# boB

Popular questions and responses by boB
1. ## Economics

A monopoly firm faces a demand curve given by the following equation: P = $500 − 10Q, where Q equals quantity sold per day. Its marginal cost curve is MC =$100 per day. Assume that the firm faces no fixed cost. You may wish to arrive at the answers

2. ## Chemistry

Assuming that sea water is a 3.5 wt % solution of NaCl in water, calculate its osmotic pressure at 20°C. The density of a 3.5% NaCl solution at 20°C is 1.023 g/mL.

3. ## Pre Calculus

Find all $2 \times 2$ matrices $\bold{A}$ that have the property that for any $2 \times 2$ matrix $\bold{B}$, $\bold{A} \bold{B} = \bold{B} \bold{A}.$

4. ## Chemistry

Balance the following equation for a half reaction that occurs in basic solution. Use e– as the symbol for an electron. SO3^2- ---> S2O4^2-

5. ## Microecon help

Please help! Review for a test and am so lost! (1) An article in the New York Times (Oct. 18, 1990) described a successful marketing campaign by the French champagne industry. The article also noted that “many executives felt giddy about the

6. ## LCM of two numbers?

lcm of two numbers pi/3 pi/2 How do I do it? Would it be pi or pi/6? Thanks

7. ## math

I look at a random time of day at a digital clock (that shows times from 1:00 through 12:59). What is the probability that (ignoring the colon) I see a palindrome such as 8:08? Express your answer as a common fraction.

8. ## Math

Of 30 students, 12 play football, 17 play soccer, and 5 play both, how many play neither?

50. ## geometry

What is the most precise name for quadrilateral ABCD with vertices A(–3, 2), B(–1, 4), C(4, 4), and D(2, 2)? 1. parallelogram 2. rhombus 3. quadrilateral 4. rectangle

51. ## physics

two objects are thrown from the top edge of a cliff with a speed of 10 m/s. one object is thrown straight down and the other straight up. if the first object hits the ground in 4.0 second, the second hits the ground in ________ seconds after the first

52. ## chemistry

Calculate the number of carbon atoms in 0.75 L of acetone (CH3COCH3). (density = 1.3 g/mL and boiling point = 48.5 degrees Celsius)

53. ## math

Why couldn't the two elephants go swimming together?

54. ## Chemistry

The following equation represents the decomposition of a generic diatomic element in its standard state. (1/2)X2(g)--->X(g) Assume that the standard molar Gibbs energy of formation of X(g) is 5.45 kJ·mol–1 at 2000. K and –64.30 kJ·mol–1 at 3000. K.

55. ## Physics

A woman on a bridge 75.0m high sees a raft floating at a constant speed on the river below. She drops a stone from rest in an attempt to hit the raft. The stone is released when the raft has 7.00m more to travel before passing under the bridge. The stone

56. ## Physics

When a wheel is rotated through an angle of 35 degrees, a point on the circumference travels through an arc length of 2.5 m. When the wheel is rotated through angles of 35 rad and 35 rev, the same point travels through arc lengths of 143 m and 9.0 X 10^2

57. ## math

What set of reflections and rotations would carry rectangle ABCD onto itself? Rectangle formed by ordered pairs A at negative 4, 1, B at negative 4, 2, C at negative 1, 2, D at negative 1, 1.

58. ## Data

Bridget works part time in a shoe store. Sometimes when it is not busy, she rearranges the shoes for fun. If she takes six different pairs of shoes and rearranges them in a row, in how many ways can she rearrange them so that no two shoes match? Is the

59. ## physics

A plastic rod is rubbed against a wool shirt, thereby acquiring a charge of −4.9 µC. How many electrons are transferred from the wool shirt to the plastic rod? The elemental charge is 1.6 × 10−19 C.

60. ## Physics

Work of 730 J is done by stirring an insulated beaker containing 80 g of water. What is the change in the temperature of the water? Please show calculation

61. ## Chemistry

A 0.1300 g iron ore sample was dissolved in hydrochloric acid and the iron was obtained as Fe2+(aq). The iron solution was titrated with Ce4+ solution according to the balanced chemical reaction shown below. After calculation, it was found that 0.0259 g of

62. ## Math

Terry bought some gum and some candy. The number of packs of chewing gum was one more than the number of mints. The number of mints was three times the number of chocolate bars. If gum cost 6 cents a pack, mints cost 3 cents each, and chocolate bars cost

63. ## Chemistry

A chemist performs a series of reactions that produce binary lithium compounds. The elements include sulfur, chlorine, nitrogen, fluorine, selenium, oxygen, and iodine. The models below represent the ionic radii of compounds formed by reacting lithium with

64. ## Geography

The acceptance of bribes by government officials who manage natural resources is an example of... A.profit maximization. B.productivity. C.environmental regulations. D.corruption. i chose A because that was in the book and it was false

65. ## math

1. Which of the following numbers is a rational? A. 4/5 B. square root of 27 C. 4.02002000200002... D. Square root of 31 2. Which type of number is shown below? 0.313311333111... A. repeating decimal B. rational C. irrational D. terminating decimal 3.

66. ## trig

An airplane is flying in the direction 148° with an airspeed of u = 920 kilometers per hour. Because of the wind, its groundspeed and direction are v = 820 kilometers per hour and 140°, respectively (see figure). Find the direction and speed of the wind.

67. ## Chemistry Buffers

Write reactions showing how each of the following buffers would neutralize added HCl. HF and NaF Express your answer as a balanced chemical equation. Identify all of the phases in your answer. HC2H3O2 and KC2H3O2 Express your answer as a balanced chemical

68. ## physics

Net force F causes mass m1 to accelerate at rate a. A net force of 3F causes mass m2 to accelerate at rate 2a. What is the ratio of mass m1 to mass m2?

69. ## Math

Webster Aquatic Center offers various levels of swimming lessons year-round. The March 2005 Monday and Wednesday evening lessons included instructions from Water Babies through Adults. The number in each classification is given in the table that follows.

70. ## Physics

A 1200-kg frictionless roller coaster starts from rest at a height of 24 m. What is its kinetic energy when it goes over a spot that is 12 m high?

71. ## Economics

Suppose that some firms in a competitive industry are earning zero economic profits, while others are experiencing losses. All else equal, in the long run, we would expect the number of firms in the industry to A. increase. B. decrease. C. remain the same.

72. ## Auditing

1. Which of the following matters would an auditor most likely consider to be a significant deficiency to be communicated to the audit committee? A. Management's failure to renegotiate unfavorable long-term purchase commitments. B. Recurring operating

73. ## Chemistry

Use the dilution relationship (Mi x Vi = Mf x Vf) to calculate the volume of 0.500 M NaOH needed to prepare 500 mL of .250 M NaOH. This is my work ? L Solution = 500mL x (1L/1000mL) = .500L ? mol NaOH = .500 L Solution x (0.250 M NaOH/1 L Solution) = .125

74. ## algebra

what is the value of 11x^-3y^-1 for x = -1 and y = 2?

75. ## physics

A force acts on a 2kg mass and gives it an acceleration of 3 m/s^2. what acceleration is produced by the same force when acting on a mass of (1) 1kg? (2) 4kg? (3) how large is the force?

76. ## Pre Calculus

For a vector $\bold{v}$, let $\bold{r}$ be the reflection of $\bold{v}$ over the line $\bold{x} = t \begin{pmatrix} 2 \\ -1 \end{pmatrix}.$ [asy] unitsize(1 cm); pair O, V, R; O = (0,0); V = (3,1); R = reflect(O,(2,-1))*(V); xaxis(-2,4); yaxis(-3,1);

77. ## Science

In a chemical compound, would you expect an oxide ion to be joined with one atom of calcium or one atom of potassium? Why?

78. ## Math

In first gear, or low gear, an automobile's engine runs about three times as fast as the drive shaft. In second gear, the engine does not have to run as fast; usually it runs about 1.6 times faster than the drive shaft. Finally, in third, or high gear, the

79. ## English II

On a proud round cloud in a white high night. A. alliteration B. consonance C. assonance D. limerick

80. ## Math

A cattle train left Miami and traveled toward New York. 14 hours later a diesel train left traveling at 45km/h in and effort to catch up to the cattle train. After traveling for four hours the diesel train finally caught up. What was the cattle train's

81. ## Physics B

A car slows down from 23 m/s to rest in a distance of 85m. What is its constant acceleration? I got -6.224, but a friend was telling me it's -3.11 and that I had to divide by 2. Why is that?

82. ## Math

Scott Mason purchased a 5-unit apartment building as an investment before he retired. From the rent he collects each month, Scott pays out $1,025 for expenses. How much rent must he charge for each of the 5 apartments if he wants to make$450 profit each

83. ## statistics

The distribution of B.A. degrees conferred by a local college is listed below, by major. Major Frequency English 2073 Mathematics 2164 Chemistry 318 Physics 856 Liberal Arts 1358 Business 1676 Engineering 868 9313 What is the probability that a randomly

84. ## Math

A fence 12ft high runs parallel to a tall building at a distance of 2ft from the building. What is the length of the shortest ladder that will reach from the ground over the fence to the wall of the building?

85. ## algebra

Find an equation of the line that satisfies the given conditions. Through (5, 3) and (4, 7)

86. ## Trigonometry

The wheels of a scooter have a diameter of 4.5 inches. If the person riding the scooter is traveling down hill at 15.0 mph. what is the approximate angular speed of the wheels in radians per second

87. ## english

Identify the italicized word according to its class in structural linguistics. (There) are no easy answers.

88. ## chemistry

Consider the following reaction: CaCN2 + 3H2O ¨ CaCO3 + 2NH3 105.0 g CaCN2 and 78.0 g H2O are reacted. Assuming 100% efficiency, which reactant is in excess and how much is leftover? The molar mass of CaCN2 is 80.11 g/mol. The molar mass of CaCO3 is

89. ## chemistry

express liquid pentanol and gaseous oxygen as a chemical reaction

90. ## math

Farmer Brown had some animals. One-fourth were horses, one-half were cows, and the rest were pigs. He had 8 pigs. How many animals did he have altogether? I know you would get a common denominator for 1/4 and 1/2 which would be 4 so you would have 1/4+2/4=

91. ## Algebra II

Maria and Zoe are taking Biology 105 but are in different classes. Maria's class has an average of 78% with a standard deviation of 5% on the midterm, whereas Zoe's class has an average of 83% with a standard deviation of 12%. Assume that scores in both

92. ## Math, Geometry and Physics

An enemy ship is on the east side of a mountainous island. The enemy ship can maneuver to within 2500 meters of the 1800 meter high mountain peak and can shoot projectiles with an initial speed of 250m/sec. If western shoreline is horizontally 300 meters

93. ## Physics

The density of copper is 8.96 g cm^−3 and its molar mass is 64 g mol^−1. Calculate the mass of 1 atom of copper.

94. ## Statistics

50 employees in an office wear eyeglasses. 43 have single-vision correction, and 7 wear bifocals. If two employees are selected at random from this group, what is the probability that both of them wear bifocals? What is the probability that both have

95. ## Chemistry

Green plants use light from the sun to drive photo synthesis. Photosynthesis is a chemical reaction in which water (H2O) and carbon Dioxide (CO2) chemically react to form the simple sugar glucose (C6H12O6) and oxygen gas (O2). What Mass of oxygen gas is

96. ## chemistry

What is the mass of sodium needed to make 2 g of sodium oxide (4Na + O2 → 2Na2O)? Ar values: O = 16, Na = 23. please help I'm really struggling. also please try to explain it to the simplest form because I really don't understand.

97. ## physics

A 1000 kg car traveling is at 40.0 m/ s. To avoid hitting a second car the driver slams on his brakes. The brakes provide a constant friction force of 8000 N. ( a) Find the minimum distance that the brakes should be applied in order to avoid a collision

98. ## Pre Calculus

Let $\bold{w} = \begin{pmatrix} 2 \\ -1 \end{pmatrix}$. There exists a $2 \times 2$ matrix $\bold{P}$ such that $\text{proj}_{\bold{w}} \bold{v} = \bold{P} \bold{v}$ for all 2-dimensional vectors $\bold{v}$. Find $\bold{P}$.