# Questions Asked onSeptember 28, 2012

1. ## Chemistry

You are asked to prepare 500. mL of a 0.150 M acetate buffer at pH 5.00 using only pure acetic acid, 3.00 M NaOH, and water. Calculate the quantities needed for each of the following steps in the buffer preparation. 1. Add acetic acid to ~400 mL of water

2. ## chemistry

is IBr a hydrogen bonding or dipole-dipole interactions or dispersion forces

3. ## Chem

Calculate the number of C atoms in 0.185 C6H14O.

4. ## Biology

Which of the following statements correctly compares the functions of a plant's roots and stem? The stem contains a high percentage of cells that provide structural support, unlike the roots. The stem is the first part of the plant to emerge from a seed,

5. ## physics

A loaded truck can accelerate at 3.2 m/s^2 It loses its load so that it is only 0.2 as massive. By what factor must the acceleration change for the same driving force?

6. ## Physics

A ball is thrown toward a cliff of height h with a speed of 27m/s and an angle of 60 degrees above horizontal. It lands on the edge of the cliff 3.0s later. What is the height of the cliff? What is the maximum height of the ball? What is the ball's impact

7. ## Calc 3

Find parametric equations for the tangent line to the curve of intersection of the paraboloid z = x^2 + y^2 and the ellipsoid 6x^2 + 5y^2 + 7z^2 = 39 at the point (−1, 1, 2)

8. ## College Chemistry

calculate the moles of sulfuric acid that remained in the solution after reaction with the carbonate. the tared mass of carbonate is 1.5179g

9. ## math

maurice puts 130 trading cards in protector sheets. He fills 7 sheets and puts the remaining 4 cards in an eighth sheet. Each of the filled sheets has the same number of cards. How many cards are in each filled sheet?

10. ## math

65 men 75 women are enfolled in calculus. There are 30 business majors, 40 biology majors, 50 computer science majors, and 20 mathematics majors. No person has a double. If a single calculus student is chosen, find the probability that that the student is

11. ## Economics

Which of the following firms caould raise prices and expect an increase in revenues? A)a firm product has an elasticity of 1 B)a firm whose product has an elasticity of 0.31 C)a firm whose product has an elasticity of 3.1 D)all firms regardless of the

12. ## 10th Grade Literary Essay

What does F. Scott Fitzgerald suggest about the state of the American Dream, the people who pursue it, and the impact of that pursuit through his depiction of Jay Gatsby and the people in Gatsby’s life? Include specific examples, quotations, and

13. ## CHEMISTRY

2C2H2+ 5O2-> 4CO2+ 2H20. If 1 mole of C2H2 reacts with oxygen, how many moles of C02 are produced.

14. ## math dividing fractions

Julia ate 1 over 2 pint of mint ice cream. Mark ate 3 over 4 of malt ice cream. How many times more ice cream did mark eat?

15. ## physics

A mass hangs on the end of a massless rope. The pendulum is held horizontal and released from rest. When the mass reaches the bottom of its path it is moving at a speed v = 2.3 m/s and the tension in the rope is T = 22.4 N. 1. What is the mass? 2. If the

16. ## Physical science.

A skydiver who jumps out of a plane that has a forward velocity of 40 m/s. That means that the skydiver has a forward velocity of 40m/s. Ignore the air resistance. The questions: What difference is there between the downward velocities of the skydiver who

17. ## chemistry

If the boron nitride molecule,BN, were to form, what would its structure look like? pls. need help

18. ## Physics

One kind of slingshot consists of a pocket that holds a pebble and is whirled on a circle of radius r. The pebble is released from the circle at the angle θ so that it will hit the target. The angle in the drawing is 35.5°. The distance to the target

19. ## Physics

An airplane whose air speed is 620km/h is supposed to fly in a straight path 35 degrees north of east. A steady 95km/h wind is blowing from the north. In what direction (angle) should the plane head?

20. ## Dynamics

The rotor is an amusement park ride where a person enters the Rotor when it is stationary and stands against the wall with their back against the wall. The rotor then begins to spin around a vertical axis. After reaching cruising speed, the floor drops

21. ## physics

Three charges are fixed to an xy coordinate system. A charge of +25C is on the y axis at y = +2.7 m. A charge of -16C is at the origin. Lastly, a charge of +66C is on the x axis at x = +2.7 m. Determine (a) the magnitude and (b) direction of the net

22. ## Physics

An arrow is shot at an angle of above the horizontal. The arrow hits a tree at an angle 45 degrees horizontal distance D = 220 away, at the same height above the ground as it was shot. Use g = 9.8 for the magnitude of the acceleration due to gravity. Find

23. ## chemistry

Determine the pH of a solution containing 0.045 M NaOH and 0.025 M KI: With activities: Without activities:

24. ## Science

On a winter day the temperature drops from –15°C to –25°C overnight. If a pan sitting outside contains 0.40 kg of ice, how much heat is removed from the ice for this temperature change?

25. ## physics

A mass m = 11.0 kg rests on a frictionless table and accelerated by a spring with spring constant k = 4979.0 N/m. The floor is frictionless except for a rough patch. For this rough path, the coefficient of friction is μk = 0.46. The mass leaves the spring

26. ## physics

A bicycle wheel of radius 0.4 m is spinning at a rate of 40 revolutions per minute. What is the centripetal acceleration of a point on the edge of the wheel? What is the period of the wheel's motion?

27. ## math

Each divisor was divided into another polynomial , resulting in the given quotient and remainder. Find the other polynomial the dividend Divisor: x+10,quotient,x^2-6x+10,remainder :-1 I am so confused help is appreciated

28. ## physics

A painter of mass 90.0 kg stands on a platform of mass 50.0 kg and pulls on two ropes which hang over pulleys, as shown. He pulls each rope with a force of 600.0 N. Assuming a coordinate system where +y is up, calculate the y-component of the acceleration

29. ## physics

.A 5.5kg riffle fires an 11gram bullet with a velocity of 1000m/s. a. find the velocity of a riffle? b. if the shooter holds the riffle firmly with his shoulder what will be the velocity assume the mass of shooter is 120kg?

30. ## psychology

Should the criminal justice system put as much emphasis as it does on eyewitness testimony? What are some possible circumstances that could influence eyewitnesses to say they saw something they might not really have seen?

31. ## physics

A mass m = 76.0 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius R = 19.7 m and finally a flat straight section at the same height as the center of the loop (19.7 m off the ground). Since the mass would not make it

32. ## math

Each dividend was divided by another polynomial, resulting in the given quotient and remainder. Find the divisor Divided:5x^3+x^2+3 ,quotient:5x^2-14x+42, remainder:-123

33. ## Chemistry Pretest

Fe can be prepared as 2 Al + Fe2O3 ----> 2 Fe + Al2O3. Suppose that 0.450 moles of Fe2O3 are reacted with an excess of Al. Suppose that 43.6 grams of Fe are obtained. What is the percent yield of Fe? a) 16.2% b) 60.7% c) 86.7% d) 43.4% Percent yield=

Which of the following is typically included in a stock listing? The company's SEC registration credentials The predicted price of the stock over the next year The number of shares of stock sold in a previous day The number of shares of stock sold in the

35. ## physics

A skier is pulled up a slope at a constant velocity by a tow bar. The slope is inclined at 22.2° with respect to the horizontal. The force applied to the skier by the tow bar is parallel to the slope. The skier's mass is 56.0 kg, and the coefficient of

36. ## 7th grade math standard form scientific notation

In standard form: 5. 3.2 x 10^3 7. 4.1 x 10^8 9. Write the average weight of a blue whale, 2.6 x 10^5, in standard form. 15. 2.5 x 10^-3 17. 1.05 x 10^-2 19. Write the size of a grain of very fine sand, about 9.35 x 10^-3 cm, in standard form. Can somebody

37. ## physics

A mass hangs on the end of a massless rope. The pendulum is held horizontal and released from rest. When the mass reaches the bottom of its path it is moving at a speed v = 2.3 m/s and the tension in the rope is T = 22.4 N. Now a peg is placed 4/5 of the

38. ## physics

The forces in the figure below are acting on a 2.1 kg object. Find the values of ax and ay, the x and y components of the acceleration. i.imgur. com/nNz9m. png this is one of the last problems on my homework that i just do not understand.. can someone

39. ## Math

The inclined ramp of the boat launch is 18 meters longer than the rise of the ramp. The run is 17 meters longer than the rise. How long are the three sides of the ramp?

40. ## physics

A horizontal rifle is fired at a bull's-eye. The muzzle speed of the bullet is 692 m/s. The barrel is pointed directly at the center of the bull's-eye, but the bullet strikes the target 0.0239 m below the center. What is the horizontal distance between the

41. ## math

The winner in a recent Los Angeles Marathon ran the 26-mile race in 2.23 hours. How many yards per minute did he run?

42. ## physics

Figure 18-23 shows three linear temperature scales, with the freezing and boiling points of water indicated.

43. ## Physics

On a playground slide, a child has potential energy that decreases by 1000 \rm J while her kinetic energy increases by 900 \rm J. What other form of energy is involved, and how much?

44. ## Math

Pool tables are rectangular, and their length is twice the width. Find the dimensions of a pool table if it occupies 162 ft2 of floor space

45. ## 7th grade math questions Scientific Notation

19. Write the size of a grain of very fine sand, about 9.35 x 10^-2 cm, in standard form. 31. The population of the US is expected to be 392 million people by 2050. Write this answer in scientific notation. 37. Write 10^29 - 10^28 in scientific notation.

46. ## Wine Chemistry

Is citric acid stronger than tartaric acid?

47. ## 7th grade science weather

1. Relative humidity is a measure of the amount of _______ that air is holding compared to the amount needed for saturation at a specific temperature. water vapor particles heat none of the above 2. Low, layered gray clouds that produce light precipitation

48. ## physics

A mass m = 76.0 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius R = 19.7 m and finally a flat straight section at the same height as the center of the loop (19.7 m off the ground). Since the mass would not make it

49. ## physics

an archer at the edge of a cliff fires an arrow from a height of 14.6 m above the ground at the bottom of the cliff. the arrow just clears a rock on a pillar that is 21.7 m above the gound which is 45.2 m horizontally away from the archer.determine a,the

50. ## Chemistry Pretest

Last and final question: Consider the reaction 2KNO3 + 10K ---> 6K2O + N2. If 155 grams of K reacted with 122 grams of KNO3, what is the limiting reagent? a) KNO3 b) K c) Neither d) not enough information I would think it's d? Because it doesn't ask to

51. ## physics

Im trying to study for my physics exam by doing some extra problems, however im stuck with this one. any help is much appreciated Two tiny spheres have the same mass and carry charges of the same magnitude. The mass of each sphere is 4.62 x 10-6 kg. The

52. ## English

In the first stanza the narrators bed is compared to a womb and a

53. ## Math

A catcher's and a pitcher's uniform numbers are consecutive integers whose product is 756. If the catcher's was the smaller number, determine the uniform number of each player.

54. ## Math HELPPPP

(a) Which of the following are examples of the expression "difference of two cubes"? (Select all that apply.) (y2 - 9)3 3 - 4y 64 - y3 (y - 1)3 y3 - 27 27 - 3y y3 (b) Which of the following are examples of the expression "cube of a difference"? (Select all

55. ## Pre-Calculus

Two sides of a triangle are x units and y units in length. The angle between them is theta. Prove that the area of the triangle is 1/2xysin(theta). I'm not sure how to do this question, I tried drawing a picture but I'm still not understanding it.

56. ## physics

an archer at the edge of a cliff fires an arrow from a height of 14.6 m above the ground at the bottom of the cliff. the arrow just clears a rock on a pillar that is 21.7 m above the gound which is 45.2 m horizontally away from the archer.determine a,the

57. ## Maths

How to do factorise ? What is Factorise ? Give me some examples ,please . Thank you !

58. ## Chemistry Pretest

1. What mass of the compound FeWO4 contains 50.0 grams of tungsten (atomic symbol W, atomic number= 74)? **Formula mass of FeWO4 is 303.69** a) 30.0 g FeWO4 b) 304 g FeWO4 c) 82.6 g FeWO4 d) 188 g FeWO4

59. ## Physics

An arrow is shot at an angle of above the horizontal. The arrow hits a tree at an angle 45 degrees horizontal distance D = 220 away, at the same height above the ground as it was shot. Use g = 9.8 for the magnitude of the acceleration due to gravity.

60. ## Physics

Two charges are placed on the x axis. One of the charges (q1 = +8.71C) is at x1 = +3.00 cm and the other (q2 = -28.6C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x =

61. ## 7th grade scientific notation help Ms. Sue

Write each number in scientific notation. 1. 4,800 2. 17, 200 3. 180,000 4. 343, 502 12. 0.00581 13. 0.00105 14. 0.0000078 15. 0.000027 16. 0.000000132 17. 0.000000009

62. ## science

it dorsn't give me a stage in the second stage, some animals just grow larger.Other change in___________

63. ## ICD9

All ICD9-Cm Codes must be supported by: A. Nonessential modifiers. B. physician documentation in the medical record. C. V codes. D. another diagnostic code.

64. ## Algebra

An investor invested a total of $2000 in two mutual funds. One fund earned 9% profit while the other earned a 6% profit. If the investor's total profit was$129, how much was invested in each mutual fund?

1. The ingredients, or building blocks, of an artwork (1 point) studies of art principles of art categories of art elements of art 2. The name of a color (1 point) value intensity hue fue 3. The arrangement of hues in a circular format (1 point) color

66. ## chemistry

N2+ 3H2 GIVES 2NH3 = -90.5 4NH3+5O2 GIVES 4NO+6H20 =-905.1 H2 +0.5 O2 GIVES H2O =-241.1 USE THESE VALUES TO DETERMINE ENTHALPHY CHANGES

Which shape does not have two pairs of parallel sides? A. rectangle B. square C. parallelogram D. trapezoid

68. ## Chemistry Pretest

11. How many moles of CO2 would be produced from 56 moles of O2 according to the following balanced equation? 2 C2H6 + 7 O2 ---> 4 CO2 = 6 H20 a) 16 b) 32 c) 224 d) 48 e) 8

69. ## physical science

explain why elements in a group on the periodic table have similar chemical properties?

70. ## Earth Science

Can someone five me an example of how carbon cycles through the Earth's system?

71. ## college physics

Two charges are placed on the x axis. One of the charges (q1 = +8.71C) is at x1 = +3.00 cm and the other (q2 = -28.6C) is at x2 = +9.00 cm. Find the net electric field (magnitude and direction given as a plus or minus sign) at (a) x = 0 cm and (b) x =

72. ## American Gov

2. Members of the Senate were originally chosen by the House of Representatives- True? 7. Which of the following does not serve to limit the power of the federal government? a. Tenth Amendment b. voting rights c. state legislators d. Bill of Rights C?

73. ## statistics

The average temperature in households is 67.6 degrees F. The standard deviation is 4.2 degrees F. A random sample of 51 households is to be selected What is the probability that the average of this sample will be within 1.4 STANDARD ERRORS of the

74. ## Math

The length of the luff is four times longer than the length of the foot of the sail. Find the length of the foot and the length of the luff.

75. ## Quantitative Chemical Analysis

assume an unknown sample to be 15% copper, weigh enough dried ore sample to use approximatele 35-45mL of .09M S2O3-. How many grams do I need to measure out to use 40.00mL of the thiosulfate solution?

1. Violent storms generally form along _____. (1 point) occluded fronts cold fronts warm fronts stationary fronts 2. Areas of low pressure usually have _____. (1 point) cloudy weather good weather descending air none of the above 5. Tornadoes can form when

77. ## social studies

Which one of the following U.S. mothers-to-be is least likely to receive prenatal care? A. Maria, a Puerto Rican teenager B. Gladys, an African American woman C. Ayiana, a Native American teenager D. Susan, a white woman I am saying A. But Im not sure

78. ## assessing development cognitive language observat

There are several strategies that can help preschool children Foster language production one strategy that involves asking questions after a child. speaks to encourage him or her to continue talking is called?

79. ## Psychology

If the concept is truck, the prototype might be: A. A ford pick up B. bulldozer C. An eighteen-wheeler D. Personnel carrier

80. ## Chemistry Pretest

Consider the following balanced equation. 2 H2 + O2 ---> 2 H2O Which of the following statements is false? a) One molecule of O2 will react with 2 molecules of H2 b) One mole of O2 will react with 2 moles of H2 c) The complete reaction of 32.0 g of O2 will

81. ## Math

Find the smallest positive integer d such that d=105m+216n, where m & n are integers.

82. ## Math

What multiplies together to make 300cm3 (volume)

83. ## Math

A standard basketball has a diameter of 9 9/16 inches (that is 9 inches and 9/16 of an inch). What sit he volume of air in the basketball?

84. ## grammar

He was arrested and, despite being in handcuffs, managed to escape from custody.

93. ## elementary school math

Which of the following symbols could you use to complete this number sentence? Explain your reasoning. .= + < # - > 7,000+800+9. 7,000+900+8

94. ## Chemistry

In industrial plants, what specific type of oil is used as heating medium?

95. ## College Chemistry

calculate the average volume of sodium hydroxide required for the titration of 25.00mL of the standard sulfuric acid solution. From my data i have trial 1 and 2 to be 19.80ml and 19.80ml of NaOH used so do i just add them and divide it by two to get the

96. ## math

what are the bars around the numbers in integer questions

97. ## Sociology/Psychology

I'm taking Sociology 1st semester and Psychology 2nd semester when I go to the 9th grade. I'm just curious but is there any topics (interesting ones) in Sociology and Psychology.

98. ## 7th grade language arts

Choose the demonstrative pronoun is the following sentence: "This invitation fell out of her backpack." her of backpack this

99. ## physics

The mass of the heavier block is 28 kg and the mass of the lighter blocks is 14 kg and the magnitude of the force of the connecting string on the smaller block is 24 N. Assume: g = 9.8 m/s^2 and the horizontal surface on which the objects slide is

100. ## Chemistry

How would I find the volume of 30% hydrogen peroxide solution from 20mL of 3% hydrogen peroxide solution?

101. ## science

machine fires 5 bullets per sec each of velocity 200m/sec. find power of the gun.

102. ## Precalculus

give an example of two decreasing functions whose product is increasing

103. ## Physics

A 2kg block is released from rest at position A and falls 12 meters to the floor. At position B, just before it lands, it is falling at 15m/s. a) if the blocks potential energy is zero at B, what is its potential energy at A?

104. ## ODU

FIND THE EXACT VALUE OF COS U 4/5, PI/2

105. ## understanding observation behavior

Which of the following method depends on heavily on the observers memory.

106. ## English

Should students be allowed to invade established neighborhoods and live in unlicensed and unsafe rooming houses? How can I re-write the above question so it is not biased?

107. ## 7th grade social studies

Explain the quote by Samuel de Champlain in your own words. "Through (exploration) we gain knowledge of different countries, regions and kingdoms; through it we attract and bring into our countries all kinds of riches; through it... Christianity (is

108. ## Math

Factor. y ^3 + 729

109. ## social studies

The number of multiple births (twins, triplets, etc.) has grown rapidly in the United States since 1980. The main reason for this increase is that: A. studies show that people are having more frequent intercourse. B. less frequent intercourse has resulted

110. ## Algebra 2

[(x^2+2x-15)/(x^2-4x-45)] / [(x^2+x-12)/(x^2-5x-36)]

111. ## arithmetic

If the average of a and b is 10 and a^2 - b^2 = 80, what is the value of b?

112. ## probl;em solving

in harry's attic there are three spider webs. the first web is twice as large as the second web. gthe third web is 3 inches larger than the first web. the combined width of the three webs is 1 foot and 6 inches. how long is each web?

113. ## assessing development cognitive language observat

When preschool child is first learning to print. alphabet letters he or she print letters upside down or backwards the teacher should.

114. ## trig

i have to draw a flat unit circle all the way to 4 pi in radians. i can get to 2 pi but i have trouble finding the radians if i went one more time around the unit circle.

115. ## Chemistry

a solution is 0.0300 m in Sodium. How many grams of sodium carbonate are necessary to prepare 900.0 ml of this solution? I don't know where to start on this.

116. ## Physics

a 150-N and 80-N force act upon an object. the angle between the two forces is 55 degrees. determine the magnitude and direction by trigonometric calculations.

117. ## Social studies

I have this poem I have to write it's about Walter prynne and the freedom of speech has to be ten lines and has to be rhyme scheme poem. I don't know how to do this. And my teacher said it's due and I don't get it and if I don't get it in I fail. Pls reply

118. ## Pre-Calculus

Two sides of a triangle are x units and y units in length. The angle between them is theta. Prove that the area of the triangle is 1/2xysin(theta). I'm not sure how to do this question, I tried drawing a picture but I'm still not understanding it.

119. ## math

twelve less than a number is 19. what is the number?

120. ## English III

how would you use the allusion "Manna" in a sentence?

121. ## maths

a hyperbola of eccentricity 3/2 has one focus at (1,-3). The corresponding directrix is the line "y". find an equation for the hyperbola?

122. ## english

a good thesis statement on why teachers should have the authority to remove disruptive students from their classes permanently.

123. ## math

How many grams of a drug are contained in 1L of a 30% solution?