# Questions Asked onJanuary 24, 2013

1. ## Chemistry

2. Suppose that the amount of algae in a pond doubles every 4 hours. If the pond initially contains 90 pounds of algae, how much algae will be in the pond after 12 hours? A.)720 pounds B.)360 pounds C.)1,440 pounds D.)114 pounds I think the answer is D.

2. ## math

how do owners of large estates spend their time.

3. ## Math

Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line. y = 8 sin x, y = 8 cos x, 0 ≤ x ≤ π/4; about y = −1

4. ## algabre

the speed of the current in a river is 6 mph a ferry operator who works that part of the river is looking to buy a new boat for his business everyday his route takes him 22.5 miles against the current and back to his deck and he needs this trip in a total

A compound contains 38.7% K, 13.9% N, and 47.4% O by mass. What is the empirical formula of the compound?

6. ## Chemistry

The neutralization of H3PO4 with KOH is exothermic. H3PO4(aq) + 3KOH(aq) -> 3H2O(l) +K3PO4(aq) +173.2KJ 70.0 mL of 0.207 M H3PO4 is mixed with 70.0 mL of 0.620 M KOH initially at 21.87 °C. Predict the final temperature of the solution if its density is

7. ## Chemistry

For melting point determination, what is the optimum rate of heating near the melting point? What are the problems, if the rate of heating is too slow or fast?

8. ## Physics

Identical point charges of +2.1 ìC are fixed to diagonally opposite corners of a square. A third charge is then fixed at the center of the square, such that it causes the potentials at the empty corners to change signs without changing magnitudes. Find

9. ## Physics

How much work is needed to stop a 20g bullet moving with a speed of 150ms-1

10. ## physics

Two racing boats set out from the same dock and speed away at the same constant speed of 102 km/h for half an hour (0.500 h), the blue boat headed 26.1° south of west, and the green boat headed 38.8° south of west. During this half-hour (a) how much

11. ## Chemistry

Hydroxylapatite, Ca10(PO4)6(OH)2, has a solubility constant of Ksp = 2.34 × 10-59, and dissociates according to Ca10(PO4)6(OH)2(s) --> 10Ca2+(aq) + 6PO43-(aq) + 2OH-(aq) Solid hydroxylapatite is dissolved in water to form a saturated solution. What is the

12. ## Math

5. Suppose that the volumes of four stars in the Milky Way are 2.7 × 1018 km3, 6.9 × 1012 km3, 2.2 × 1012 km3, and 4.9 × 1021 km3. What is the order of the stars from least to greatest volume? A.) 2.7 × 1018 km3, 6.9 × 1012 km3, 4.9 × 1021 km3, 2.2

13. ## Math

Adam drew two same size rectangles and divided them into the same number of eqal parts. He shaded 1/3 of one rectangle and 1/4 of the other rectangle. What is the least number of parts into which both rectangles could be divided?

14. ## phy

An electric kettle contains 1.5 kg of water at 100o C and powered by a 2.0 kW electric element. If the thermostat of the kettle fails to operate, approximately how long will it take for the kettle boil dry? (Take the specific latent heat of vaporization of

15. ## Differential Equations

The velocity v of a freefalling skydiver is well modeled by the differential equation m*dv/dt=mg-kv^2 where m is the mass of the skydiver, g is the gravitational constant, and k is the drag coefficient determined by the position of the driver during the

16. ## algebra

Chase scored 14 points on Monday, and he doubled his score each day thereafter. How many points did he score on Thursday? A. 224 points B. 112 points C. 56 points D. 42 points Thanks :)

58. ## Math

Find the decibel intensity level at a rock concert if the intensity was measured at 3.98x10^-3

59. ## chemistry

if the relative atomic mass of natural copper is 63.54,calculate the proportions of the isotope 65cu and 63cu

60. ## English

Read the clauses. Then write main or subordinate for each clause. if the clause is a subordinate clause add a main clause to make it a complex sentence Before I go to school Subordinate Before I go to school I take a shower We heard a concert at Town Lake

69. ## Math

After 14 boys leave the concert, the ratio of boys to girls is 3 to 10. If there are p girls at the concert, write an algebraic expression for the number of boys at the beginning of the concert in terms of p

70. ## chemisrty

how many grams of cai2 are present in 3.28 moles? Can someone explaine how to do this question as well?

71. ## Physics

You hang mass m=0.22 kg on a spring with constant 12 N/m. You pull the mass down a distance of 0.04 m from its equilibrium position and release it. You measure the period to be 0.85 s. If you instead pull the mass down 0.12 m from its equilibrium position

72. ## Physics

Light is incident from water onto a flat transparent slab of material, at an angle of 48.8° with the normal. The reflected ray and the refracted ray are perpendicular to each other. What is the index of refraction of the transparent substance?

73. ## Physics 1

A ball starts from rest and rolls down a hill with uniform acceleration, traveling 150 m during the second 5.0 s of its motion. How far did it roll during the first 5.0 s of motion?

74. ## Physics

A pendulum clock is accurate on earth, where the period of its pendulum is 1.00 s. (a) Find its period on the moon, where gravitational acceleration is 1.6 m/s2. (b) During a 2 h interval, what would be the elapsed time shown on the clock? CAN YOU PLEASE

75. ## Physics

A plane is flying southwest at 155 mi/h and encounters a wind from the west at 45.0 mi/h. What is the plane's velocity in respect to the ground in standard position? I know the answer, but can't figure out how to get the answer. Any help would be

76. ## math

Jenna is going to paint one wall of her bedroom gray. She needs a gallon of paint. A gallon costs $17.00 and one quart of paint costs$4.39. Which is the better buy?

77. ## math

angle ABC and DEF are supplementary angles. the measure of DEF is 20 degrees less than 3 times the amount of ABC. what are ABC and DEF.

78. ## math

Seigi and Gavin both worked hard over the summer. Together, they earned a total of $425. Gavin earned$25 more than Seigi. Hoe much did each of them earn??

79. ## Math

Rusty is building a doghouse for his dog, Wheezer. He is making the dimensions of the doghouse proportional to his own house, which has a length of 54 feet and a width of 36 feet. If wheezer's new home is going to have a length of 6 feet, what will be the

80. ## chem

a simple hwk question.. i don't understand what i need to do.. 1-butanol (shown below) burns in the presence of oxygen to give off carbon dioxide and water by the following reaction: C4H9OH + 6 O2 ==> 4 CO2 + 5 H2O If 40.88 mL of 1-butanol burns

81. ## chem hwk

a simple hwk question.. i don't understand what i need to do.. 1-butanol (shown below) burns in the presence of oxygen to give off carbon dioxide and water by the following reaction: C4H9OH + 6 O2 ==> 4 CO2 + 5 H2O If 40.88 mL of 1-butanol burns

82. ## math

The ratio of mystery books to the number of science fiction books is 4:3. The number of sci-fi books to the number of biographies is 4:5. If there are 48 sci-fi books what is the total number of books

83. ## phy

At what temperature will the root-mean-square speed of oxygen molecules have the value of 640 m/s? 1 kilomole of oxygen has a mass of 32kg.

84. ## chemistry

calculate the rate of a constant reaction at 293 kelvin when the energy of activation is 103 kilo joules per mole and the rate constant at 273 kelvin is 7.87*10 to the power -7...

85. ## Math

The first ferris wheel was built in1893 in Chicago. It's diameter was 250 feet.how many feet did the ferris wheel rotate with each complete turn?

86. ## pstat.................HELP........................

A diagnostic test for a disease is said to be 90% accurate inthat if a person has the disease, the test will detect it withprobability 0.9. Also, if a person does not have the disease, thetest will report that he or she does noot have it with

87. ## English-Grammar

Decide if the underlined pronoun (I put what was underlined in parentheses) in the sentences below is being used as a subject, a predicate nominative, or an appositive. (He) and Bev are using the new computer. subject (my answer)predicate nominative

88. ## algebra

A sheet of cardboard with an area of 10 square feet is made into a closed rectangular box. The four sides of the box have the same area and two ends have the same area. The area of each of the four equal sides is twice the area of each end. What is the

89. ## algebra 2

A chauffer must decide between driving his clients in the rolls royce or the mercedes benz. the rolls royce costs 1.75 per mile to operate and the mercedes benz costs 2.00 per mile. The chauffer can charge 4.00 per mile for the rolls royce and 6.50 per

90. ## Physics

An animal-rescue plane flying due east at 36.0 m/s drops a bale of hay from an altitude of h = 69.5 m, as shown below. If the bale of hay weighs F = 162 N, what is the momentum of the bale the moment before it strikes the ground? Give both magnitude and

91. ## English

Read each sentence. Write whether the sentence is declarative interrogative imperative or exclamatory 1.Use caution when you cross the street. Imperative 2.Where was Lyndon B. Johnson born? Interrogative? 3.The planet closest to the sun is Mercury.

92. ## phy

A piece of plastic barely floats in water. If it has a mass of 20g, what is its volume?

93. ## chemistry

What is the silver ion concentration in a solution prepared by mixing 385 mL of 0.380 M silver nitrate with 467 mL of 0.409 M sodium chromate? The Ksp of silver chromate is 1.2 × 10-12 I ended up making Ag+ = 2x. = 1.3 x10^-4 Which is incorrect so I'm not

94. ## Chemistry

The half-life of C-14 is 5700 years. If it took seven half lives for a sample of C-14 to decay completely, how many years would have gone by?

95. ## chem.(sci)

___NH3+___O2->N2+H2O (this is not balanced) how many moles of oxygen react with 0.23 moles of NH3? HOW many moles moles of N2 will be produced when reacted with 5 mol of O2?

96. ## English

Read the following sentences write whether each underlined clause is the main clause or a subordinate clause What's the definition of a clause?

97. ## science

A rocket is shot upward from the ground with an initial velocity of 15.5 m/s. How high does the rocket travel?

98. ## math

is eating an apple a physical change

99. ## NSU

Evaluate (if possible) the function at the given values of the independent variable. Simplify the results. (If an answer is undefined, enter UNDEFINED.) f(x)=sin x f(pi)= f(5pi/4) f(fpi/30

100. ## Physics

A patio swing is suspended by two springs, each of which has a force constant of 415 N/m, equivalent to a single spring force constant of 830 N/m. Find the mass of a person sitting on the swing oscillating up and down at a frequency of 0.590 Hz. Please

101. ## Physics

A 1365-kg car moving north at 27.0 m/s is struck by a 2165-kg car moving east at 12.0 m/s. The cars are stuck together. How fast and in what direction do they move immediately after the collision?

102. ## chemistry

calculate the rate of a constant reaction at 293 kelvin when the energy of activation is 103 kilo joules per mole and the rate constant at 273 kelvin is 7.87*10 to the power -7...

103. ## CHEM! (SCIENCE) NEED HELP

How many moles of water will form if the reaction has 9 moles of Cu? how many moles of NO will form if the reaction has 9 moles of Cu? 3Cu+8HNO3->3Cu(NO3)2+4H2O+2NO

104. ## Chemistry

The antifreeze in a car is a 50% by weight solution of ethylene glycol, C2H6O2 in a water solvent. Calculate the boiling point and freezing point of this solution. (For H2O, Kb=0.52 C/m Kf= 1.86 C/m I can't even find the formula for this in my book, please

105. ## Physics

A 50.0 g Super Ball traveling at 27.0 m/s bounces off a brick wall and rebounds at 17.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 4.00 ms, what is the magnitude of the average acceleration of the ball during

106. ## Chemistry

Write the chemical equation showing dihydrogen phosphate and hydrogen phosphate conjugate acid-base relationship. Identify the acid and base. Explain how the equilibrium is shifted as buffer reacts with an acid and reacts with a base.

107. ## calculus

On the graph of f(x)=7sin(7pi x), points P and Q are at consecutive lowest and highest points with P occuring before Q. Find the slope of the line which passes through P and Q

108. ## Chemistry

a 15ml sample of sulfuric acid was titrated against a solution of .0100 mol per litre of sodium hydroxide. to bring about neutralization, 25.00 ml of sodium hydroxide solution was required. calculate the concentration of the sulfuric acid

109. ## math help

A one year subscription to the monthly magazines costs $15.60 the regular newstand price is$1.95 per issue. How much is saved per issue by payin. The subscription price

110. ## Enlish

I'm supposed to be writing an essay and these are the instructions: This semester you read several memoirs, including pieces by Ernesto Galarza and Russell Baker. Return to “Barrio Boy” and “No Gumption” now. How are these two memoirs similar? How

111. ## physics

A block with mass = 5.0 rests on a frictionless table and is attached by a horizontal spring ( = 130 ) to a wall. A second block, of mass = 1.35 , rests on top of . The coefficient of static friction between the two blocks is 0.40. What is the maximum

112. ## math

where N is the number of millions of passenger cars in the United States and t is the number of years after 1940. In what year was the number of passenger cars triple the number of cars in 1940?

113. ## Math

A bag contains 12 slips of paper of the same size. Each slip has one number on it, 1-12. Find P(even number). Find P (a number less than 6). Find P (an odd number). Find P (a number greater than 8).

At issue in the twenty-first century is the trade-off between the necessity of writers, musicians, artists, and movie studios to profit from their work and the free flow of ideas for the public benefit. Movie (and music) industry participants claim that

115. ## science

Th thermosphere is 415km deep. What percent of the atmosphere made up by the thermosphere if the total atmosphere extends 500km.

116. ## math

Determine the energy to heat a cube of gold with a volume of 19.0{\rm cm}^{3} from 15^\circ C to 37^\circ C. (Figure 1) Refer to the tables of densities (Figure 2) and to the table of the specific heats (Figure 3)

117. ## Chemistry

Write the chemical equation showing dihydrogen phosphate and hydrogen phosphate conjugate acid-base relationship. Identify the acid and base. Explain how the equilibrium is shifted as buffer reacts with an acid and reacts with a base.

118. ## Chemistry

If a 100.0 gram sample of a radioactive isotope goes through three half-lives, how much of the original radioactive isotope will remain?

119. ## History

8. What happened to Japanese Americans during World War II? A.) They were forced to leave the country. B.)They stayed in their homes. C.) They all joined the Japanese army. D.) They were sent to internment camps. I think it is C. Thank You.

120. ## physics

A 6.2 g piece of clay is propelled horizontally onto a block of wood with a mass of 18.4 g. The wood block is initially at rest on a 1.75 m tall post. After the collision the wood block will land 2.2 m from the base of the post. Find the initial speed of

306. ## math

is eating an apple a physical change?

307. ## Algebra 1

A car travels on a highway at an average speed of 65 miles per hour. What was the speed in feet per second? (Remember- 1 mile=5280 feet)

308. ## Algebra

how can i break this down .2y+4.2=

309. ## math help!

Solve: 18x=9*10

310. ## Math

What would be the geometric shape of a mansard roof?

311. ## Math

calculate average rate of change 6, Y= -6x^2 - 3, 0

312. ## Bigfoot Reserch Report

Help me i am doing a resherch report on bigfoot. I need some websites that are helpful other than wikipedia.