# Joan

Popular questions and responses by Joan
1. ## calculus

The function f is continuous on the closed interval [0,2] and has values that are given in the table below x = 0| 1 | 2 ____________ f(x) = 1| k | 2 The equation f(x) = 1/2 must have at least two solutions in the interval [0,2] if K = ? The answer is 0,

2. ## chemistry

Europium has two stable isotopes, 151 Eu (150.9198 u) and 153 Eu (152.9212 u). The atomic mass given for Eu is 151.9640 u. What is the percent abundance of 153 Eu ??

3. ## Math

Huan is redesigning his bedroom, which is the shape of a rectangle. a Huan knows the area of his bedroom is 180 square feet. What are all the possible whole number dimensions of Huan’s bedroom?

4. ## Chemistry

1. A gas initially at 10 C must be changed to _____ C to triple the pressure. 2. When a student plotted ln [vapor pressure of a gas] vs. inverse Kelvin temperature, she obtained a straight line with a slope equal to -20000 K. According to the Clausius

5. ## PHYSICS

while exploring a cave, a spelunker starts at the entrance and moves the following distances in a horizontal plane. she goes 75.0 m north, 250 m east, 125 m at an angle theta equal to 30.0 north of east, and 150 m south. find her resultant displacement

6. ## statistics

A score that is 10 points below the mean corresponds to a z-score of z=-2.00. What is the population standard deviation?

7. ## Algebra 2

How many arrangements are possible using the letters in the word FUZZY if each letter "Z" is distinctly different than the other? How many arrangements are possible if the letter "Z" is interchangeabe with the other? Explain your reasoning.

8. ## Physics

A simple pendulum suspended in a rocket ship has a period To. Assume that the rocket ship is near the earth in a uniform gravitational field. Determine for each of the following statements whether it is correct or incorrect. If the length of the pendulum

9. ## physics

John is listening to a horn. He knows the frequency of the horn is 300 Hz when both he and the horn are at rest. If he hears a pitch of 330 Hz, there are clearly several possibilities. For each of the following statements, indicate whether it is correct or

10. ## History

Can someone tell me what they think of my answer? 1. As industry spread, the British and German governments initiated reforms to improve workers’ lives. What motivated Bismarck to enact reforms in Germany? What kinds of reforms were enacted in Germany

11. ## Math( Can you help me with starting this problem)

How fast does the radius of a spherical soap bubble change when you blow air into it at the rate of 15 cubic centimeters per second? Our known rate is dv/dt , the change in volume with respect to time, which is 15 cubic centimeters per second. The rate we

12. ## PHYSICS 1 ..

as she pick up her riders a bus driver traverses four successive displacements represented by the expression (-6.30 b)i-(4.00 b cos 40)i-(4.00 sin 40)j+(3.00 b cos 50)i-(3.00 b sin 50)j-(5.00 b)j here b represents one city block,a convenient unit of

13. ## chem lab question

1. This experiment separates meat into an acetone-soluble part and an acetone-insoluble part. The calculations are based on the principal components of meat being fat (acetone soluble) and protein (acetone insoluble or fat-free meat in report sheet). More

14. ## Physics

A particle moving along the x-axis has its velocity described by the function v =2t squared m/s, where t is in s. Its initial position is x = 2.8m at t = 0 s. At 2.7s , what is the particle's position?

15. ## algebra

A gardener has 120 ft of fencing to fence in a rectangular garden. one side of the garden is bordered by a river and so it does not need any fencing. a. what dimensions would guarantee a garden with an area of 1350 ft ^2 b. what dimensions would guarantee

Write four arguments that meet the following criteria: Argument 1: The argument has a false premise, but follows good logic. Argument 2: The argument has true premises, but follows poor logic, leading to a false conclusion. Argument 3: The argument has

17. ## Math

A gardener has 120 ft of fencing to fence in a rectangular garden. one side of the garden is bordered by a river and so it does not need any fencing. 1. what dimensions would guarantee a garden with an area of 1350 ft^2? 2. What dimensions would guarantee

18. ## math

what is the ratio of 36cm to 9dm

19. ## chemistry

water and ammonia have different molar heats of vaporization. the best interpretation at the molecular level is that water molecules

20. ## chemistry

describe briefly how the particular structure of a neuron relates to it's function in the body

21. ## Chemistry

Predict whether the equivalence point of each of the following titrations is below, above, or at pH 7: Pyridine titrated with nitric acid

22. ## Science

An astronaut is walking in space and his jetpack runs out of fuel. How can he use his empty pack to get back to the space station?

23. ## Physics

Two people are carrying a uniform 788.0 N log through the forest. Bubba is 2.0 m from one end of the log (x), and his partner is 1.1 m from the other end (y). The log is 6.2 m long (z). What weight is Bubba supporting?

24. ## chemistry question on fats

. This experiment separates meat into an acetone-soluble part and an acetone-insoluble part. The calculations are based on the principal components of meat being fat (acetone soluble) and protein (acetone insoluble or fat-free meat in report sheet). More

25. ## economics

Questions from Andreas Software Business A. How many software programs should Andrea sell to make the most profit? __________ What would her profit be? ___________ What is the marginal revenue for this number of programs? ____________ The marginal cost?

26. ## Science: Physics

A physics teacher shoots a .30 caliber rifle at a 0.47 kg block of wood. The rifle and wood are mounted on separate carts that sit atop an air track (like a linear air hockey table--ie. frictionless). The 5.7 kg rifle fires a 27 gram bullet at 227 m/s in

27. ## Physics

Children sled down a 45 m long hill inclined at 26 degrees. At the bottom, the slope levels out. If the coefficient of friction is 0.1, how far do the children slide on the level ground?

Hello! Can someone please help me out for this question? The loudness, L, of a sound in decibels can be calculated using the formula L= 10 log(I/ F) where I is the intensity of the sound in watts per square metre and F= 10^ -12 . A singer is performing to

29. ## math

the angle of elevation of the top of a radio mast from a point due east of it and 96m away from its base is 30degrees. from another point due west of the mast, the angle of elevation of the top is 60degrees. calculate the distance of the second point from

30. ## Physics

A 17kg child slides down a 2.7m -high playground slide. She starts from rest, and her speed at the bottom is 1.8 m/s. What is the change in the thermal energy of the slide and the seat of her pants?

31. ## chemistry

8750 g of a compound which contains only carbon, hydrogen, and nitrogen were burned in oxygen to produce, 2.1930 g of N2O4 , and 2.2900 g of water. What is the empirical formula of the compound? (Hint: do carbon by difference)

32. ## Physics

A car is traveling at 10 m/s. By what factor does the car's kinetic energy increase if its speed is doubled to 20 m/s?

33. ## PHYSICS

The cutting tool on a lathe is given two displacements, one of magnitude 4 cm and one of magnitude 3 cm, in each one of five situations (a) through (e) diagrammed in the figure below. Rank these situations according to the magnitude of the total

34. ## physics

A steel ball of mass m=5 g is moving at a speed of 250 m/s toward a large mass M=2.2 kg which is connected to a relaxed spring, as shown below. When the ball reaches the large mass it collides and bounces off without losing any kinetic energy. The large

35. ## physics

How much heat is required in order to change 5 g of ice at -15 degree to steam at 150 degree?

36. ## physics

A uniform steel chain 20 m long and with a mass of 5 kg per m, hangs vertically. Compute the work required to wind it up

37. ## social studies

who is meant by stupa ?

38. ## chemistry

Europium has two stable isotopes, 151 Eu (150.9198 u) and 153 Eu (152.9212 u). The atomic mass given for Eu is 151.9640 u. What is the percent abundance of 153 Eu ??

39. ## algebra

a rectangular plot of farmland will be bounded on one side by a river and on the other sides by a single strand electric fence . with 800m of wire at your disposal,what is the largest are you can enclose, and what are its dimensions ?

40. ## UNIVERSITY PHYSICS 1

as she pick up her riders a bus driver traverses four successive displacements represented by the expression (-6.30 b)i-(4.00 b cos 40)i-(4.00 sin 40)j+(3.00 b cos 50)i-(3.00 b sin 50)j-(5.00 b)j here b represents one city block,a convenient unit of

41. ## psychology

"during a heated argument with his father, 15 y/o Jason developed a pralysis of his right arm. Medical examinations can find no physical cause for the paraplysis. Use the psychoanalytical perspective to explain how the paralysis may be Jason's attempt to

42. ## financial accounting

Why is it necessary to prepare formal financial statements if all of the data are in the statement columns of the worksheet? Discuss

43. ## chem101

Which of the following solutes in aqueous solution would be expected to exhibit the LARGEST freezing-point lowering (assuming ideal behavior)? A. 0.1 m NaCl B. 0.2 m CH3COOH C. 0.1 m MgCl2 D. 0.05 m Al2(SO4)3 E. 0.25 m NH3

44. ## chemistry

3. The solubility of BaSO4 at 25C is 9.04 mg/L. Based on this, how many grams and moles of BaSO4 remained dissolved in the 100 mL of solution? What percent of your yield does this represent?

45. ## Calculus

Which of the following series can be used to compute ln(.8)? a) ln(x-1) expanded about x=0 b) lnx about x=0 c) ln x in powers of (x-1) d) ln(x-1) in powers of (x-1) e) none of the proceding I am confused... please help!

46. ## Physics

Children sled down a 45 m long hill inclined at 26 degrees. At the bottom, the slope levels out. If the coefficient of friction is 0.1, how far do the children slide on the level ground?

47. ## math

an airplane flew from a city x on a bearing 225 to another city y a distance 200 km away.It then flew from city y on a bearing of N30 W to city Z a distance of 250 km. calculate 1.the distance from city x to city z correct to the nearest whole number. 2.

48. ## Statistics

. Two cards are drawn at random, without replacement, from a standard 52-card deck. Find the probability that: (a) both cards are the same color (b) the first card is a face card and the second card is black

49. ## math

1.352 pounds is what fraction of a short ton? A. 169/250 B.77/100 C. 2/4 D. 140/223

50. ## History

I need help in history. I have to write a 4-5 paragraph essay on world war one, but I need information. Could someone please summarize the main things that happened in world war one? Please don't write an essay, I just need someone to tell me the very

51. ## physics

A ball on the end of a string is whirled around in a horizontal circle of radius 0.467 m. The plane of the circle is 1.24 m above the ground. The string breaks and the ball lands 2.49 m away from the point on the ground directly beneath the ball’s

52. ## math

In a recent year, of all registered doctors were female. If there were female registered doctors that year, what was the total number of registered doctors?

53. ## Physics doppler effect

A person standing close to a railroad crossing hears the whistle of an approaching train. He notes that the pitch of the whistle drops as the train passes by and moves away from the crossing. The frequency of the approaching whistle is 523 Hz, and drops to

54. ## Algebra

The vertex of a graph is (2,-2) is it a minimum, yes or no?

55. ## mathematics

Hi, I'm not sure if I'm giving the correct answer for this problem. The question states; The values of computers in the years after its purchase date are listed in the following table. Year 0=1500, Year1=1200, Year2=1100,Year3 +1000, Year 4 = 800, Year 5

56. ## Physics

Explosives are used to blow a rock apart. The explosion blows the rock into three fragments. Two fragments go off at a 76 degree angle to each other--a 6.2 kg piece at 26.7 m/s and a 5.5 kg piece at 23.3 m/s. Calculate the speed of the third piece, if it

57. ## physics

A 20 g sample of aluminum at 85 degree is dropped in 500g of water. The resulting temperature of aluminum and water is 25 degree. What is the initial temperature of water?

58. ## English

Which is the group of words is a fragments sentence: A) After the store don't run around. B)After the store. C) Don't run around.

59. ## PHYSICS

HELP. I need to understand this for a test tomorrow. THANKS Consider planet mass of 4.98 E 21 kilograms with a satellite orbitting it at distance of 3.11 E 6 meters from planet's center. Satellite has mass of 369 kilograms. How long (inseconds) does it

60. ## English

I'm dead. I'm in a room with 2 doors. One goes to heaven the other goes to Hell. Infront of each door stands a man. One man can only tell the truth. The other can only tell lies. What question do I ask to get to heaven

61. ## english

1. Rewrite sentences using the Passive They’re going to open the sports complex next week. The sports complex... The USA manufacture a lot of sports equipment A lot of sports equipment... They’re building some tennis courts in the park. Some tennis

The Sweet Candy Shop buys 600 pounds of chocolate covered strawberries at \$5.59 per pound. If a 10% spoilage rate is anticipated, at what price per pound should the strawberries be sold in order to achieve a 60% markup based on cost?

63. ## Chemistry Science

calculate the mass of carbon dioxide that would be produced when one gas of tank of gasoline (use octane) is burned in the air. assume an 80 liter gas tank and 0.703 g/ml as the density of octane

64. ## Physics

A bomb free of outside forces is traveling north when it explodes into exactly three pieces. (Ignore any gas molecules from the explosion that go off in miscellaneous directions.) One piece continues to travel north, while another moves straight up

65. ## chemistry

a balloonist is preparing a trip in a helium balloon. the trip begins in early morning at a temp of 15 degrees Celcius. By mid afternoon, the temp has increased to 30 degrees C. assuming the pressure remains constant at 1.00 atm, for each mole of helium,

66. ## Statistics

In a certain Math class, the probabilities have been empirically determined for various numbers of absentees on any given day. These values are shown in the table below. Find the expected number of absentees in a given day. Number of absentees, x 0 1 2 3 4

67. ## physics

A massless spring with spring constant 16.7 N/m hangs vertically. A body of mass 0.220 kg is attached to its free end and then released. Assume that the spring was unstretched before the body was released. How far below the initial position does the body

68. ## science

a skydiver experiences a downwar force due to gravity of 700 N and an upward force of air resistance of 570 N. The mass of the skydiver is 65 kg. What is the downward acceleration in meters/second squared of the skydiver?

69. ## Physics

A crane is lowering two boxes downward at a constant velocity. The cable from the crane is attached directly to the upper box, m1, which has a mass of 95kg and a second cable hanging from the upper box supports the lower box, m2, which has a mass of 140kg.

70. ## Thermochemistry

A 1.00-g sample of solid calcium was burned in fluorine to give a 1.95 g sample of pure CaF2. The energy given off in this reaction was 30.3 kJ. Given this information, we can say that the heat of formation of 1 mol of CaF2 is

71. ## mathematics of investment

Accumulate 3,200 for 2 years and 6 months at 5 1/2% simple discount.

72. ## PHYSICS

while exploring a cave, a spelunker starts at the entrance and moves the following distances in a horizontal plane. she goes 75.o m north, 250 m east, 125 m at angle theta =30.0 north of east, and 150 m south. find her resultant displacement from the cave

73. ## Chemistry

How much distilled water must be added to .85% solution Of NaCL to make a 70% solution of NaCl

74. ## chemistry

How many grams of Al(NO3)3 are needed to prepare 25.0 mL of a 0.750 M aqueous solution.

75. ## physics

A pendulum consists of a mass m = 0.12 kg hanging from a flexible string of length L. The string is very thin, very light, and does not stretch. It makes small oscillations, with a period of 0.663 s. What is the oscillation frequency of the pendulum? What

76. ## Math

Factorize the following expressions completely. 6x2y3 +18xy + 3x2y2 + 9x y2 – x2 + 8y + 16 64x6 – y6

77. ## Riddle

What come once in a moment, twice in a minute and never in a thousand years?

78. ## Math

First Bank charges \$4.50 per month for a basic checking account plus \$0.15 for each check written. Citizen's Bank charges a flat fee of \$9. How many checks would you have to write each month in order for the cost to be the same at both banks?

In October, a hardware store purchased snow shovels for \$8 each. The original markup was 50% based on the selling price. In December the store had a sale and marked down the shovels by 20%. By January 1, the sale was over and the shovels were marked up to

Beacon electronics advertised a portable TV set on sale for \$272.49 after a 35% markdown from the original price. What was the original price of the TV set? Round to nearest cent

81. ## stats

If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, what percentage of light bulbs have a life less than 2500 hours? A) About 25% B) About 50% C) About 75% D) About 68%

82. ## Finance

listing the different sources of short-term financing. Discuss the characteristics of each source and explain why a company might choose one over the other.

83. ## Physics

An electrical motor is designed to operate on 34 V at 1.3 A. How much resistance must be connected in series to this motor, if you wish to plug it in to a 120 V outlet?

84. ## mathematics of investment

on what day will 8,000 earn 180 interest when invested on April 25, 2002 at 9% simple interest? use ordinary interest and actual time.

Treadmill, cost is x, amount of markup \$880.00, selling price of \$2,335.00, what is percent markup based on cost?

86. ## Math

The Soft Step Floor Company purchases carpeting for \$5.12 per sq. yard and marks it up 55% based on the selling price. What is the selling price per sq. yard? Round to nearest cent

87. ## Chemistry

Predict whether the equivalence point of each of the following titrations is below, above, or at pH 7: Pyridine titrated with nitric acid

88. ## math

One card is selected at random from an ordinary set of 52 cards. Find the probability of each of the following events: a spade and a 5 are drawn. a jack is not drawn. Thanks for any help with this.

89. ## chemistry

name the element found in small amounts in the body, that is needed to make homoglobin for oxygen transport.

90. ## chemistry

what are 4 elements that make up bulk of living matter?

91. ## Calculus!!!

I need your help... I've posted this question a while ago but no one has answered it yet. Please please help me. Which of the following series can be used to compute ln(.8)? a) ln(x-1) expanded about x=0 b) lnx about x=0 c) ln x in powers of (x-1) d)

92. ## mathematics of investment

Mark Lopez went to his bank to find out how long it will take for P10,000 to amount to P10,700 at 12% simple interest. Express answers in days.

93. ## Chemistry

How much energy(in calories)would it take to heat 13g of water 2 degrees Celsius?? 1.00cal/1g C = 13 x 2 = 26 Calories Is that right?

The Flower Power Bakery makes 200 cherry cheesecakes at a cost of \$2.45 each. If a spoilage rate of 5% is anticipated, at what price should the cakes be sold to achieve a 40% markup based on cost?

95. ## help science

which has moroe bouyancy when dpped in water ? iron ? aluminiom ?

96. ## chemistry

7.25 g of iron were reacted with sulfur until the product reached a constant mass of 13.50 g. If the experimental molecular mass of the product was measured as 572 u, what is the molecular formula of the product? What is the actual molecular mass of the

97. ## chemistry

7.25 g of iron were reacted with sulfur until the product reached a constant mass of 13.50 g. If the experimental molecular mass of the product was measured as 572 u, what is the molecular formula of the product? What is the actual molecular mass of the

98. ## chem!

i cant figure this one out! :( a balloonist is preparing a trip in a helium balloon. the trip begins in early morning at a temp of 15 degrees Celcius. By mid afternoon, the temp has increased to 30 degrees C. assuming the pressure remains constant at 1.00

99. ## stats homework

the monthly demand for a certain product is a normal random variable with a mean of 50 and standard deviation 10 a) if you have 60 units on a stock at the beginning of the month, what is the probability you will still have stock remaining at the end of the