# Questions Asked onOctober 4, 2007

1. ## ap chem

calculate the enthalpy of formationof solid MgOH2, given the following data: 2Mg(s) + O2(g)-> 2MgO(s) heat:-1203.6 Mg OH2(s) -> MgO(s) +H2O(l) heat: 37.1 2H2(g)+ O2(g) -> 2H2O(l) heat: -571.7 what equation would they want the three equations to develop

2. ## physics

A penny is dropped from the observation deck of the Empire State building (370 m above ground). With what velocity does it strike the ground? Ignore air resistance.

3. ## Statistics

A manufacturer makes two models of an item: model I, which accounts for 80% of unit sales, and model II, which accounts for 20% of unit sales. Because of defects, the manufacturer has to replace (or exchange) 10% of its model I and 18% of its model II. If

4. ## math

A stereo system is marked down from \$450 to \$382.50. What is the discount rate?

5. ## math

belinda used her calculator to find the decimal for the fraction 21/28.When she entered 21/28, the calculator gave an answer that looked familiar. Why do you think she recognized it?

6. ## Physics

A 40 kg crate is pulled across the ice with a rope. A force of 90 N is applied at an angle of 36 degreees with the horizontal. Neglecting friction, calculate: the acceleration of the crate; the upward force the ice exerts on the crate as it is pulled

7. ## physics

Glenda drops a coin from ear level down a wishing well. The coin falls a distance of 14.80 m before it strikes the water. If the speed of sound is 343 m/s, how long after Glenda releases the coin will she hear a splash?

8. ## language

Please help me in figuring out my worksheet that says to follow directions in the order they are given. 1.Write the word solar. 2.Add the 5th letter of the alphabet to the left of each consonant. 3.Add the 5th consonant of the alphabet to the right of the

9. ## Math

To travel 175 miles, it takes Sue, riding a moped, 4 hours less time than it takes Doreen to travel 66 miles riding a bicycle. Sue travels 19 miles per hour faster than Doreen. Find the times and rates of both girls.

10. ## history

need these letters unscrambled to make a nine letter word relating to native americans R E T A M I L A F The 4 letter is E the 5th letter is R and the 6th letter is I

11. ## Calculus

Find the derivative if y^3 + y = 2cosx

12. ## math

use mental math and the distributive property to simplify 25(-99)and 19x21

13. ## Physics

A golf ball released from a height of 1.80 m above a concrete floor, bounces back to a height of 1.06 m. If the ball is in contact with the floor for 4.62 ms, what is the magnitude of the average acceleration a of the ball while it is in contact with the

14. ## Physics

A piece of copper wire is formed into a single circular loop of radius 13 cm. A magnetic field is oriented parallel to the normal to the loop, and it increases from 0 to 0.70 T in a time of 0.45 s. The wire has a resistance per unit length of 3.3 10-2 /m.

15. ## Calculus

Find the derivative if x^3 + 4xy^2 - y^4 = 7

16. ## Math

Joe and Steve went to the store and Joe had seen this jacket that he had wanted.The jacket costed \$12.99 and all Joe had was \$10.99. Steve said he would give Joe the extra \$2dollars and 59 cent that he would have left out of buying his candy.Will Joe have

17. ## science

Why is it important to maintain core body temperature? and Why is it important to maintain the concentration of water within a mammals internal environment?

18. ## MATH

HOW MANY FOUR-LETTER CODE WORDS CAN BR FORMED USING A STANDARD 26-LETTER ALPHABET IF REPETITION IS ALLOWED IF REPETITION IS NOT ALLOWED

19. ## Physics

What force would you have to exert on a 324 N trunk up a 19 degree inclined plane so that it would slide down the plane with a constant velocity? What would be the direction of the force? The coefficient of friction between the plane and the trunk is .322.

20. ## Physical Science

Here's a question from my homework that I have no idea where to even beging with it. A European "weighs" 100 kg on Earth. a. What is his mass on Earth? b. What is his weight on Earth? c. What is his mass on the moon where the acceleration due to gravity is

21. ## Physics

-The brakes on your automobile are capable of creating acceleration of 19 ft/s2. If you are going 76 mi/hr and suddenly see a state trooper, what is the minimum time required to get your car to 55 mi/hr? For this answer, I got 1.62 s. -How far do you

22. ## ENGLISH

Is this sentence grammatically correct? I have had my ups and downs, my triumphs and my failures. It isn't a homework problem or anything; I am writing an autobiographical essay and I wasn't sure if this was correct or not... THANK YOU! :]

23. ## Chemistry

Do you know the carbon chain lengths for the different states of alkynes? Eg alkanes having a carbon chain length of 1-4 are gases, 5-16 are liquids and 17+ are solids. Are there similar rules for alkynes?

with the decimal that equals pi....(3.14....) until the 2 hundreth decimal place..how does the cumulative frequency column be used for a project like this one..???? the number is...(pi)

25. ## AP bio

Explain why adaptations of organisms to interspecific interactions do not necessarily represent coevolution. What would a researcher have to demonstrate about an interaction between two species to make a convincing case for coevolution? i don't understand

26. ## math

belinda used her calculator to find the decimal for the fraction 21/28. When she entered 21/28, the calculator gave her an answer that looked familiar. Why do you think she recognized it?

27. ## Psychology

What are the strengths and weaknesses of Naturalistic observation, Case studies, and Longitudinal Studies?

28. ## Physics

A golf ball released from a height of 1.80 m above a concrete floor, bounces back to a height of 1.06 m. If the ball is in contact with the floor for 4.62 ms, what is the magnitude of the average acceleration a of the ball while it is in contact with the

29. ## Chemistry

What is the maximum yield of NH3 that can be formed from 8.50 grams of N2 and 1.00 grams of H2 in the (balance) reaction N2 + 3H2---- 2NH3?

30. ## Math ... HELP!!!!!

What is the Least Common Multiple (LCM) of 78 and 104?

31. ## Algebra 2

1.) Write a system of equations that has NO solution. 2.) If you wanted to eliminate the y variables in the system of equations below, what would you multiply the first and second equations by?( Do not solve the equation) 2x-3y=8 7x-4y=11

32. ## history

in the eighteenth century liberals stressed? a)dictatorship b)equal of opportunity c)economic equality

33. ## mathrmatics

a basetball team has won 50 games of 75 played.the team still have 45 games to play.how many of the remaining games must the team win in order to win 60% of all the games during the season? a)20 b)22

34. ## math

Find the center (h,k) and radius r of the circle. (x-2)^2 + (y+3)^2 =16 a)(2,-3) r=16 b)(-3,2) r=4 c)(2,-3) r=4 d)(-3,2) r=16

35. ## math

suppose a new student starts school today and your teacher asks you to teach her how to find decimal equivalents for fractions. what would tou tell her? how would you convince her that your method works?

36. ## AP Chemistry

I know this is such an easy question, but I completely forgot how to do it. Can someone please help me out? Thanks. If 57.84 g of nickel (Cp = 0.0946 J/g Degrees C) originally at 97.4 degrees C is placed into a calorimeter with 48.24 g of water (Cp = 4.184

37. ## math

you visit your favorite depatment store and find that your have shirt is on special.the shirt normally cost \$60.00 and now has a 20% discount.how much will you sabe when you buy this shirt? a)\$22.00 b)\$32.00 c)\$12.00 d)16.00

38. ## History Part II

Was there really? Because the movies that I say for WW1 were basically untrained men dying by the minute in the war and their bodies were through in ditches or sometimes coffins. With over 15 million people dead in WW1 how would they keep track of

39. ## english

only when families are more articulate with identifying their needs and when builders and ploicy become more sensitive to human needs will the nation have a variety of good housing desinged,built,and seviced.if this sentnce was rewrote begginging with the

40. ## algebra

which of the following pairs of points both lie on the line whose equation is 3x-y=2? a)(2,-2) and (1,5) b)(2,4) and (1,5) c)(2,4) and (3,7) d)(3,7) and (3,-2)

41. ## Economics

Hi, Could you please help me with the following question? Bob and Jane decide to open their own business selling ergonomically correct office furniture that Jane has designed. Assume they operate this business from leased office space near their home. Also

42. ## math

I am having trouble with this motion problem.A jet travels 1,890 miles in 3 hours. flying against the same wind,the plane makes a return trip in 3 1/2 hours.Find the wind speed and the plane`s airspeed.My book gives the answer,but I just can not understand

43. ## economics

1. DETROIT -- Here's a million-dollar question: How does the global economy connect American car buyers and Russian bureaucrats? One person who can answer is Reg Modlin, an emissions specialist at DaimlerChrysler AG's U.S. unit. Mr. Modlin, like many other

44. ## physics

A Nile cruise ship takes 21.7 h to go upstream from Luxor to Aswan, a distance of 208 km, and 19.4 h to make the return trip downstream. Assuming the ship's speed relative to the water is the same in both cases, calculate the speed of the current in the

45. ## biology

Discuss how the concept of time applies to ecological situations and evolutionary changes. Do ecological time and evolutionary time ever correspond? If so, what are some examples? i don't get this question at all...please help thanks in advance

46. ## Defination

What's the word for a person who can think of things before they happen?

47. ## math

The ochestra at stripling middle school is responsible for cleaning a 15 mile highway. there are 45 students in the orchestra. If each member cleans and equal section, what decimal represents this section? A.0.3 B.0.33 C.o.3333... D.3.0

48. ## Economics

How can you obtain a downward sloping market demand curve from a horizontal firm demand curve experiencing perfect competition? If you sum up individual demand horizontally for the firm at the given market price will market demad not still be horizontal?

49. ## AP chemistry

If the percent hydration of CuCl2 x XH2O is 13% what is the coefficient of water?

50. ## History

What are some ways in which soilders in the USA Army communicated during the war with Hitler

51. ## Social Studies

How do I make a word web connecting two of my social studies vocabulary words?

52. ## sorry it's me but i need help in english.

Living in the U.S. now for almost nine years has made me adapt to the life and culture here. Despite the fact I still miss my family in India, I’m content with my life in America so far. I look forward to going to school every day, I love living in my

10+____=8+5

54. ## Math

The temperature changed from 11 degrees C at noon to -4 degrees C at 8:00 p.m. How many degrees did the temperature drop. Please illustrate answer. Thanks

55. ## MATH

HOW MANY DIFFERENT ARRANGEMENTS ARE THERE OF THE LETTERS IN TESTERS?

56. ## math

Find the general form of the equation of the circle. Center at the point (-4,-3); containing the point (-3,3) a) x^2+y^2+8x+6y-12=0 b) x^2+y^2+4x-6y+22=0 c) x^2+y^2-4x+6y+22=0 d) x^2+y^2+4x-6y+4=0

57. ## history

this collection of spells was buried with the mummy

58. ## Physics

Suppose you wish to make a solenoid whose self-inductance is 1.2 mH. The inductor is to have a cross-sectional area of 1.2 10-3 m2 and a length of 0.048 m. How many turns of wire are needed?

59. ## science

name of stars in caprcornius (seagoat)constellation

60. ## Chemistry

Is there an equation for acid rain? What is it?

61. ## CHEM

How would I go about answer this question? If 72.26 g of hot water at 83.6 degrees C is mixed with 43.86 g of cooler wayer at 38.4 degrees C what will be the final temp of the mixture? The Cp of liquid water is 4.184 J/ g degrees C

62. ## economics

suppose a firm's constant-returns to scale production function requires it to use capital and labor in a fixed ratio of two workers per machine to produce 10 units and that the rental rates for capital and labor are given by v=1, w=3. a. calculate the

63. ## History

Whats the word that means that someone is forced to participate in war.

64. ## american history

how do you translate eglish into modern english

65. ## History For bobpursley

You said that "line of duty" has a money value to it. Im using the phrase "line of duty" for a WW1 essay. Was there any money value involved then? And would it be the right to use "line of duty" in my essay if there was no money value involved for soliders

2 ---- 104 3 ---- 158 4 ---- 210 x ----? Write expression

67. ## Editing

On this hwk help forum, do you edit people's work? I have a paragraph and I need someone to look it over and make some corrections. Would anyone be willing to do that?

68. ## Math

If you have 78 and 104 what is the Least Common Multiples or (LCM)

69. ## science

what happens to the light in a microscope that causes the image to appear inverted

70. ## Math for Gina

Well I need the LCM for 78& 104 ok there

71. ## math

11/12-[1/3 1/4]=

72. ## per- calculus

Parrallel to the line 4x+3y=3; containing the points (6,0) a)3x-4y=-24 b)4x+3y=24 c)4x+3y=18 d)3x-4y=18 show all work

73. ## MATH

IF FOUR COINS ARE TOSSED, CONTRUCT A POSSIBILITY TREE TO DETERMINE IN HOW MANY WAYS ONR CAN OBTAIN TWO HEADS AND TWO TAILS

74. ## spanish

how did the europeans transform life in argentina and chile? and why was san martin considered a great liberator?

75. ## science

list one factor that affects salinity in the ocean temperatures? explain how each factor affects salinity or temperature.

76. ## Science

How are atoms held together?

77. ## math(geometry)

prove Given: line r is parallel to line s prove:

78. ## economics

in general the role of board of directors is to: a)direct the day to day activities of the film b)represent investor interest in management of the film c)insire that the film operates illegally d)provide staff assistance tothe ceo in stragetic matters

79. ## English

if anyone's heard of the experience machine, could they please tell me some pros about it?

80. ## science

what is the opposite of a stalactite

81. ## Health

We r learning about the reproductive organs and they seem to be confusing me on how they they function together to make an embryo.Can someone explain how they function?

82. ## math

a rectangle and triangle have equal areas.the lenght of the rectangle is 12 inches, and its width is 8 inches.if the base of the triangle is 32 inches,what is the length in inches drawn to the base? a)12 b)16 c)6 d)8 e)9

83. ## Literature

Can the following essay titled "Shooting an Elephant" by George Orwell (1903-1950) be a litterary cannon of today

84. ## Economics- Micro

You have an option to hire 2 hunters. The first hunter is able to kill two deers in an hour, the other hunter is able to kill one deer in an hour. Do you, without a doubt, hire the first hunter because he has an absolute advantage? My question is that as

85. ## Physics

Why does the central maximum of a diffraction pattern is twice as long as any other? Thank you

86. ## Comman Sense

There is this one term phrase when a solider dies while serving the counrty. Its something like. " in the line of duty." Im not quite sure what it is. Would you tell me the phrase.

87. ## english

what is a widow's walk? I am trying to explain this metaphor's meaning in the book, but I don't understand this term. Can any one help please???? THX A LOT!!!

88. ## Physics

Why does the central maximum of a diffraction pattern is twice as long as any other? Thank you

89. ## Ethnics

What are three characteristics of Orientalism.

90. ## Calculus

Find the derivative if y=sin^-1(3x)

91. ## Calculus

Find the derivative if y=sec^-1(x+3)

92. ## chemistry

how do u draw the lewis structure for something like CO -2 over 3. do u add 2 electrons on to the oxygen when yur finding the number of valence electrons cuz that's wat i thought u did but then i got all those questions wrong so wat do u do

-5x>15

94. ## math/science

What is the rate to fall safely? Ex. fall with a parachute from an airplane

95. ## Chemistry Conversions

How would you do this problem using fraction bars? The average diameter of a coronary artery is .43 cm. What is the diameter in nanometers?

96. ## history

my paper says the declaration accused the british king of"acts of pretended legislation." and then my paper says list four such acts of what he did.

97. ## letters,memo,and email messages

How would you approach creating a negative message for a superior.

98. ## french question

how does one say "the test will be difficult?"

99. ## science

tell what happens to each of the following as depth increases temperature pressure density

100. ## math

what is the slope of the line p[assing through points a (5,4) and b (0,3)? a)1/10 b)1/2 c)3/2 d)4/5 e)5

101. ## math

Find the center (h,k) and radius r of the circle. x^2 +y^2=4 a) (h,k) = (2,2); r=4 b) (h,k) = (0,0); r=4 c) (h,k) = (2,2); r=2 d) (h,k) = (0,0); r=16

102. ## chemistry

how many moles of x in 33.3g of substance?

m

104. ## math

1 kilometer= a)1,000centimeters b)1,000,000millimeters c)10 meters D)10,000centemeters e)100meters

105. ## science

one example of a chemical in food that is not a nutrient is? a)fiber b)selenium c)starch D)FOLATE

106. ## Algebra

Is this an example of the transitive property: G+G+G=D G^2=D

107. ## MATH

your high school diploma ffrom american academy landed you a job paying good money.you were wise and saved \$150,000 to buy the compmany.the nuts are listed at .01 pernut.you say you are wise and you are buying 3 millionnuts.the owner give you a

108. ## spanish

-how did the europeans transform life in argentina and chile? -what factors (music, literature, food, art, clothing and languages) contribute to create Argentina and Chileam cultures of today? How do they contribute to create it? -Why is San Martin

109. ## math

if the taxable income is 3,000..what is the federal income tax according to this chart, if income is over 0 but not over 23,350 the tax is 15percent of the amount over 0 besides the answer can you show me how you got the answer

110. ## grammar

in the sentence- There are many ways to cook eggs- what is the subject?

111. ## SPANISH

I REALLY NEED HELP WITH THIS: -how did the europeans transform life in argentina and chile? -what factors (music, literature, food, art, clothing and languages) contribute to create Argentina and Chileam cultures of today? How do they contribute to create

112. ## Defin.

There is this one thing that you always see in movies when a person puts a cloth on top of a person's mouth and the person is unconsious. What is on the cloth?

113. ## math

If h= 3 and k =4, then hk+4/2 -2=

4 ã4x =

115. ## Sociology

What exactly is "cultural purity?" I think I understand the concept, but I'm having a hard time putting it into words.

116. ## Calculus

(1 - x)^4 * (2x - 1)^5 its a derivative how can i solve this?

117. ## science

can anyone explain the cycle of malnutrition to me? i know the effects but not reall the cycle

118. ## math

if lauren and max were to measure their fish with decimals, would it be easy to tell which fish is longer?explain why or why not.

119. ## math

Squere root of 4x 4 power

120. ## math

Squere root of 4x 4 power =

121. ## hum130

Religion can affect people in many different ways. List at least two effects that organized religion has had on society and give examples from past and/or present world events that illustrate your examples.

122. ## anthropology

what can be an example of global apartheid? like something recent that has been going on...im kinda drawing a blank =[ thanks

123. ## Chemistry

I really don't understand this question. How do I work it out? Pure acetic acid, HC2H3O2 has the following characteristics: mp = 14.6 degrees C bp = 167.3 degrees C deltaHc = 274 j/g deltaHv = 1621 j/g Cp (s) = 1.72 J/g degrees C Cp (l) = 2.83 J/g degrees

124. ## math

If n=2 and x=1/2, then n(4-x)=

125. ## geometry

I keep forgetting, but I have a test tomorrow: what is a linear pair?

126. ## math

what is 83792 in expanded form using 10 powers.