Jen

Most popular questions and responses by Jen
1. Statistics

One of the questions in the Pew Internet & American Life Project asked adults if they used the Internet, at least occasionally. The results showed that 454 out of 478 adults aged 18 - 29 answered yes; 741 out of 833 adults aged 30 – 49 answered yes; 1058

2. physics

Suppose you had two small boxes, each containing 1.0 g of protons. (a) If one were placed on the moon by an astronaut and the other were left on the earth, and if they were connected by a very light (and very long!) string, what would be the tension in the

3. physics

A model rocket leaves the ground, heading straight up at 47 m/s. (a) What is its maximum altitude? m What are its speed and altitude at each of the following times? (b) 1 s m/s m (c) 4 s m/s m (d) 8 s m/s m

4. Calculus

The line that is normal to the curve x^2=2xy-3y^2=0 at(1,1) intersects the curve at what other point? Please help. Thanks in advance. We have x2=2xy - 3y2 = 0 Are there supposed to be 2 equal signs in this expression or is it x2 + 2xy - 3y2 = 0 ? I'll

5. stastics

If 1.5% of the bolts made by an automotive factory are defective, what is the probability that in a shipment of 200 bolts, there are 6 defective bolts? Place your answer, rounded to four decimal places, in the blank.

6. Physics

An astronaut is inside a rocket that is blasting off vertically from the launch pad. You want this rocket to reach the speed of sound (331 m/s) as quickly as possible, but you also do not want the astronaut to black out. Medical tests have shown that

7. The End of the Cold War

1. Which is the best example of how Reagan dealt with the Soviet Union from a position of strength? A. development of the strategic defence initiative B. U.s withdrawl of the salt II treaty from senate approval C. Reagan condemning martial law of Poland D

8. Physics

A 15.0 kg box is released on a 32 degree incline and accelerates down the incline at 0.30m/s sqaured ? find the friction force impeding its motion. What is the coefficient of kinectic friction?

9. physics

A merry-go-round in a playground has a mass of 200 kg and radius of 1.50 m. You apply a force F = 23 N tangentially to the edge of the merry-go-round for a time of 6.5 s. The moment of inertia of the merry-go-round is 1/2(mR2). What is the angular

10. History

Zhou rulers claimed that they had won the Mandate of Heaven because they How did the zhou king control his vast kingdom What did zhou artisans discover

11. chem 15

The hardness of water (hardness count) is usually expressed as parts per million (by mass) of calcium carbonate. What is the molar concentration of calcium ions in a water sample with a hardness count of 175ppm?

12. statistics

Go to a local library; collect a sample of books consisting of the ages of book (based on copyright dates). Plan and describe the sampling procedure, then use the results to construct a confidence interval estimate of the mean age of all books in the

13. physics

A 2500N pile-driver ram falls 10m and drives a post 0.1m into the ground. Find the average impact of force on the ram.

14. Statistics (Check Work)

Can Someone help me with these 2 problems? I am certain I am solving them correctly, but for some reason the computer keeps marking my answers as incorrect. Question 1: Minnesota had the highest turnout rate of any state for the 2012 Presidential election.

15. Exponents-word problem

A culture starts at 8600 bacteria. After one hour the count is 10,000. Find a function that models the number of bacteria n(t) after t hours. The answer is n(t) = 8600e^.1506t Where does this 0.1506 come from? Thanks. n(t) = 8600 e^(kt), where k is an

16. Statistics

Can someone please help me answer these questions? I have tried every method I know and the computer still keeps marking the answers as incorrect. Thanks for the help! 1) If the number of 18-34 year olds sampled is equal to the value identified in part

17. Math

A coin is biased so that a head is twice as likely to occur as a tail. If the coin is tossed 3 times, what is the probability of getting 2 tails and 1 head? What do you mean by biased in probability?

18. Chemistry

Write the net ionic equation for the equilibrium that is established when ammonium nitrate is dissolved in water. (Use H3O+ instead of H+)

19. math

Using the numbers 2,3,5,10,24 write two separate equations that equal 120

20. Chemistry

How many electrons in an atom could have these sets of quantum numbers? n=2 n=5, l=3 n=6, l=1, ml=-1

21. College Physics

A fisherman notices that his boat is moving uo and down periodically, owing to waves on the surface of the water. It takes 2.5 s for the boat to travel from its highest point to its lowest, a total distance of 0.62 m. The fisherman sees that the wave

22. calculus

If y is a differentiable function of x, then the slope of the tangent to the curve xy - 2y + 4y^2 = 6 at the point where y=1 is ...... How do I do this? Thanks. xy - 2y + 4y^2 = 6 ---> d[xy - 2y + 4y^2] = 0 ---> xdy + ydx - 2dy + 8ydy = 0 ---> (x + 8y -

23. CHEMISTRY HELP

1) The specific heat of solid copper is 0.385 J/g(C). What thermal energy change occurs when the temperature of a 34.10 g sample of copper is cooled from 35.7 degrees Celsius to 13.9 degrees Celsius? Answer: -286.3 J This amount of heat is used to melt

24. Chemistry

In Millikan's experiment, the charge on each drop of oil was measured in coulombs. Imagine the same experiment, but with charges measured in a fictitious unit called a zeet (). Drop Charge () A 1.38×10−14 B 3.22×10−14 C 3.68×10−14 D 4.14×10−14

25. Eng

Which statement is most accurate regarding the speaking-writing connection? A. To own a word, write it over and over again. B. Written words seldom reflect the words people use when they speak. C. To own a word, speak it. D. The words used by writers are

26. chemistry

What atomic or hybrid orbitals make up the sigma bond between As and F in hexafluoroarsenate ion, AsF6- ? orbital on AS:? orbital on F:?

27. AP chem

A 1.25-g sample contains some of the very reactive compound Al(C6H5)3. On treating the compound with aqueous HCl, 0.951 g of C6H6 is obtained. Al(C6H5)3(s) + 3HCl(aq) --> AlCl3(aq) + 3C6H6(l) Assuming that Al(C6H5)3 was converted completely to products,

28. chemistry

In clinical lab reports, some concentrations are given in mg/dL. Convert a Ca2+ concentration of 3.5 mg/dL to weight/volume percent.

29. Statistics

A company manufactures calculators in batches of 64 and there is a 4% rate of defects. Find the probability of getting exactly three defects in a batch.

30. physics

Two equal point charges of +3.00 * 10^ -6 C are placed 0.200 m apart. What are the magnitude and direction of the force each charge exerts on the other?

31. science-plz help this is so urgent!

8. a) after the oceans, where is the next largest reserve of water found? b) does this reserve contain salt water or fresh water? Fresh water lakes on the surface. Glaciers and icecaps account for a greater amount of water than lakes swamps and rivers if

32. solving trig. equations

tan(3x) + 1 = sec(3x) Thanks, pretend 3x equals x so tanx + 1 = secx we know the law that 1 + tanx = secx so tanx + 1 becomes secx and... secx = secx sec(3x) = sec(3x) [just put 3x back in for x- you don't really have to change 3x to x but it kinda makes

33. math

From a bag of peanuts, phillip took 1/3, then joy took 1/4 of the remaining, brent took 1/2 of the remaining, and preston took 10. There were 71 peanuts remaining....how many were there to start?

34. Civics

which of the following is not an authoritarian form of government? A. Totalitarianism B. Absolute monarchy C. Dictatorship D. Direct democracy Answer is "C"

35. chemistry

why should excess alkali be avoided in the ferric chloride test for acetic acid and benzoic acid?

36. college physics

A 0.25 kg skeet (clay target) is fired at an angle of 30 degrees to the horizon with a speed of 25 m/s. When it reaches the maximum height, it is hit from below by a 15 g pellet travelling upward at a speed of 200 m/s. The pellet is embedded in the skeet.

37. Poetry

What is the tone of the poem "Litany" by Billy Collins? Is there some sort of message or is he just being weird? Since the first two lines were written by that Belgian guy, I would imagine he is making fun of love poems. Am I in the right direction?

38. chemistry

Question 1. A Compound Containing 3 Atoms Of Carbon & 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The 2 End Products Of This Equation Are Carbon Dioxide &water. What Element Should You Look At 1st In Balancing This Equation? Choose

39. Chemistry

Hydrogen sulfide is an impurity in natural gas that must be removed. One common removal method is called the Claus process, which relies on the reaction: 8 H2S(g) + 4 O2(g)--> S(l) + 8 H2O(g) Under optimal conditions the Claus process gives 98% yield of S8

40. physics

A Carnot engine is operated between two heat reservoirs at temperatures 520 K and 300 K. (a) If the engine receives 6.45 kJ of heat energy from the reservoir at 520 K in each cycle, how many joules per cycle does it reject to the reservoir at 300 K? (b)

41. physics

A refrigerator has a coefficient of performance of 2.25, runs on an input of 95 W of electrical power, and keeps its inside compartment at 5 degrees celsius. IF you put a dozen 1.0 L plastic bottles of water at 31 degrees celsius in the refrigerator, how

42. Civic

One factor determining the number of representatives for a given congressional district is the distribution of _____ within the state A. registered voters B. population C. jobs D. wealth Answer is "B"

43. math

A ball is thrown from the edge of a cliff with an initial velocity of 60·m/s upward. Answer the following questions using + (upward) and - (downward) to indicate the direction of the velocity. Ignore air resistance and assume the ball does not hit the

44. Chemistry

If the heat from burning 5.800 g of C6H6 is added to 5691 g of water at 21 °C, what is the final temperature of the water? 2C6H6(l) +15O2 (g)----> 12CO2(g)+6H2O(l) +6542

45. Math

If you where to plot the following points for two dimensional X and Y axis; POINT 1 (1, 0) POINT 2 (1, -1) POINT 3 (1, -2) POINT 4 (2, 2) then draw lines to connect from point 1 to point 2 to point 3 to point 4 QUESTION: the lines that you would have drawn

46. Algebra

Use substitution to determine whether the ordered pair (–2, –3) is a solution of the equation x2 – y = 7. Show some work. Be sure to state your conclusion about whether the ordered pair is a solution or not.

47. polynomials & rational function

A drug is administered to a patient and the concentration of the drug in the bloodstream is monitored. At time t >= 0(in hours since giving the drug) the concentration is given by(in mg/L) c(t) = 5t / (t^2+1) Graph the function. From the graph, how do I

48. Social studies

2. According to the map, how did people first arrive in North America? (A). They traveled by boat from Africa. (B). They sailed across the Atlantic ocean. (C). They migrated from South America to North America. (D). They walked or paddled from Asia to

49. physics

Calculate the mass of nitrogen present in a volume of 3000 cm^3 if the temperature of the gas is 22 degrees Celsius and the absolute pressure is 2.00 * 10^-13 atm, a partial vacuum easily obtained in laboratories. The molar mass of nitrogen (N2) is 28

50. Eng B

It's most accurate to say that interpretative literature A. is intended to meet the reader's expectations. B. weaves exciting action around a standard formula. C. contains or suggests universal truths. refers to today's hot topics. Answer is A

51. Latin I

1. Estne in Campania? a. where is Campania? b. he is in Campania, isn't he? c. he is not in Campania, is he? d. Is he in Campania? 2. Vesuviusne populum terruit? a. did vesuvius frighten the people? b. Vesuvius did not frighten the people, did it? c.

52. Social studies

5. What effect on the Columbian exchange does this image illustrate? (A). The population boom of domesticated animals that escaped into the wild. (B). The conversion of the physical environment.*** (C). The introduction of milk cows to the North Americans

53. economics

a firm is planning to manufacture a new product. the sales department estimates the quanity that can be sold depends on the selling price. as the selling price is increased, the quantity that can be sold decreases. they estimate: P=\$35-0.02Q where

54. Calculus

1. Use a graph to estimate the limit. Use radians unless degrees are indicated by θ°. (Round your answer to four decimal places.) lim θ → 0 θ/tan(7θ) 2. Assuming that limits as x → ∞ have the properties for limits as x → c, use algebraic

55. Physics

An 11.98-gram sample of zinc metal is placed in a hot water bath and warmed to 78.4°C. It is then removed and placed into a Styrofoam cup containing 50.0 mL of room temperature water (T=27.0°C; density = 1.00 g/mL). The water warms to a temperature of

56. Algebra

The arch of the bridge below is half an ellipse, a "semi-ellipse". The arch is 148m long and has a height of 48m at the center. The height of the arch is 10m at point p. What is the distance from p to the center?

57. math

Luanne estimates the sum of 39 + 15 is about 40 + 15, or 55. Jacob estimates the sum of 39 + 15 is 40 = 20 or 60 which one is closer to the exact sum?

58. Calculating distance(law of cosines)

Observers P and Q are located on the side of a hill that is inclined 32 degrees to the horizontal as shown(picture given). The observer at P determines the angle of elevation to a hot air balloon to be 62 degrees. At the same instant the observer at Q

59. Neutons Thrid law

3. A force of 36 N gives a mass m1 an acceleration of 4.0 m/s2. The same force gives a mass m2 an acceleration of 12 m/s2. What acceleration will this force give to m1 and m2 if the two masses are fastened together? {3.0 m/s2}

60. Finance

You want to purchase a new condominium that costs \$287,500. Your plan is to pay 25 percent down in cash and finance the balance over 15 years at 3.75 percent. What will be your monthly mortgage payment including principal and interest? \$1,568.07 \$1,333.33

61. Chemistry

Suppose you have a strong peak at 2230 cm–1. What is the wavelength of the radiation that was absorbed?

62. Latin I

“Arms and the man I sing”—With these words Virgil began his poem about the origins of the Rome. The “wars” were not only the famous Trojan War, but also the wars in Italy; “the hero” is Aeneas, who traveled from Troy to a new town, New Troy,

63. d/dx

d/dx( ln |sin(pi/x)| ) = ? Thanks. If those are absolute value signs, the derivative will not exist when sin (pi/x) = 0, because of the sign change that occurs there. Assume sin (pi/x) > 0 Let u(x) = pi/x and v(x) = sin x, and use the chain rule. d/dx ln

64. chemistry

1. Which of the following statements about the cell theory is correct? a) All living organisms are made up of one or more cells. b) All cells arise from other, pre-existing cells c) All eukaryotic cells contain symbiotic prokaryotes. d) All prokaryotic

65. physics

A negative charge of -0.550 uC exerts an upward 0.200 N force on an unknown charge 0.300 m directly below it. (a) what is the unknown charge (magnitude and sign)? (b) What are the magnitude and direction of the force that the unknown charge exerts on the

66. College Physics

Tarzan spies a 35kg chimpanzee in severe danger, so he swings to the rescue. He adjusts his strong, but very light, vine so that he will first come to rest 4.0 s after beginning his swing, at which time his vine makes a 12 degree angle with the vertical.

67. Physics

A stone is dropped from the top of a cliff. It is seen to hit the ground below after 3.90 s. How high is the cliff?

68. Statistics

A sample of 12 measurements has a mean of 34 and a standard deviation of 4.5. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 34 each. A. Find the mean of the sample of 14

69. physics

For a scene in a movie, a stunt driver drives a 1.50×10^3kg SUV with a length of 4.00m around a circular curve with a radius of curvature of 0.333 km. The vehicle is to be driven off the edge of a gully 10.0 m wide, and land on the other side 2.96 m below

70. geography

why is Washington DC. included in the southeast region?

71. physics

An astronaut on a distant planet wants to determine its acceleration due to gravity. The astronaut throws a rock straight up with a velocity of 13.5 m/s and measures a time of 21.8 s before the rock returns to his hand. What is the acceleration due to

72. physics

an unstretched hanging spring is 50cm long. suspending a 100N weight from it makes its lenght 60cm. Adding another 100N weight will make the spring -- 60cm, 70 cm, 80 cm, 100 cm, or 120 cm. No idea how they came up with any of the five ??? My answer was

73. Chemistry

Question 1. A Compound Containing 3 Atoms Of Carbon & 8 Atoms Of Hydrogen Is Combined In A Reaction With Oxygen Molecules. The 2 End Products Of This Equation Are Carbon Dioxide &water. What Element Should You Look At 1st In Balancing This Equation? Choose

74. Physics

A certain freely falling object requires 1.50 seconds to travel the las 30.0 meters before it hits th ground. From what height above the ground did it fall?

75. Physics

A car accelerates from 0 to 60 miles per hour in 6.5 seconds. Determine the distance traveled in this time and the acceleration. Assume constant acceleration.

76. Science - Physics

A meter stick is balanced at the 50-cm mark. You tie a 20-N weight at the 20-cm mark. At which mark should a 30-N weight be placed so that the meter stick will again be balanced?

You are planning to close off the corner of the first quadrant with a line segment 20 units long running from (a,0) to (0,b). Show that the area of the triangle enclosed by the segment is largest when a=b From applications of derivatives...this is really

78. chemistry

A dynamic equilibrium, Ag2CO3(s) 2Ag+(ag) , CO3 2- (ag), what affect does the addition af HCl have on the system? Does it cause a shift?

79. science

An elevator cab in NY Marriott has a total run of 190 m . IT's max speed is 305m/min Its acceleration and deceleration both have a magnitude of 1.22m/s^2 a) how far does the cab move while accelerating to full speed from rest? b) How long does it take to

80. linear algebra

what is the basis of a subspace or R3 defined by the equation 2x1+3x2+x3=0 I know the basis is vectors and but how do you get that?

81. Chemistry IR Spectroscopy

Sort the compounds: conjugated or non conjugated. -but-2-enoic acid -butanoic acid -hex-4-en-3-one -hexan-3-one

82. Neutons Second Law

A 1200 kg car travelling at 50 km/h experiences an air resistance of 5000 N and road friction of 2200 N. If the wheels push with a force of 7500 N, what is the car's acceleration?

83. Chemistry

Assume your sample spots are 1 cm above the bottom of the TLC plate. What happens if you put the plate in a developing chamber that has 1.2 cm of developing solvent? A. The solvent will move up the plate by capillary action faster. B. The sample spots will

84. chemistry

use standard enthalpies of formation to calculate delta Hrxn for the following reaction. 2H2S(g)+3O2(g)-->2H2O(l)+2SO2(g) express the answer using four significant figures Delta Hrxn = ? kJ

85. Latin I

Primo (at first), natura ab viris adorabatur. Antequam (afterwards), viri et feminae deos et deas laudabant. Tum (Then) animas naturae laudabant. Animae naturae timebantur. Viri rogabant: De quo luna (moon) venit (comes)? De quo sol (sun) venit (comes)?

86. math

Carl drove from his house to work at an average speed of 35 miles per hour. The drive took him 25 minutes. If the drive home took him 30 minutes and he used the same route in reverse, what was his average speed going home?

87. AP Chemistry

The formulas for ethanol and ammonium nitrate are C2H5OH and NH4NO3. In what respects are these formulas and compounds different? Am I supposed to say that there are different elements that make up the compounds?

88. inverse

If f(x)=cosx + 3 how do I find f inverse(1)? Thanks y = cos(x) + 3 the inverse of this is x = cos(y) + 3 solve for y and you have your inverse The cos function only has a range of [-1,1], so the range of f(x) is [2,4]. this means f inverse of 1 doesn't

89. Chemistry

Assume the solubility of benzoic acid in ice-cold water is 1.70 g/L and the solubility of benzoic acid in hot water is 68.0 g/L. Calculate the minimum volume of water (in mL) needed to recrystallize 0.950 g of benzoic acid.

90. chemistry

A 100.0 ml sample of 0.300 M NaOH is mixed with a 100.0 ml sample of 0.300 M HNO3 in a coffee cup calorimeter. Both solutions were initially at 35.0 degrees celcius; the temperature of the resulting solution was recorded at 37.0 degrees celcius. Determine

91. Stats

In each of the four examples listed below, one of the given variables is independent (x) and one of the given variables is dependent (y). Indicate in each case which variable is independent and which variable is dependent. I. Rainfall; Crop yield II. Taxi

92. History

Hi I'm honestly stuck on these 3 questions, I looekd on wiki and everything. Please Please help me out.. What action did President Polk take that resulted in the war between the United States and Mexico? He ordered troops to invade Mexico and capture Vera

93. Math

Write a negation of the statement. Not all people like football.

94. rate of change

A missile rises vertically from a point on the ground 75,000 feet from a radar station. If the missile is rising at the rate of 16,500 feet per minute at the instant when it is 38,000 feet high, what is the rate of change(in radians per minute) of the

95. math 9

Given Parallelogram ABCD with AB=(3x-5)cm, BC=(2y-7)cm, Cd=(x+7)cm, AD=(y+3)cm

96. physics

A woman on a bridge 77.4 m 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 7.07 m more to travel before passing under the bridge. The stone

97. Chemistry

Which of the following solutions is the most basic? (a) 0.6 M NH3, (b) 0.150 M KOH, (c) 0.100 M Ba(OH)2. Explain.

98. physics

Neurons are components of the nervous system of the body that transmit signals as electrical impulses travel along their length. These impulses propagate when charge suddenly rushes into and then out of a part of the neutron called an axon. Measurements