# Questions Asked onMarch 23, 2012

1. ## chemistry

The rate constant for this first-order reaction is 0.320 s–1 at 400 °C. A--> Products How long (in seconds) would it take for the concentration of A to decrease from 0.830 M to 0.220 M?

2. ## physics!

Playing in the street, a child accidentally tosses a ball at 21 m/s toward the front of a car moving toward him at 18 m/s. What is the ball's speed after it rebounds elastically from the car?

3. ## Pre-Calc

A hot-air balloon is floating above a straight road. To estimate their height above the ground, the balloonists simultaneously measure the angle of depression to two consecutive mileposts on the road on the same side of the balloon. The angles of

4. ## physics

a hose pipe ejects water at a speed of 0.3m/s through a hole of area 50 cm*m.if the water strikes a wall normally, calculate the force on the wall , assuming the velocity of water normal to the wall is zero after striking?

5. ## Chemistry

At constant pressure, which of these systems do work on the surroundings? Check all that apply. A(s) + 2B(g) ---> C(g) 2A(g) + B(g) ---> 4C(g) A(g) + 2B(g) ---> 2C(g) A(s) + B(s) ---> C(g)

6. ## chemistry

The reaction described by this equation O3(g) + NO(g) -- O2(g) + NO2(g) has the following rate law at 310 K. rate of reaction = 3.0x10^6 M^-1 s^-1)[O3][NO] Given that [O3]=2.0× 10–4 M and [NO]=2.0× 10–5 M at t=0, calculate the rate of the reaction at

7. ## chemistry

The rate constant for this first-order reaction is 0.0570 s–1 at 400 °C. A-->Products After how many seconds will 14.0% of the reactant remain?

8. ## Types of BUsiness writing

Memorandum part. Draft an interoffice memorandum to Miriam Hopkins, the Director of Human Resources: A. Assume that you've received confirmation from Jeremy Dittmer for the date, time, and materials needed. The trainer he has assigned is Deb Walker

9. ## geometry

QUADRILATERAL ABCD IS A RECTRANGLE IF AC=2X+13 AND DB=4X-1 FIND DB

10. ## types of business writing

Draft an email of at least four complete sentences to Deb Walker the designated trainer: Confirm the arrangements for the seminar providing only the information she needs to arrive at the right place at the right time. Copy both to Mr, Dittmer and Ms.

11. ## Chemistry

Given acidity constant,Ka of benzoic acid is 6.28 X 10^-5. pH of 0.15 molar solution of this acid is ? Here is my method: Benzoic acid is a weak acid,hence it dissociates very little. So: C6H5COOH---> C6H5COO- + H+ [H+] and [C6H5COO-] are yet to be

12. ## precal

cotxsinx=cosx

13. ## statistics

What are the chances that a person who is murdered actually knew the murderer? About 64% of people who are murdered actually knew the murderer. Suppose that a detective file in New Orleans has 63 unsolved murders. What is the probability that A )at least

14. ## chemistry

a typical alberta home heated with natural gas assume methane CH4 (g) consuems 2.00ML of natural gas during the month of December. What volume of oxygen at SATP is required to burn 2.00ML of methane measured at 0 degrees and 120 kPa? the answer is 2.62ML

15. ## statistics

The data set given below has y^ = 3x - 5 for its regression equation. Find the standard error of estimate. x 3 2 5 8 y 4 1 10 19 A) 1.29 B) 0 C) 2.06 D) 0.17

16. ## physics

An experiment makes use of a water manometer attached to a flask. Initially the two columns in the gas manometer are at the same level and the air pressure in the flask and both sides of manometr is 1 atm. The experiment is set up when the air pressure is

17. ## Bob Pursley

I can not copy and paste to the board.

18. ## physics

A diver is jumping straight up with 2 m/s from a 15 meter platform. Calculate the maximum height of the diver, the diver’s velocity when reaches the water, and total time to reach the water.

19. ## language arts

Need some adverb help. In the sentence...The man looked extremely nervous. I know extremely is an adverb. Is nervous an adverb too? Thanks.

20. ## precal

sin^2x/cosx=sec^2x-1

21. ## chemistry

i need a molecular, ionic and net ionic equation for this : K_3 PO_4 + BaCl_2

22. ## chemistry

I really don't understand rate law. Could you explain that and help with this problem please? Determine the average rate of change of B from t=0 s to t=202 s. A-->2B Time (s) Concentration of A (M) 0 0.74 101 0.45 202 0.16

23. ## Calculus and vectors

A parallelogram is formed by R^3 by the vectors PA=(3,2,-3) and PB=(4,1,5). The point P=(0,2,3). a) what are the location of the vertices? b) what are the vectors representing the diagonals? c) what are the length of the diagonals?

24. ## chemistry

How much heat energy is given off when one kilogram of hydrogen gas at 25C and one atmosphere is combined with enough oxygen gas to make liquid water at 25C?

25. ## precal

csc^2x-cos^2xcsc^2x=1

26. ## Math

A company that produces a particular machine component has 3 factories, one each in Buffalo, Detroit, and Pittsburgh. 39% of the components produced come from the Buffalo factory, 36% of the components come from the Detroit factory, and 25% of the

27. ## physics

a construction worker accidentally knocks a brick from a building so that it falls in 4s to the ground.calculate a) the velocity of the brick as it hits the ground b)the distance fallen of the brick

28. ## chemistry

A fully sealed 50m^3 room at atmospheric pressure and temperature 20C contains two ballons, one containing helium and the other containing oxygen. The balloons each have a volume of 0.5m^3 and have gauge pressure 2m of water. The balloons are ruptured and

29. ## precal

cosx/sinxcotx=1

30. ## precal

secx/sinx-sinx/cosx=cotx

31. ## child psychology

Dean associates certain activities,roles,and traits as being typical for either males or females.His associtions conform to cultural stereotypes and encompass many gender-linked responses.This is an example of: A.roles B.Identity C.Atypicality I think its

32. ## Pre-Calc

Evaluate the expression without using a calculator(show work please)? (sin pi/4 cos pi/6 - sin pi/6 cos pi/4) the answer is 1/4(2-ã3)

33. ## physics

A mass M = 5 kg moves with an initial speed v = 3 on a level frictionless air track. The mass is initially a distance D = 0.250 m away from a spring with k = 844 N/m, which is mounted rigidly at one end of the air track. The mass compresses the spring a

34. ## statistics

The Denver Post stated that 80% of all new products introduced in grocery stores fail (are taken off the market) within 2 years. If a grocery chain introduces 66 new products, what is the probability that within 2 years , 7 or more fail? What is the

35. ## Calculus

Let R be the region bounded by the y-axis and the curves y = sin x and y = cos x. Answer the following. a)Find the exact area of R. b)A solid is generated by revolving R about the x-axis. Find the exact volume of the solid.

36. ## precal

sinx(ccscx-sinx=cos^x

37. ## physics

A 55.0 kg circus performer oscillates up and down at the end of a long elastic rope at a rate of once every 7.20 s. The elastic rope obeys Hooke's Law. By how much is the rope extended beyond its unloaded length when the performer hangs at rest?

38. ## Algebra

Use the substitution method to solve -x + 3y=24 5x +8y=-5

39. ## precal

sin^2x-1=sec^2x-tan^2x

40. ## Translation

Translate the point (5, 5) to the new origin given (h, k). Given center (h, k) = (- 3, - 3), find point (x', y'). Translate the point (- 8, - 8) to the new origin given (h,k). Given center (h,k) = (- 3, - 3), find point ( x', y').

41. ## math

A rectangular dog pen is to be sectioned off into two separate areas and made to enclose area of 225 feet. Find the dimensions of the pen that will require the least amount of fencing material.

42. ## Science

The bonds between ions of opposite charge is strongest when the ions are small, the lattice energy of LiF is more exothermic than the lattice energy of CsI. Explain.

43. ## fractions

sammi cuts a pizza into 8 equal parts she eats 2 pieces .what fraction of the pizza is left

44. ## ms.sue 3 grade english

CAUSE AND EFFECT A CAUSE TELLS WHY SOMETHING HAPPENED. AN EFFECT IS WHAT HAPPENED. WORDS SUCH AS BECAUSE AND SO ARE CLUES THAT SHOW CAUSE-AND-EFFECT RELATIONSHIPS. SOMETIMES,HOWEVER,CLUE WORDS ARE NOT USED. DIRECTIONS-READ THE STORY.THEN ANSWER THE

45. ## English

I have to write an english assignment about banning a reality tv show. One of the paragraphs has to be about how 1984 underpins the whole concept of the show. I chose (Next Top Model). I have found a lot of links like unacceptable standards of beauty,

46. ## World History

5. The success of the blizkrieg depended mainly on superiority in a. nuclear weapons b. naval power c. defense strategy d. mobile ground troops C? 10. It was difficult to write a peace treaty according to the Fourteen Points because the a. Germans wouldn't

47. ## Calculus and vectors

|C|=5 and |D|=8. The angle formed by vectors C and D is 35 degrees, and the angle formed by vectors A and C is 40 degrees. Determine |B|. Could someone explain this question

48. ## Physics

A child pushes a merry go-round from rest to a final angular speed of 0.6 rev/s with constant angular acceleration. In doing so, the child pushes the merry-go-round 1.8 revolutions. What is the angular acceleration of the merry go-round? rad/s^2 This is

49. ## English

Can anyone explain this following quote: "Freedom is a right to one's dignity as a man" --Archibald MacLeish

Find the power input of a force F=(7 N)ˆý + (3 N) ˆk acting on a particle that moves with a velocity v = (6 m/s)ˆý. Answer in units of W

Find the power of a force F= (10 N)ˆý +(−4 N)ˆj if the velocity v = (−4 m/s)ˆý +(4 m/s)ˆj. Answer in units of W (^i and ^j means i hat and j hat)

52. ## art

how did portrait painting change from the 1500s to the 1600s

53. ## maths

the circle is given by the equation x^2+y^2+8x-7/2y=0 find (i)coordinates of the centre and the radius (ii)coordinates of the point where the circle crossesthe x-axis

54. ## College Physic

2) A car traveling with 5 m/s encounters a deer. The drivers slams on the breaks, the breaks lock. The car skids to a complete stop on the road ahead (and the deer runs away). Why does the car stop (where does all the kinetic energy it had go)? Find the

55. ## Calculus

If a(0,-1,3)+b(1,1,1)-c(1,2,5)=(-2,3,-8), determine a,b,c

56. ## Math

Suppose that you select 2 cards without replacement from an ordinary deck of playing cards. a) If the first card that you select is a heart, what is the probability that the second card that you select is an heart? b) If the first card that you select is

57. ## Chemistry

A solution of household bleach contains 5.25% sodium hypochlorite, NaOCl, by mass. Assuming that the density of bleach is the same as water, calculate the volume of household bleach that should be diluted with water to make 500.0 mL of a pH = 10.23

58. ## Math

The weights of adult long-tongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will: a) weigh at most 15 grams? b) weigh less than 30

59. ## Chemistry

When solving Hess law problems,do we need to use all the equations given to get the Htotal or just choose the relevant equations that are related to the final equation required? Let's say there r 5 equations given,but the relevant equations are 3 only ,so

60. ## pre-algebra

how long will it take to earn \$568.75 in interest if \$2500 is invested at a 6.5% annual interest rate

61. ## Math

A mall has three department stores, J C Penney, Macy’s, and Sears. A survey of 1863 people exiting the mall found that 279 made a purchase at J C Penney, 240 made a purchase at Macy’s, 364 made a purchase at Sears, 76 made a purchase at J C Penney and

62. ## maths

solve for x given that (1/8)^12x =2^x+3

63. ## Chemistry

How long can we use a bottle containing anti-bumping granules? Can it be used indefinitely?

64. ## math

two records and three tapes cost \$31.three records and two tapes cost \$29 .find the cost of each record and each tape

65. ## English

I urgently need you to revise this paragraph I need to prepare on Gulliver's travels. Thank you 1) Gulliver’s Travels, which can be regarded as Swift’s masterpiece, consists of four books, each dealing with the various adventures of the ship’s

66. ## Chemistry

Write the mole ratio for Al+3 ion and CO3-2 ion in this equation, 2Al(NO3)3 + 3Na2CO3 = Al2(CO3)3 + 6NaNO3

67. ## physics!

A 64 kg skater, at rest on frictionless ice, tosses a 12 kg snowball with velocity by v = 53i+ 14.0j m/s, where the x- and y- axes are in the horizontal plane. Find x-component v(x) of the subsequent velocity of the skater. As well as Find y-component v(y)

68. ## physics!

Wildlife biologists fire 22g rubber bullets to stop a rhinoceros charging at 0.84 m/s. The bullets strike the rhino and drop vertically to the ground. The biologists' gun fires 15 bullets each second, at 72 m/s, and it takes 36 s to stop the rhino. What

69. ## English

I left out these sentences. Thank you very much. I really need your revision. Thank you very much. 1) His last voyage leads him to the island inhabited by the Houyhnhnms, horses endowed with reason that rule over the ....., a vile and filthy species of

70. ## Math

in a group of 30 students,20 are male,15 are from southern region,9 from the central and 6 from the north.if the proportion of female students is the same for each region,how many students are either female or from the central{or both}A.9 B.10 C14 D.16

71. ## Chemistry

Solid ammonium nitrate can decompose to dinitrogen oxide gas and liquid water. What is delta G at 298K?

72. ## math

Let f(x) = ax^3 + bx^2 + 3x – 4. If f(x) is divided by (x – 2), the remainder is 2. When it is divided by (x – 1), the remainder is -2. Find a and b.

73. ## physics

A triathlete swims 1200 m due to east followed by 1500 m due northeast (45o). What is the overall displacement? (magnitude and angle). Calculate the displacement with long-hand calculations.

74. ## math

When px^3 – 2px^2 + 3x – p is divided by (x – 1), the remainder is -5. Find p.

75. ## Thesis example

Pregnancy women with alcohol dependency are at high risk of their unborn child being born with obstetric that can causes mental retardation, facial deformity, and other neurological problems.

76. ## English

please show me an example of an in text citation from an article

77. ## AP CHEMISTRY

The Kb for ammonia (NH3) at 25°C is 1.8* 10-5. By using the value of Kb, calculate ΔG° for the equilibrium

78. ## Chem

Calculate the final temperature when a 16.2 gram sample of ice at 0oC is placed into a styrofoam cup containing 128 grams of water at 79.0 oC. Assume that there is no loss or gain of heat from the surroundings. Heat of fusion of ice = 333 Jg-1 Specific

79. ## maths

prove that tan^2 (x/2)=1-cosx/1+cosx

80. ## Res/341

what are some ways to reduce bias in focus groups or any data collection method?

81. ## physics

an object accelerates uniformly along a straight line from a velocity of 10ms-1 until 25ms-1 in 5s. a)the velocity of the object during the first 10s of motion b)the time taken to reach a final velocity 50ms-1

82. ## visual

What is the diffrent kind of lines in art

x+y>1

84. ## Math

If f(x)=x^5+2x+1, then (f^-1)'(4)=?

85. ## 12th Grade Life Orientation

in 10-15 lines critically discuss five ways in which the human or environmental impact causes within any community in South Africa.

86. ## precal

sec^2x+tan^2xsec^2x=sec^4x

measurdment

88. ## geometry

A tent is shaped like a pyramid. It has a square base measuring 8 feet on a side and a height of 6 feet. What is the volume of the tent?

89. ## precal

cosx/secx+sinx/cscx=sec^2x-tan^2x

90. ## precal

sec^4x-tan^4x=1+2tan^2x

91. ## English

I forgot to include this sentence. Thank you. If you want, you can help me write a short description of your school including the summer courses and the students' mobility opportunities.

92. ## precal

sinx/1-cosx+1-cosx/sinx=2cscx

93. ## English

Can you please help check the sentence again. I forgot to include the verb. If you want, you can help me write a short description of your school including the summer courses and the students' mobility opportunities your school offers.

94. ## biology

1. what is the function of the menstrual cycle? 2. Trace the path of a sperm from the male body? 3. Examine the two small lungs found on either side of the heart? Describe their size and function?

95. ## algebra

If you need 3 pounds of fertilizer for 100 square feet of soil, how much do you need for 4 sq.ft.; 6 sq.ft.; 8 sq.ft.?

96. ## Statistics

team members estimated that a group of participants spent an average of \$90.00 with a standard deviation of \$15.00. What is the maximum amount that you can spend and still be in the lowest 20%? and the minimum that you need to be in the highest 15%?

97. ## child psychology

which young adult is long-term identitity foreclosure or diffusion A. college graduate who switches majors B.An aspiring chef who has no opportunity for culinary training. C.A young woman with several possible vocational choices. D.A peace corps volunteer.

98. ## BioChem

Write the chemical equation for the reaction that occurs when you add NaOH solution to NaH2PO4/Na2HPO4 buffer solution

99. ## physics

A certain uniform spring has spring constant k. Now the spring is cut in half. What is the relationship between k and the spring constant k' of each resulting smaller spring? (Use the following as necessary: k)

100. ## physics

A 7000-kg freight car rolls along rails with negligible friction. The car is brought to rest by a combination of two coiled springs as illustrated in the figure below. Both springs are described by Hooke's law and have spring constants with k1 = 1700 N/m

101. ## English

Writeacher, can you please check these sentences? Thank you very much. 1) My list included 27 students, including an older student from class IV F who would like to be involved in a science project to be carried out in English. 2) As you can see 17 of your

102. ## Types of Business writing

BUSINESS LETTER ASSIGNMENT Assigment: write a business letter according to the background. Background:Assume that you’ve worked for the last five years as an administrative assistant for the Human Resources Department of Broadworth General Hospital. The

103. ## math

what is the number pattern 17-23-?-18-20-25-21-9-15-16?

104. ## English

In some the sections in collection 6, setting plays an important role in shaping the writers idea of what home is,using a chart below, briefly describe the setting of three sections, and tell how the three writers feel about their homes, include at least

105. ## physics

A child loses his balloon, which rises slowly into the sky. If the balloon is 13 cm in diameter when the child loses it, what is its diameter at the following altitudes? Assume that the balloon is very flexible and so surface tension can be neglected. (a)

106. ## Chemistry

500.0mL of 0.220 mol/L HCl(aq) was added to a high quality insulated calorimeter containing 500.0mL of 0.200mol/L NaOH(aq).Both solutions had a density of 1.000g/mL & a specific heat of 4.184 J/g.K. The calorimeter had a heat capacity of 850.0 J/degree C.

107. ## Physics-11

A 12 kg object is at the top of a 41 degree inclined ramp. It is released and it reaches the bottom of the 85 m ramp in 2.3 seconds. what is the force of friction between the object and the ramp? What is the coefficient of friction? Can someone help me do

108. ## World History

5. The success of the blizkrieg depended mainly on superiority in a. nuclear weapons b. naval power c. defense strategy d. mobile ground troops C? 10. It was difficult to write a peace treaty according to the Fourteen Points because the a. Germans wouldn't

109. ## economics

Young Saul, a budding mctaemhtiaian and printer, is making himself a fake ID. He needs it to say heâ€™s 21. The problem is heâ€™s not using a computer, but rather he has some symbols heâ€™s bought from the store, and thatâ€™s it. He has

110. ## math

3x-5y=24 3x+5y=6

111. ## Math

How would I write 150,783 in words? Is it one hundred fifty thousand seven hundred and eighty three???

112. ## calculus

If the sun rises at 6 AM and is directly overhead at 12 noon, estimate the time (hour and minutes) when a 34-foot tree will have a 24-foot shadow.

113. ## Math

If f(x)= {-5x+5x^2 -1

114. ## statistics

A fast food chain claims that all of its quick win soda cups are winners. (There is a little tab you pull off the side of the cup which says either you are a winner or not. Lisa bought 8 sodas to try her luck. What is the probability that at least 5cups

115. ## statistics

At a small college it is known from previous years that 35% of all college freshman start in college algebra. The new freshman class has 100 students in it, What is the probability that between 35 and 42 freshman will start in college algebra? Is it

116. ## conics

given A(6,8) and B(-6,-8) write an equation in terms of x and y for all points P(x,y) such that segment PA is perpendicular to segment PB. simplify the equation and interpret your answer.

117. ## Calculus Grade 12 University

The cost, in dollars, for the production of x felt-tipped pens is C(x) = 48 000 + 0.28x + 0.00001x^2, and the revenue is R(x) = 0.68x - 0.00001x^2. What production level maximizes profit?

118. ## Calculus Grade 12 University

Use the second derivative test to find the local minimum and maximum values of each function, wherever possible. A) f(x) = 16/x + x^2 B) s(t) = t^4 - 8t^3

119. ## chemistry

i need a molecular equation, ionic and net ionic equation for this : K_3 PO_4 + 〖Ca(NO〗_3 )_2

120. ## Calculus Grade 12 University

Determine the critical numbers and find the absolute maximum and minimum values of the function y = 8x^3 + x^4 for x e [-8,2]

121. ## Math

Find the maximum value of f(x)=5x^(2/3)-x^(5/3) on [1,4]. thank you!

122. ## pol science

Locate indiana state’s constitution and examine the major elements and articles of the constitution. Review its contents and functions. Search for information about the judicial, educational, and social service systems offered in indiana state and the

123. ## chemistry 111

Write an account of your daily life routine that would include measurements in metric units only.

124. ## Chemistry

Suppose you want to heat a mug of water (250mL) from room temperature at 25oC to 100oC to make a cup of tea. How much energy (in units of calories and joules) would you need from your microwave? Please make chart!!

125. ## Geography

Can someone check these for me? 1.What problem has been at the heart of the intense political struggles in Central America? Unequal distribution of usable land is the heart of the political struggle. There is a shortage of farmland in order to meet the

126. ## physics

A vibration platform oscillates up and down with an amplitude of 8.8 cm at a controlled variable frequency. Suppose a small rock of unknown mass is placed on the platform. At what frequency will the rock just begin to leave the surface so that it starts to

127. ## Social Studies- Rome and Christianity

How did the acceptance of Christianity change life in the Roman empire?

128. ## physics

A 59.1 kg ice skater, moving at 13.3 m/s, crashes into a stationary skater of equal mass. After the collision, the two skaters move as a unit at 6.65 m/s. Suppose the average force a skater experience without breaking a bone is 4656 N. If the impact time

129. ## statistics

Let U, V be random numbers chosen independently from the interval [0; 1] with uniform distribution. Find the cumulative distribution and density of each of the variables (a) Y = U + V. (b) Y = Absolute value of (U - V).

130. ## physics

A 59.1 kg ice skater, moving at 13.3 m/s, crashes into a stationary skater of equal mass. After the collision, the two skaters move as a unit at 6.65 m/s. Suppose the average force a skater experience without breaking a bone is 4656 N. If the impact time

131. ## Math

How do you find the surface area of Prisms and cylinders? The stuff in my math workbook does not help me like at all! Please Help!

132. ## math percentiges

If the shoes cost 80.00 and i can get 30% off how would i set that problem up?

133. ## chem

calculate the pH of 0.25 M formic acid and 0.40 M sodium formate

134. ## chem pH

calculate the pH when 10 mL of .511 M sodium acetate and 20.00 mL of 0.350 M acetic acid

135. ## statics

Suppose we want to estimate the average number of purchases in a given hour in a local convenience store. Using this example, describe in your own words how you would go about determining this average through: a. Drawing a random sample b. Drawing a

136. ## RUBY MS

what is 8.3% of 132,000,000

137. ## Chemistry

How many mL of 3.0 M HCL are required to neutralize 250 mL of 2.0 M MgCL2 ?

138. ## Chemistry

How many grams of water are formed when 250 mL of 2.0 M Mg(OH)2 are neutralized by a solution of HCL ?

139. ## World History

Are these in correct chronological order? 1- Annexation of Austria 2- Nazi-Soviet Pact 3- Surrender of France 4- Attack on Pearl Harbor 5- Dropping of Atomic Bomb on Hiroshima Thanks -MC

140. ## World History

I need help putting these in chronological order: Munich agreement Attack on Poland Invasion of the Soviet Union Recapture of the Philippines by Allies Invasion of Italy Thanks -MC

Thesis statment : The physiology of alcohol dependence causes physiological aspects of the obstetric and the effect of alcohol during pregnancy can cause mental retardation, facial deformity, and other neurological problems.

142. ## Algebra 2

(2x^3-x^2-48x+15)/(x-5) Divide and find the quotient and remainder?

143. ## math

each set of probabilities is associated with a rolling cube. What numbers are marked on the faces of each cube? P(2)=1/3 P(4)=1/3 P(6)=1/3

144. ## English

Can you please check these sentences and tell me which one are possible? Thank you. 1) He didn't let on the secret to anyone. He didn't let out the secret to anyone. 2) He didn't let on that he knew Mary's secret. He didn't let out that he knew Mary's