# Sara

Popular questions and responses by Sara
1. ## statistics

the probability that a house in an urban area will develop a leak is 5%. if 23 houses are randomly selected, what is the probability that none of the houses will develop a leak?

2. ## math

Two cars are side by side. One is 3.9 meters long. The other is 6% shorter. How long is the second car? I know the answer is 3.7, but how?

3. ## math

Find dy/dx and d2y/dx2. x = et, y = te−t

4. ## Chemistry

The compound M2X3 has a molar solubility of 0.0190 M. What is the value of Ksp for M2X3? Here are the choices: 1. 3.52 × 10^-6 2. 4.12 × 10^-5 3. 8.91 × 10^-8 4. 2.48 × 10^-9 5. 2.67 × 10^-7

5. ## chemistry

When the conductivity is at a minimum, what must be true about the amount of Ba(OH)2 compared to H2SO4? The Ba(OH)2 dissociates as Ba+2 + 2 OH-. H2SO4 dissociates as 2 H+ + SO4-2. Why does it not conduct at this low point? Why does it conduct more before

6. ## math

When 300 apple trees are planted per acre, the annual yield is 1.6 bushels of apples per tree. For every 10 additional apple trees planted, the yield reduces by 0.01 bushel per ten trees. How many apple trees should be planted to maximize the annual yield?

Jen purchased a condo in Naples Florida for \$699,000. She put 20% down and financed the rest at 5% for 35years. What are Jens total finance charge?

8. ## Geometry

30. PLis the angle bisector of KPM.Which can you conclude from this statement? You also can see this question number 30 on this website.Please add hyperlink. micahshue.weebly.com/uploads/2/2/5/6/22568286/final_exam_review.pdf How answer is A and i want

9. ## Chemistry

Calculate the molarity and the molality of an NH3 solution made up of 30 g of NH3 in 70 g of water. The density of the solution is 0.982 g/ml. Molar Mass of NH3 = 17.04 g

10. ## Geometry

Based on the information in the diagram, can you prove that the figure is a parallelogram? Explain. a. Yes; opposite sides are congruent. b. Yes; opposite angles are congruent. c. No; you cannot prove that the quadrilateral is a parallelogram. d. Yes; two

11. ## Geometry

YZ = √ 5 and XZ = √ 2. Find XY. Answer in simplified radical form. It's a right triangle, Y vertex is 90 degree. plz help.

12. ## English

Read the passage. Zeke and Petra went to the horse show over the weekend, they said they saw Arabians and other breeds performing in the show ring. Which answer correctly explains what is incorrect about the passage? A. A comma splice is used to connect

13. ## math (solid mensuration)

A light is placed 5 ft. from the center of a globe 3 ft. in diameter. Find the area of the illuminated portion. thank you!

14. ## math

I am A number in the Last row on the hundreds chart. my ones digit is even.the differance between the ones digit and tens digit is 5.What number am i?

15. ## Geometry

YZ = √ 5 and XZ = √ 2. Find XY. Answer in simplified radical form. in the given triangle picture Y vertex is 90 degree. plz help.

16. ## linear algebra

Let T be the plane 2x−3y = −2. Find the shortest distance d from the point P0=(−1, −2, 1) to T, and the point Q in T that is closest to P0. Use the square root symbol '√' where needed to give an exact value for your answer. I need help with this

17. ## chemistry

Based upon the intermolecular forces present, rank the following substances according to the expected boiling point for the substance: MgF2, H2O, HCl, N2

18. ## Geometry

The diagonals of an isosceles trapezoid divided it into one pair of congruent triangles and one pair of similar triangles.

19. ## Mendelian Genetics

Assume you are performing a cross between a plant that is heterozygous for the dominant traits red flowers and wrinkled seeds, with a plant that is homozygous for the recessive traits white flowers and smooth seeds. Assume the alleles are R for red

20. ## How many milliliters of a stock solution of 6.00 M

How many milliliters of a stock solution of 6.00 M HNO3 would you have to use to prepare 0.190 L of 0.490 M HNO3? I used the equation M1V1=M2V2 6M*V1 = 0.190L*0.490 M lead me to this V1=0.190L*0.490M/6.00 M =0.0931 L per M/6.00M =0.0155166L

21. ## science

You know that a collision must be "elastic" if: The momentum of the two-object system doesn't change The sum of the final kinetic energies equals the sum of the initial kinetic energies There is no change in the internal energies of the objects (thermal

22. ## math

The value of Sara's new car decreases at a rate of 8% each year. 1.Write an exponential function to model the decrease in the car's value each month. 2.Write an exponential function to model the decrease in the car's value each week. 3.Write an exponential

23. ## Chemistry

From the equation below, how many grams of barium sulfate can be produced from 20.8 g of barium chloride? BaCl2 + Na2SO4 -> BaSO4 + 2NaCl

24. ## U.S. History

which of the following was not a weakness of the articles of confederation (1781-1789)? A) a week "league of friendship" among the states B) the requirement of unanimous approval by all 13 states for amendments C) no judicial branch D) no congressional

25. ## Chemistry

Given the thermodynamic data in the table below, calculate the equilibrium constant for the reaction: 2SO2(g)+O2--> 2SO3 Substance (DeltaH^o) (Delat S^o) SO2 -297 249 O2 0 205 SO3 -395 256 Answer (it was given) 2.32x10^24 Even though the answer is given

26. ## math

How many gram ofsodiun fluoride should be added to 100000liter of drinking water containing 0.6 ppm of sodium fluoride to provide a recommended concentration of 1.75 ppm

27. ## DrBobb222 : Chemistry HElp...Please Check

Standardization of the Sodium Thiosulfate Solution Make up a standard solution of potassium iodate by accurately “weighing by difference” about 0.1 g of KIO3 and placing it in your 100 mL volumetric flask. Fill the flask to mark with distilled water.

28. ## Chemistry

Elemental sulfur can be converted to sulfur dioxide by combustion in air. Sulfur dioxide will react with water to form sulfurous acid (see balanced equation below). SO2(g) + H2O(l) → H2SO3(l) What mass of sulfur dioxide is needed to prepare 29.36 g of

29. ## math

The formula of a trapezoid is A=1/2h(b1+b2) Express b1 in terms of A,h,and b2 I did A=1/2hb1+1/2hb2 A=hb1/2 +hb2/2 A-hb2(2/h)=hb1/2(2/h) A-b2=b1 I am not sure if this is correct? I was confused on how to do this. Any help or explanation is greatly

30. ## chemistry 30a

What volume (in mL) of an 8% w/v acetic acid solution would be needed to form 2.2 L of carbon dioxide gas at 25.2 degrees Celsius and 0.9982 atm? Assume the acid is reacted with excess sodium bicarbonate, and round your final answer to two sig figs.

31. ## Science

Which of the following is a characteristic of nonmetals? Nonmetals are often brittle solids. Nonmetals are often malleable. Nonmetals often conduct electricity. Nonmetals are often ductile.

he value of a new car depreciates at a rate of 12% per year. Write an equation to represent the approximate value of a car purchased for \$23 000. Determine the value of the car two years after it is purchased. Approximately how many years will it take

33. ## Math

Jason was hired to mow a lawn that covers an area of 2 3/4 acres it took him 4 1/8 hours to complete the job what was his unit rate and hours per acre you multiply the numerator and a complex fraction by the reciprocal of the denominator to calculate our

Andres Michael bought a new boat. He took out a loan for \$23,980 at 3.75% interest for 4 years. He made a \$4,470 partial payment at 4 months and another partial payment of \$3,180 at 9 months. How much is due at maturity?

35. ## Physics

Multiple Concept Example 9 provides background pertinent to this problem. The magnitudes of the four displacement vectors shown in the drawing are A = 16.0 m, B = 12.0 m, C = 13.0 m, and D = 23.0 m. Determine the (a) magnitude and (b) direction for the

36. ## finance

Assume that the export price of a Nissan XTerra from Osaka, Japan is ¥3,750,000. The exchange rate is ¥121.84/\$. The forecast rate of inflation in the United States is 2.8% per year and is 0.6% in Japan. a. What is the export price of the XTerra at the

37. ## chem

How many moles of O are in 13.0 mol Fe(NO3)3? can you please find this using dymensional analysis and show me how you worked it? Thans

38. ## Socials

How did Napoleon help to spread feelings of nationalism throughout Europe? Explain why you think nationalism is a positive or negative force, or both. Napoleon helped to spread feelings of nationalism throughout Europe by initially using it to help him

39. ## chemistry

Using your answer from Part A, calculate the volume of a mole of Na atoms (in cm3/mol ). Assume that the entire volume is occupied by Na atoms leaving no gaps or holes between adjacent atoms. (Answer A is V= 2.70*10^7)

40. ## Maths

A boy spends 1/4 of his money on sweets and 1/3 on computer games. What fraction of his money does he not spend?

41. ## Chemistry

CoCl2CO+Cl2 Keq=7.6*10^-4 M CoCl2 is introduced in a closed container until its concentration is .890 M. What will be the concentration of Cl2 once the reaction has reached equilibrium?

42. ## Calculus

Calculate the height of a cylinder of maximum volume that can be cut from a cone of height 20 cm and base radius 80 cm , please help me

43. ## science

how does a magnitude-8.0 earthquake could be classified as a low-intensity earthquake? LAST SCIENCE QUESTION!

44. ## math

The height of a frustum of a pyramid is 12 and the areas of its bases are 9 and 25. What is the volume of the frustum?

45. ## Math

Marie forgot the formula for finding the area of a circle, so she divided the circle into sectors and created a parallelogram-shaped figure. What should she use as the height of the figure? A.the radius B.360 C.12 of the circumference D.the circumference

46. ## Math

Form the perfect square trinomial in the process of completing the square. What is the value of c? x^2 + 3x + c = 7/4 + c c =

47. ## chemestry

consider the reaction 2N2O(g) == O2(g)+2N2(g).which of the following will cause a shift in the equilibrium to the left?

48. ## Chemistry

The complex [Co(ox)3]4- has a high-spin electron configuration. How many unpaired electrons are there in the complex? I know because it's a high-spin, it's tetrahydral shaped. But I don't know what (ox) is so, I'm stuck in finding the oxidation state of Co

49. ## Chemistry

Calculate how much acetylene (C2H2) can be produced from 358 g of H20 and an excess of CaC2 if the perfect yield for this reaction is 94.5% CaC2+H2)-> C2H2+C2H2+CA(OH)2

50. ## Chemistry

Dinitrogen pentoxide, N2O5, decomposes by first-order kinetics with a rate constant of 0.15 s-1 at 353 K. (a) What is the half-life (in seconds) for the decomposition of N2O5 at 353 K? (b) If [N2O5]0 = 0.0579 mol·L-1, what will be the concentration of

51. ## Calculus - HELP plz!

Find all of the first partial derivatives of f(x,y,z)=arctan y/xz

52. ## Chemistry

How much of NaOH (in grams) is needed to prepare 546 mL of solution with a pH of 10.00 ?

53. ## chem

Which of the following elements would you expect to gain electrons in chemical changes? (Select all that apply.) gold chromium zirconium nitrogen iodine

54. ## MACROECONOMICS

Which of the problems in the construction of the CPI might be illustrated by each of the following situations? Explain. a. the invention of the Sony Walkman b. the introduction of air bags in cars c. increased personal computer purchases in response to a

55. ## Algebra

The lesser of two consecutive even integers is 10 more than one-half the greater. Find the integers.

56. ## statistics

The professor teaching a large introductory class gives a final exam that has alternate forms, A, B, and C. A student taking the exam using Form B is upset because she claims that Form B is much harder than Forms A and C. Discuss how percentile point data

57. ## Physics

A flywheel turns through 60 rev as it slows from an angular speed of 2.8 rad/s to a stop. How much time is required for it to complete the first 30 of the 60 revolutions?

58. ## Chemistry

Sulfur dioxide reacts with chlorine to produce thionyl chloride and dichlorine oxide S: 32.0 amu O: 16.0 amu Cl: 35.45 amu SO2 + 2Cl2 --> SOCl2 + Cl2O If 0.400 moles of chlorine gas reacts excess sulfur dioxide, how many moles of dichlorine oxide are

59. ## science

A car of mass 2900 kg collides with a truck of mass 4800 kg, and just after the collision the car and truck slide along, stuck together. The car's velocity just before the collision was < 34, 0, 0 > m/s, and the truck's velocity just before the collision

60. ## econ

The terms below are measures or individual components of the money supply. Specifically considering the money supply of the United States, rank these items from largest to smallest in terms of dollar value. Currency, M2,M1,Balances in savings accounts,

61. ## Chemistry

A sample of oxygen is collected over water at 22 C and 762 torr. What is the partial pressure of the dry oxygen? The vapor pressure of water at 22C is 19.8 torr.

62. ## Statistics

Solve the following problems by using the binomial formula. a. If n = 4 and p = .10 , find P(x = 3) . b. If n = 7 and p = .80 , find P(x = 4) . c. If n = 10 and p = .60 , find P(x ¡Ý 7) . d. If n = 12 and p = .45 , find P(5 ¡Ü x ¡Ü 7) .

63. ## chemistry

In the reaction between CV+ and –OH, one species is acting as the Lewis base, the other as the Lewis acid. (Note: A Lewis acid is not necessarily a proton donor. It is, however, always an electron pair acceptor). Which reagent is the Lewis acid? A. CV+

64. ## math

A regular triangular pyramid has slant height 6 cm and base edges of length 15 cm. Find the volume of the pyramid and the surface area.

65. ## Science

When hair is combed with a hard rubber comb, the hair becomes positively charged because the comb A. Transfers protons to the hair B. Remove electrons from the hair C. Transfers electrons to the hair D. Remove both times from the hair I could be removed

66. ## Chemistry

Which of the following elements is least likely to form a cation that will then form an ionic bond with an ion of a Group 7A element? S K Rb Fr

Andres Michael bought a new boat. He took out a loan for \$23,980 at 3.75% interest for 4 years. He made a \$4,470 partial payment at 4 months and another partial payment of \$3,180 at 9 months. How much is due at maturity?

68. ## Empires

I need help to compare and contrast the Babylonian and Hittite empires

69. ## CALCULUS-plz help!

For the curve r = 2 sin 3(theta): Find the arc length of one petal

70. ## Social Studies

The 1978 Supreme Court decision in Bakke v. Regents of the University of California A. ruled in favor of affirmative action within specified limits. B. established the "red state-blue state" divide. C. established the rights of students to appeal college

71. ## Math

A science museum requires 3 adult chaperones for every 15 students on a field trip. How many chaperones would be needed for a group of 125 students?

72. ## Chemistry

A solution of 2.50 g of a compound having the empirical formula C6H5P in 25.0 g of benzene(C6H6) is observed to freeze at 4.3 degrees C. Calculate the molar mass of the solute and its molecular formula.

73. ## Math

Mary buys 8 widgets for \$40.00. She adds \$1.00 in enhancements to each widget and sells them for \$9.00 each. What is Mary's estimated gross profit margin? 25% 33% 39% 44% 50% 67\$

74. ## Physics

A car is traveling along a straight road at a velocity of +31.0 m/s when its engine cuts out. For the next ten seconds, the car slows down further, and its average acceleration is a1. For the next five seconds, the car slows down further, and its average

75. ## math

Find how many six-digit numbers can be formed from the digits 2, 3, 4, 5, 6 and 7 (with repetitions), if: the numbers formed must be divisible by 25

76. ## Chemistry

Restart the PhET simulation and set it up in the following manner: select Oscillate, select No End, and use the parameters in parentheses by sliding the bars for Amplitude (1.00 cm), Frequency (1.20 Hz ), Damping (none), and tension (highest). Using the

Which best describes Hitler's beliefs as expressed in Mein Kampf? Revolution was needed to create a classless society. Germany could control the world with the help of the Japanese. All races could live peacefully under German domination. Jewish people

78. ## History

what are two themes that would be appropriate for thematic time lines of important events from prehistory to A.D.1600.

79. ## calculus

A street light is mounted at the top of a 6-meter-tall pole. A man 2 m tall walks away from the pole with a speed of 1.4 m/s along a straight path. How fast is the tip of his shadow moving when he is 16 m from the pole?

80. ## math

what is the largest negative coterminal angle of -417?

Imagine that you have a 6.00 L gas tank and a 3.00 L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 115 atm, to what

82. ## physics

A car travels on a straight road for 40km at 30km/h. It then continues in same direction for 40km at 60km/h. a)What is the average velocity of the car during the 80km trip?(assume it moves in positive x direction) b)What is the average speed? c)graph and

83. ## chemistry

For the following reaction at equilibrium in a closed vessel, ΔrH = −153 kJ per mol of CH3CHO. CH3CHO(g) ⇌ CH4(g) + CO(g) Which of the following statements are correct? a. For the thermodynamic equilibrium constant, K at 298 K is greater than K at 500

84. ## math

A sphere of radius 3 is inscribed in a cylinder. What is the volume inside the cylinder but not inside the sphere?

85. ## math

A regular square pyramid has a height of 2 and lateral edges of length 10. What is the lateral area and total surface area of the pyramid?

86. ## Physics

I need help with this question with explanation. Thanks A particle of mass m starts from rest at position x = 0 and time t = 0. It moves along the positive x-axis under the influence of a single force Fx = bt, where b is a constant. The velocity v of the

87. ## english 3

huck mentions that he wishes the widow douglas could know about his efforts to save the men on the wreck of the walter scott. pretend that you are huck and write a letter to the widow, explaining the situation and what you did about it. try to copy the

88. ## physics

If 335 g of water at 65.5 °C loses 9750 J of heat, what is the final temperature of the water? Liquid water has a specific heat of 4.18 J/(g.°C). °C (Answer a number only, no units. Round to the tenth place). This is an example of an endothermic or

89. ## algebra

Bob needs to wash the windows on his house. He has a 25-foot ladder and places the base of the ladder 10 feet from the wall on the house. How far up the wall will the ladder reach?

90. ## Chemistry

In which of the following substances does sharing of electrons between two atoms occur? He Nal PO43– Ag

91. ## Chemistry

When the following reaction took place at 23.8 and a pressure of 758 torr, 3.9 L of o2 were collected. What mass of KCIO3 decomposed? KCIO3->KCI+O2

92. ## physics

Calculate the magnitude of the gravitational force between the Earth and an m = 6.00 kg mass on the surface of the Earth. The distance to the center of the Earth from the surface is 6.37×103 km and the mass of the Earth is 5.98×1024 kg. B)Calculate the

93. ## chemistry help!!

The half-life for the process 238U 206Pb is 4.5 109 yr. A mineral sample contains 45.9 mg of 238U and 16.8 mg of 206Pb. What is the age of the mineral? i used the equation: n(T)=n(O)/2^(t/halflife) and i got 6.53e9 but it is wrong. what am i doing wrong?

94. ## MATH

You wish to mentally estimate the total cost of items that have the following prices: \$1.85, \$.98, \$3.49, \$9.78, and \$6.18. Rounding off the items to the nearest half-dollar, your estimate of the total cost of these items is A. \$22.50. B. \$22.30. C.

95. ## Math

What words have a horizontal line of symmetry when printed horizontally, and a vertical line of symmetry when printed vertically. The only word I have is HI.

96. ## calc

If 4x2+3x+xy=2 and y(2)=–10 , find y'(2) by implicit differentiation. i keep getting the wrong answer for this problem evn when plugging 2 in for y.

97. ## chem

A 1.0 M solution of an unknown weak base has a pH of 12.3 at 25 oC. What is the identity of the base? a. Ammonia, pKb = 4.8 b. Aniline, pKb = 9.5 c. Methylamine, pKb = 3.4 d. Pyridine, pKb = 8.8

98. ## Math

When a class took a math test, 15% of the class failed, 25% made some mistakes (but didn’t fail), and 24 students got perfect scores. How many students were in the class?