system is sensation responsible for? Sensory, short term or long term memory system? Explain. 2) How does encoding memories relate to transfer appropriate processing and fluid intelligence?

74. ## Math

Kelsea has 6 coins. One-third of her coins are dimes. The value of the dimes is one-fourth the value of the coins. How much money does Kelsea have?

75. ## physics

a point charge of -4.00nc is the origin, and a second point charge of +6.00nc is on the x axis at x=0.800m. Find the magnitude and directin of the electric field at each of the following points on the x asix : a) x =20.0 cm b) x=1.20 m c) x = -20.0 cm

76. ## chemistry

How do you find q in q=mC delta t without the mass

77. ## Algebra

Which equation represents the axis of symmetry of the function y = –2x² + 4x –6? (1 point) y = 1 x = 1 x = 3 x = –3

78. ## Marketing

What are the strategies for entering into the global market? What are some strengths and limitations?. Do you know a company who has done well in a global economy?

79. ## Marketing

What lessons from McDonald’s success in the global marketplace are transferable across industries?

80. ## Math- geometry

Angles in a circle. Is the angle in the center equal to any other angle on the sides or top?

81. ## maths-Surface aea

if the radii of the circular ends of a conical bucket in the shape of frustum of a cone which is 45cm high are 28cm and 7cm.find the capacity of the bucket in litres

82. ## physics

Calculate the magnitude of the electric field at one corner of a square 1.48m on a side if the other three corners are occupied by 1.92×10−6 Ccharges.

83. ## science

How many elements are in glucose sugar, C6H12O6? How did you recognize them? a. How many total atoms are there in this equation?

84. ## science

What would be the equation for Drano which is made by combining Sodium Hydroxide NaOH and Water H2O?

85. ## physics

An electron with initial speed = 2.54×10^7 m/s is traveling parallel to an electric field of magnitude = 1.66×10^4 N/C .

86. ## physics

An electron with initial speed = 2.54×10^7 m/s is traveling parallel to an electric field of magnitude = 1.66×10^4 N/C . How far will the electron travel before it stops? How much time will elapse before it returns to its starting point?

87. ## science

How many atoms are in Zinc Chloride, ZnCl2?

132. ## Applied Calculus

Use differentials to approximate the quantity (give answer to 4 decimal places) 4th root of 256.6.

133. ## math

the product of 237 and 13

136. ## Economics

Ben deposits $5000 now into an account that earns 7.5 percent interest compounded annually. He then deposits$1000 per year at the end of the first and second years. How much will the account contain 10 years after the initial deposit?

137. ## biology help?

We anticipate the evidence gathered by you will indicate that three of the five species are in greater need of prioritising for conservation compared with the other two. You should start your account by very briefly explaining why these two species were

138. ## trig

Express sin4xcos3x as a sum or differences of sines and cosines

asked by Fabian onyango ndege
139. ## science

__________ do not have tissues and organs A. soft bodied animals b. sponges c. stinging- cell animals is a free-living worm parasitic?? and do tapeworms use food another animal eats???

140. ## science

The moon is the earth's nearest neighbor in space the radius of the moon is approximately one quarter of the earth's radius and it's mass is one eightieth of the earth's mass.(a)calculate the weight of an object with a mass of 50.0kg on the surface of the

141. ## math word problems

This year Jerry is half as old as his dad and 1/3 the age of his grandfather. If the sum of their ages is 132, how old is Jerry?

142. ## math

in traveling to Greece, Jim found the exchange rate to be 148 drachma equal to one American dollar. He bought 3 of the same priced items and spent almost 10 American dollars. What was the maximum amount of drachmas for each item?

143. ## music

Why is jazz considered to be "American" music?

144. ## English 4U

I need help coming up with a deductive syllogism (general to specific) The conclusion is: Therefore, driving age must be raised. I need a major and a minor premise for it...

145. ## Physics

A daredevil plans to bungee jump from a balloon 52.0 m above the ground. He will use a uniform elastic cord, tied to a harness around his body, to stop his fall at a point 15.0 m above the ground. Model his body as a particle and the cord as having

146. ## Calculus

On what values of x does the graph of f(x) = 2x^3 - 3x^2 + 12x + 87 have a horizontal tangent?

7y

148. ## Philosophy

1."Liberals need to understand the global health argument for abortion is deeply offensive. It is like fighting disease by killing everyone who has a disease" This contains: A. euphemism B. dysphemism C. rhetorical definition D. none of the above My answer

149. ## stats

in a battleground state 60 percent of all voters are republican. assuming there are only 2 parties, democrat and republican, if 2 voters are randomly selected for a telephone survey what is the probability that one is a republican followed by a democrat.

150. ## chemistry

"empirical formulas" combustion of a 0.255g compound conatining only C,H and O, yields 0.561g CO2 and 0.306g H2O. what is the empirical formula of the compound?

151. ## Chemistry

I had a quiz today and one of the multiple choice questions was something like, "find the final temperature of aluminum when it is cooled" and then it gave you the specific heat capacity of aluminum, the mass of the aluminum, initial temperature, and

152. ## Math plz fast i really need it

Archie rolls two number cubes each with sides numbered 1 through 6 he then finds the sum of the numbers on the tops of the cubes which two sums have the same probabillity? A. 3 and 4 B. 5 and 9 C. 5 and 8 D. 10 and 12 i need the work involved and i have

153. ## ELA

What is the opposite of extend?

154. ## algebra

i am having trouble understaing how to write these out in simplest form please help a. 7^3x7^2x8^5/ 8^4x7x8^-7 for this i got 7/8 b. (a^-2b^4c^3)2 can you explain and show me how to do this?

155. ## mechanics of materials

Select the correct answer.The change in length of a steel wire under an applied load can be halved by keeping all other conditions constant but using: A. A different material having a Young's modulus half that of steel B half the cross sectional area of

156. ## chem

For each of the following equilibria, use Le Chatelier's principle to predict the direction of reaction when the volume is increased. (a) C(s) + H2O(g) CO(g) + H2(g) (b) 2 H2(g) + O2(g) 2 H2O(g) (c) 2 Fe(s) + 3 H2O(g) Fe2O3(s) + 3 H2(g) a i put no change

157. ## chemistry

"empirical formulas" p 889(153e)

When a square of area 4 is dilated by a scale factor of k, we obtain a square of area 9. Find the sum of all possible values of k. I do not understand...it is not 3/2, as I was told, but I don't understand why? Help?

159. ## MATH PLZ

Which is true when a negative nuber is subtracted from a positve number? A.the difference is always 0 B.the difference is always positive C.the difference is always negative D.the difference could be negative or positive *i need examples to

160. ## Math

The eggplant ave. bus passes max's house every 8 mins. the cabb creek bus passes it every 12 mins. the last they passed by together was at 9:00 am. when will it happen again

161. ## mechanics of materials

an aluminium alloy bar with a Young's modulus of 70GPa is under a tensile stress of 10MPa, Which of thefollowing is the equal to the strain in the bar? A 0.0014 B 7.0x10raise to the power3 c 700 D 1.4x10 raise to the power -4

162. ## math $$The graph of 5x-2y=10 intersects the x-axis and y-axis what are the order pairs for these two points of intersection? A.(2,0) and (0,5) B.(2,0) and (0,-5) C.(-2,0) and (0,5) D.(-2,0) and (0,-5) asked by Angie 163. ## math$$

The graph of 5x-2y=10 intersects the x-axis and y-axis what are the order pairs for these two points of intersection? A.(2,0) and (0,5) B.(2,0) and (0,-5) C.(-2,0) and (0,5) D.(-2,0) and (0,-5)

221. ## Lang. Arts

2. Choose the option that corrects the sentence below. If the sentence is correct, select “d. The sentence is correct." Members of the Convention of 1836 a revolutionary group signed the Texas Declaration of Independence. A.Members of the Convention, of

222. ## college algebra

driving along a crowded freeway you notice that it takes a time to go from one mile marker to the next. when you increase your speed by 8.4 mi/hr the time to go one mile decreased by 14 seconds. What was your original speed?

223. ## english

Identify the correct sentence. a) Georgia wanted only to be loved, Dante wanted only to love her. b) Georgia wanted only to be loved and Dante wanted only to love her. c) Georgia wanted only to be loved Dante wanted only to love her. d) Georgia wanted only

224. ## American History

The English civil war affected the american colonies in which of the following ways: a.) With england convulsed in civil war, the mother country for a time failed to provide military protection to the colonies b.) Several colonies began to discuss forming

225. ## Calculus

On what interval is the function f(x)= x^3 - 3x^2 + 7x concave up?

226. ## MATH

Y^3+Y^2-4Y-4 AND T^2+4Z^2 THESE ARE FACTORING QUESTIONS CAN SOME ONE PLEASE SHOW ME THE STEP ON HOW TO SOLVE THESE TWO PROBLEMS

227. ## SI Units

fundamental SI units of: - a distance of exactly 26 miles - an area of 1.0 square root -the volume of a sphere of radius 1.40 picometers -a density of 38. tons per cubic furlong

228. ## chemistry

how many grams of nitrogen will react with 23 grams of oxygen

229. ## MATH

USE THE AC METHOD FACTORING 9+^2+5+-4 CAN SOME ONE SHOW ME THE STEP TO SOLVING THIS PROBLEM

230. ## Math Gr.12 (Calculus)

How do i do this? 3= 6x^2 - 2x -8

231. ## math

what is the rule for this in/out table? (4,-1), (5.-2), (6,-3), (7,-4) i need help ASAP

232. ## math

what is mental math?

233. ## math

pat has some t-shirts. 1/4 of the t-shirts are pink, 1/2 of the remainder are white and the rest are purple. what fraction of the t-shirts are purple?

234. ## math

pat has some t-shirts. 1/4 of the t-shirts are pink, 1/2 of the remainder are white and the rest are purple. what fraction of the t-shirts are purple?

235. ## geometry

Which type of angle do construction workers use when building to make sure that the walls and floors of a building are perpendicular

236. ## math

Trey keeps sports cards in 3 drawers. Each drawer contains exactly 120 cards. In each drawer 2/3, of the cards are baseball cards, and 1/3 of the cards are a mixture of football, hockey, baseball, and soccer cards. If Trey decides to trade 1/4 of his

237. ## Chemistry

How much concentrated solution would you take to prepare 2.80L of 0.475M HCl by mixing with water?

asked by M J
238. ## math

pat has some t-shirts. 1/4 of the t-shirts are pink, 1/2 of the remainder are white and the rest are purple. what fraction of the t-shirts are purple?

239. ## Math

So, if Tyler has to earn $50.00 in two weeks for a gift to a friend and has already earned$18.42 so far, what equation would you use to figure out how much more money he has to earn each week?

240. ## Chemistry

How much concentrated solution would you take to prepare 2.80L of 0.475M HCl by mixing with water? Hydrochloric acid is usually purchased in a concentrated form that is 37.0% HCl by mass and has a density of 1.20g/mL.

asked by M J
241. ## Math

A circle is divided into 18 equal parts. How many degrees is the angle for each part? How many degrees is the angle for 5 parts?

242. ## physics

what is the height of the ball if the bottom of the swing is zero, speed is 2.8m/sec, 9.81 acceleration of gravity

243. ## Science

Which of the following bonds is polar? A.F—F B.O—H C.O—O D.H—H I think it is B...?

249. ## organic chem

Classify as primary, secondary, tertiary alcohols. i. 2-butanol ii. 3-methyl-3-pentanol iii. 2-methyl-1-pentanol iv. 3-chlorocyclohexanol

250. ## physics

Calculate the magnitude of the electric field at one corner of a square 1.48m on a side if the other three corners are occupied by 1.92×10−6 Ccharges.

251. ## Math

How to compare 7/9 7/8 6/7

252. ## Geometry

What is the shortest distance from the point (2,1) to the line x-y= -1

253. ## organic chem

Dehydrate the following a. 2-methyl-1-propanol b. 2-methylcyclohexanol c. 2-methyl-1-phenyl-1-propanol d. 1-methylcyclopentanol

254. ## Math

Solve the differential equation. Let C represent an arbitrary constant. (Note: In this case, WebAssign expects your answer to have a negative sign in front of the arbitrary C.) (dz)/(dt) + e^(t+z) = 0

255. ## physics

A boy coasts down a hill on a sled, reaching a level surface at the bottom with a speed of 6.9 m/s. If the coefficient of friction between the sled's runners and snow is 0.045 and the boy and sled together weigh 580 N, how far does the sled travel on the

286. ## math question

Why is 6/8 not equivalent to 18/32 ??

287. ## Trigonometry

Write the trigonometric expression as an algebraic expression. 1.) SIN(ARCSIN X+ARCCOS X) ANSWER: 1 2.) SIN(ARCTAN 2X-ARCCOS X) ANSWER: 2x²-SquareRoot of 1-x²/Square Root of 4x²+1.

288. ## Composition

Revise the following paragraph, improving it without changing its overall meaning. Pay particular attention to sentence structure. Ever been assigned to work on a group project for class! Many students dread group projects: because one student typically

289. ## Physics

Plane flying southwest at 155mi/hr. their is a wind from the west at 45.0mi/hr. what's the planes new velocity

290. ## CONTACTS,CONFLICTS,AND THE CRUCIBLE

please help me thank you. What was the main reason for the isolation of Japan?. A. Domination by Chinese culture B. Difficult navigation in surrounding seas C. Weak rulers D. Lack of education

291. ## math

-x squared -2x +4 solve quadratic equation by factoring

292. ## chemistry

At standard temperature, a gas has a volume of 312 mL. The temperature is then increased to 115◦C, and the pressure is held constant. What is the new volume? Answer in units of mL

3√(x)ln(x)

294. ## physics

When two objects move uniformly toward each other, they get 3.0 m closer each second, and when they move uniformly in the same direction with their original speeds, they get 1.0 m closer each 17 seconds. What is the speed (in meters/second) of the faster

295. ## Play

In the play Piano Lesson, why does Berniece finally play the piano.

296. ## US HSITORY

HOW DID MEXICAN INDEPENDENCE CHANGE TEXAS

297. ## US HISTORY

WHAT PROBLEMS DID THE AMERICANS AND THE MEXICANS HAVE WITH EACH OTHER IN TEXAS

298. ## US HISTORY

WHAT HAPPENED AT THE CVITY OF GONZALES

299. ## Math - graphing

i am having trouble with a graphing calculator please help with these two questions 1. a census was taken from 2012 to 2020. the data collected is given in the following table. 2012-2020 L1 l2 0 6000 1 6300 2 6615 3 7012 4 7362 5 7878 6 8429 7 9272 8 10199

300. ## Physics

A 2.1 kg mass is connected to a spring with spring constant k= 180 N/m and unstretched length 16 cm. The pair are mounted on a frictionless air table, with the free end of the spring attached to a frictionless pivot. The mass is set into circular motion at

301. ## Lang. Arts

Which of the following groups of words in bold is nonrestrictive and should therefore be set off with commas in the sentence? A.My yarn which is blue and gray will make a very pretty scarf. B.Hats knitted by my mother are worn all winter by my family.

302. ## English

Revise the following paragraph, improving it without changing its overall meaning. Pay particular attention to sentence structure. Ever been assigned to work on a group project for class! Many students dread group projects: because one student typically