1. physics

A 5.00×105-kg subway train is brought to a stop from a speed of 0.500 m/s in 0.400 m by a large spring bumper at the end of its track. What is the force constant k of the spring?

2. science

The radius of the Earth is approximately 3,960 miles. Find the approximate surface-area-to-volume ratio of the Earth. A. 0.00025 B. 0.00076 C. 1,320 D. 11,880

3. Calculus

The radioactive element polonium decays according to the law given below where Q0 is the initial amount and the time t is measured in days. Q(t) = Q0 · 2-(t/140) If the amount of polonium left after 700 days is 45 mg, what was the initial amount present?

Polluted water from a factory flows into a pond. The concentration of pollutant, c, in the pond at time t minutes is modelled by the equation c(t)=8-8000(1/1000+2t) where c is measured in kg/m3. When will the concentration of pollutant in the pond reach 6

5. math

Number of dinners = 125 Individual portion = 8 oz. Size of can = 32 oz. Number of cans required = I got 31.25 buttt you can't have 31.25 cans lol !

6. Physics

At a certain harbour, the tides cause the ocean surface to rise and fall a distance d(from highest level to lowest level) in simple harmonic motion, with a period of 12.5h. How long does it take for the water to fall a distance 0.250d from its highest

7. Physics

Excess electrons are placed on a small lead sphere with mass 8grams so that its net charge is -3.20*10^9C. a) Find the number of excess electrons on the lead sphere b) How many electrons are there per lead atom

8. physics

A 5-kg box is pushed across a horizontal floor by a 20-N force that is angled 30 degrees below the horizontal. What is the coefficient of kinetic friction between the box and the floor if the box is pushed at a constant speed?

9. physics

A 53.0-kg person jumps from rest off a 12.0-m-high tower straight down into the water. Neglect air resistance. She comes to rest 3.00 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This

10. physics

A small cylinder rests on a circular turntable that is rotating clockwise at a constant speed. The cylinder is at a distance of r = 12 cm from the center of the turntable. The coefficient of static friction between the bottom of the cylinder and the

11. math

OMG I CAN NOT get this !!!! Purchase price of article = \$495 Down payment = \$50 Number of payments = 36 True annual interest rate = 18% Monthly payment amount = \$

asked by sarah (I DON'Tget this)
12. math

Loan Amount: \$15,000 Method of payment: discount basis Amount of Interest : \$650 Term of loan: 1 year Effective Rate of Interest (to the nearest tenth): I tried to work this out but I got it completely WRONG !!

13. College Algebra (Urgent)

The demand equation for a product is p = 60 – 0.0004x, where p is the price per unit and x is the number of units sold. The total revenue for selling x units is shown below. Revenue = xp = x(40 – 0.0004x) How many units must be sold to produce a

14. statistics

Miller (2008) examined the energy drink consumption of college undergraduates and found that males use energy drinks significantly more often than females. To further investigate this phenomenon, suppose a researcher selects a random sample of n=36 male

15. math

OMG I CAN NOT get this !!!! Purchase price of article = \$495 Down payment = \$50 Number of payments = 36 True annual interest rate = 18% Monthly payment amount = \$ The formula is I= 2YC ________ M(N+1) y = the number of payments made in a year. m = the

16. Calculus

During a flu epidemic, the number of children in the Woodbridge Community School System who contracted influenza after t days was given by the following. Q(t) = 8000/(1+199 e^(-0.6 t)) (a) How many children were stricken by the flu after the first day?

17. math

What is the unit rate? 1500 meters in 6 seconds?

18. Chemistry

Explain why the FeCl3-KCI-HCl solution was used as a reference solution. Suggest a procedure you could follow to determine whether it was necessary to use this solution as a reference or whether distilled water would have been just as satisfactory.

19. Math

A picnic cooler contains different types of cola.12 regular, 8 cherry, 6 diet, 8 caffeine free, 10 diet vanilla, and some diet cherry. U pick a can of cola without looking at its type. There is a 44% chance that the drink selected is diet. How many diet

20. Physics

A hollow spherical iron shell floats almost completely when submerged in water. The outer diameter is 50.0cm, and the density of iron is 7.87g/cm^3. Find the inner diameter.

21. physics

A 54.5-kg passenger in the back seat of a van is wearing a seat belt when the van runs into a stone wall. The van is originally moving at 12.6 m/s. The front end of the van collapses 0.624 m as the van comes to rest. (a) Determine the passenger’s kinetic

22. Math

A soccer ball is kicked from the ground. After travelling a horizontal distance of 25m, it just passes over a 2m tall fence before hitting the ground at a horizontal distance of 35m. a) Determine an equation to represent the height of the ball relative to

23. Chemistry

Suppose the solubility of PbCl2 (s) 5.6 x 10^-2 M. Calculate the ksp

24. Chemistry

Calculate the equilibrium constant, k a reaction with delta G= -32.5 kj/mol at 25 degrees C

can you plz correct it Howdy comrades! Shouldn’t surprise anyone that we took a beating this year, given the insane pricing moves our knucklehead competitors have been making. I mean how those clowns can keep turning a profit is beyond me, what with

26. Chemistry

Calculate delta G of a reaction with equilibrium constant, K= 9.5 x 10^5 at 25 degrees C

27. Chemistry

1. calculate the volume of concentrated HNO3 (68%)that is needed to prepare stock solution 0.25M in 1000mL volumetric flask. (density HNO3 = 1.513 g/cm^3) 2. from above stock solution, determine volume needed to dilute to 500mL volumetric flask that

28. science

what happens when lead nitrate react with potassium hydroxide

29. physics

An automobile has a mass of 2150 kg and a velocity of +18 m/s. It makes a rear-end collision with a stationary car whose mass is 1850 kg. The cars lock bumpers and skid off together with the wheels locked. What is the velocity of the two cars just after

Calculate the freezing point of an aqueous solution formed by dissolbing 4.22 g of KCl in 25.00 mL of water. Kf for water is (-1.86 degree C/m). Assume density of water is 1.00 g/mL. (Hint: Use the ideal van't Hoff factor, i).

31. physics

A charge of -5.4X10^-7 exerts an upward .250 N force on an unknown charge .260m directly below it. What is the unknown charge?

32. differential calculus

a pc of wire 10feet long is cut into 2 pcs. one piece is bent into the shape of a circle and the other into the shape of a square. how should the wire be cut so that the combined area is as large as possible?

33. statistic homework

suppose that a detective file in new orleans has 63 current unsolved murders. what is the probability that at least 35 of the victims knew their murders

34. CHEMISTRY

How to prepare a 500ml 0.2M NaOH solution from 2.0M NaOH solution

35. Biology

1. A theory and a hypothesis are different in that: A. you must have a theory before you can form a hypothesis. B. a theory is developed as a result of broad agreement among scientists and a hypothesis is a much less substantiated idea. C. a theory is much

36. Chemsitry

Calculate the molar mass of an unknown molecular compound mixed with solid camphor C10H16O, heated and then cooled giving the following data. show all steps in calculation. mass of unknown: 0.195 g Tf(camphor)= 179.8 degree C Kf(camphor)=-40.0 degree C/m

37. math

nemo is swimming 47 feet below sea level . he ascends 16 feet in the water . what is nemos current position ?

38. Physics

Calculate the vertical distance an object dropped from rest covers in 12 seconds of free fall. (The unit of measure for distance is the meter, written as m.)

39. British Literature

what is the theme of mary, lady chudleight's poem "to the Ladies>" what advice does she give to women

40. Chemistry

If the solubility of CaF2 (s) in water is 5.0 x 10^-3. The solubility will be A. The same in 0.10 M NaF B. less than 0.10 M NaF C. Higher in 0.10 M NaF D.None of the above

41. Algebra 2

At 1:00 a.m., a homicide detective found the reading of a corpse's body temperature to be 88 degrees Fahrenheit. One hour later, the body temperature is 83 degrees Fahrenheit. If the body has been in a 74 degree Fahrenheit room since its death, what is the

Calculate the molar mass of an unknown molecular compound mixed with solid camphor C10H16O, heated and then cooled giving the following data. show all steps in calculation. mass of unknown: 0.195 g Tf(camphor)= 179.8 degree C Kf(camphor)=-40.0 degree C/m

A particle moves with a fixed acceleration 3 m/s^2. If its initial velocity is s(0)=0: a) Find its velocity function. b) How long does it take for the particle to reach the velocity 14 m/s^2? c) Find the distance the particle traveled when its velocity

44. Physics

Suppose this dude wants to be able to touch the rim of a basketball goal. The rim is 3.048 m above the ground. The dude can reach up 2.45 m with his feet on the ground. (a) If the dude can achieve a liftoff speed of 2.80 m/s, what is his maximum upward

45. physics

In the figure the man hanging upside down is holding a partner who weighs 535 N. Assume that the partner moves on a circle that has a radius of 6.50 m. At a swinging speed of 3.75 m/s, what force must the man apply to his partner in the straight-down

46. math

a plumber has 12 1/2 feet of plastic pipe he uses 3 2/8 feet for the sink line and 5 3/4 feet for the washing machine . he needs approximately 3 1/2 feet for a disposal. does he have enough pipe left for a disposal?

47. Chemistry

Calculate the ph of a buffer made from 0.25 m NH4Cl and 0.42 M NH3. Kb= 1.8 x 10^-5

48. chemistry

to what volume should you dilute 0.100L of a 15M NaOH solution to obtain a 1.0M NaOH solution

49. math

Joe and Sam went to a canoe rental store. the sign read "canoe rentals: \$10 canoe insurance fee plus \$15 per hour". Joe and Sam wanted to know how much it would cost for them to rent the canoe for different numbers of hours, so they made a table and

50. Social Studies

It can be said that one of the greatest contributions of the Moors was religious tolerance. Do you believe that is true? If so, why is it then that some people view Muslim culture to be a culture of intolerance?

51. Business Communications - English 101

In this paragraph, any errors on capitalization, commas or semicolons? Also, should "they are all to report directly to me be part of the next sentence instead of the first sentence? Thanks again! Howard Clark will be the supervisor for the third shift,

52. chemistry

1. calculate the volume of concentrated HNO_3 (68%)that is needed to prepare stock solution 0.25M in 1000mL volumetric flask. (density HNO_3 = 1.513 g/cm^3) 2. from above stock solution, determine volume needed to dilute to 500mL volumetric flask that

53. ETH/125

2.Sociologists point out that gender differences are maintained through a. systematic socialization. b. the legal system. c. the class system. d. biological differences. i am torn between a & d

54. Bio

1. An isotope is an atom of an element that varies in mass number due to variation in the number of: A. atoms. B. protons. C. neutrons. D. electrons. is it C 2, A covalent bond is: A. the attraction that one atom has for another atom. B. the attraction

55. Com200

One reason language is so powerful is that it is the means by which you construct your reality. T or F I believe the answer is true.

56. Physics

A 17000 kg railroad car travels along on a level frictionless track with a constant speed of 23.0 m/s. A 5100 kg additional load is dropped onto the car. What then will be its speed in meters/second?

57. math

a group of hikers begin their expedition at the grand canyon at an elevation of 56 feet below sea level at 5:00 am .if they climb 14 vertical feet up each hour until 10:00 am ,what is their new elevation ?

58. Geometry, Help

Compare and Contrast Describe the difference between saying that two segments are congruent and saying that two segments have equal length. When would you use each phrase?

59. Geography

which layers of the earth move? Why do ther move?

60. SCIENCE,PHYSICS

According to the legend, Zeus, the king of ancient Greek gods, had the power to create thunderbolts in his hands and throw them at his opponents. Suppose Zeus creates the thunderbolts by bringing his palms very close together and parallel to each other and

61. English; Help/Check.

Leprechauns and Fairy's; Leprechauns are fairy-like mischievous creatures in Irish folklore. They are in a form of a old man. Leprechauns have been reported to be no bigger then a small child or no bigger then a finger. If they are spotted by human they

62. Maths

When the angle of elevation of the sin55 a tower cast a shadow 20m long. Find the height of the tower

63. math

(3/2)(1/3+ 1) (2+7/4)(7/4)(7/4) ---> / that stands for a fraction

64. Math

Find the probability that a number chosen at random between 1 and 100 is divisible by 2 and 7.

65. Physics

You’ve purchased two identical violin strings. You install one of the strings in a conventional violin; the other string you stretch between two posts, each attached to rigid concrete pillar in the open air. Both strings are made of the same materials,

66. science

The greatest height to which a man can throw a stone is H.what will be the greatest distance upto which he can throw the stone?

67. algebra1 HELP PLEASE Thanks you!!

Find the relative minimum of y = 3x^3 + 14x^2 - 10x - 43 Round your answers to the nearest hundredth.

68. history

Akber became emperor at only thirteen years of age. Research his reign. What were his greatest achievements as emperor?

69. math

For every positive integer n, consider all monic polynomials f(x) with integer coefficients, such that for some real number a x(f(x+a)−f(x))=nf(x) Find the largest possible number of such polynomials f(x) for a fixed n

70. chemistry

If you have 156g of SO2, how many molecules do you have?

71. physics

In the drawing, the weight of the block on the table is 380 N and that of the hanging block is 175 N. Ignore all frictional effects, and assuming the pulley to be massless. What is the acceleration of the two block?

72. Bio

1. A control group differs from an experimental group: A. in the number of test organisms used. B. by the independent variable. C. in several ways. D. in no way. is it A 2. A theory and a hypothesis are different in that: A. you must have a theory before

73. Data management gr.12

Find the probability that a number chosen at random between 1 and 100 is divisible by 2 and 7.

74. physics

A 33-kg girl is bouncing on a trampoline. During a certain interval after she leaves the surface of the trampoline, her kinetic energy decreases to 195 J from 425 J. How high does she rise during this interval? Neglect air resistance.

75. math

When I worked this problem out I got the answer \$250.80. It was graded wrong. Can you explain what I did wrong. A deposit of \$8,000 at 9.5% for 120 days \$

76. physics

The rate of energy use in a typical house is about 2.0 kW (2.0 × 103 W). If the kinetic energy of a 1400-kg car is equal to the total energy used by the house in 1 min, what is the car’s speed?

77. history

under Franklin Roosevelt's Good Neighbor policy,

78. Calculus

Solve dy/dx for sin(xy)=1+x^3-y^2

79. SCIENCE

why is a hydrogen molecule (H2) more stable than two individual hydrogen atoms?

80. Algebra 2

A gas station is giving away free glasses with 5 different designs. What is the probability of collecting all 5 in 15 visits to the gas station?

81. English

1. It is strange for her to receive fan letters. 2. It is strange of her to receive fan letters. 3. She is strange to receive fan letters. 4. For her to receive fan letters is strange. 5. Fan letters are strange for her to receive. (Which ones are

82. Business Communications - English 101

This is one paragraph in an interoffice memo. Should it be a semicolon instead of two separate sentences? Also, it is an interoffice memo, should company be capitalized? Thanks! Ed, I have made several changes to our staff to help accommodate the

83. heeeeeeelp math3

For every positive integer n consider all polynomials f(x) with integer coefficients, such that for some real number a *x(f(x+a)−f(x))=n*f(x) Find the largest possible number of such polynomials f(x) for a fixed n

84. chemistry

In my experiments I mixed different ratios of CuSO4 and NaS. The ratio in which I had the greatest amount of precipitate was when I mixed 3mL CuSO4 : 3mL NaS. Now my question: What is indicated by the maximum amount of precipitate...? Thanks in advance.

85. algebra1 HELP PLEASE Thanks you!!

Write a polynomial function in standard form with zeros at 6, -4, and 1

86. math

A. In triangle, the second angle measures twice the first, and the third angle measures 5 more than the second. If the sum of the angles' measures is 180^0, find the measure of each angle. b. The price of a pack of gum today is 63 cent. This is 3 cent more

87. math

Trahen is building a fence that is 6 feet high and 18 feet wide to put around his garden. He has two sizes of boards that he can use. One is 2 feet by 6 feet and the other is 4 feet by 6 feet. Trahen can put the boards either horizontally or vertically and

88. math

The squares of a 3×3 grid are filled with non-negative integers such that the sum of each row and the sum of each column is 7. How many different ways can the squares be filled? Details and assumptions The numbers in each grid square does not need to be

89. history

write a short note of 170-180 words on the travelling experiences of 'James Cook'

90. math

The length of a table is 4m longer than the width. The are is 77m^2. Find the dimensions of the table. l=w+4 w=l-4? I'm stuck?

91. Chemistry

The solubility of AgCl (s) is 2.5 x 10^-5 M. calculate the ksp

92. Chemistry

If the solubility of CaF2 (s) in water is 5.0 x 10^-3 M. The solubility will be

93. Chemistry

A couple questions here: 1. How do you expect nitriding to change the properties of iron? a) Nitriding makes iron stronger. b) Nitriding makes iron weaker. c) Nitriding makes iron more electrically conductive. d) Nitriding makes iron less electrically

94. Math

Three times a number is the same as that number subtracted from 12. What is the number? A) -6 B) -2 C) 2 D) 3 E) 4 I don't get what the question is asking Its a little confusing

95. math

When I worked this problem out I got the answer \$250.80. It was graded wrong. Can you explain what I did wrong. A deposit of \$8,000 at 9.5% for 120 days \$

96. Physics

Steps for drawing an acceleration time graph from a velocity time graph and vice versa?l Please give me proper steps

97. math

MS.powell has -\$25 in her checking account after withdrawing money from the atm .How much did Ms.Powell withdraw if she had \$85 in her checking account before she withdraw the money?

98. math

the temperature in the desert can drop as much as 40'f from noon to midnight .At noon on july 31st the temperature in sahara desert is 3'f .If th temperature drps 39'f by midnight , what is the temperature at midnight ?

99. math

15 − 4 + (7 − 5)^2

100. Algebra 2

Palmer and teller go to the local ice cream parlor after work that offers 40 flavors of ice cream. Palmer wants a cone with chocolate mousse on top, cherry truffle in the middle, and double Dutch chocolate on the bottom. Teller wants a dish with

101. Geometry

1.Explain why we use the formula AB = |a - b| to find the distance of a segment. Include why you need to subtract and why you need to take the absolute value. The formula for finding vector AB is AB = b - a where a and b are the position vectors OA and OB

102. eth/125

Sociologists point out that gender diffrences are maintained through a.systematic socialization b.the legal system c.the class system d. All of these

103. heeeeeelp math

A subset S of {1,2,…,n} is said to be packed if whenever i,j∈S the number ⌊(i+j)/2⌋ is also in S. Determine how many subsets of {1,2,…,25} are packed. Details and assumptions i and j need not be distinct. If i=j is in the set, then clearly so is

104. heeelp math2

Find the number of polynomials f(x) that satisfy all of the following conditions: f(x) is a monic polynomial, f(x) has degree 1000, f(x) has integer coefficients, f(x) divides f(2x^3+x)

105. College 103 Chem

How many grams of Sodium Phosphate would you need to make 225ml of 8.00M of stock solution? Thank you

106. heeeeeeeeelp math

A subset S of {1,2,…,n} is said to be packed if whenever i,j∈S the number ⌊(i+j)/2⌋ is also in S. Determine how many subsets of {1,2,…,25} are packed. Details and assumptions i and j need not be distinct. If i=j is in the set, then clearly so is

107. Math

A basketball team won 10 of its first 20 games. If then won its next 5 games. What fractional part of its total number of games did it win?

108. science

explain the comment ''your brain makes you, you''

109. math

How many integers from 1 to 1000 (exclusive) are divisible by the cube of an integer larger than or equal to 2?

110. SCIENCE,PHYSICS

Exact solutions for many-body problems are rarely encountered in physics. The following problem deals with a non-trivial motion of four charges. Due to the symmetry of the problem it is possible to determine the trajectories of the charges analytically.

111. SCIENCE,PHYSICS

A boy is spinning on a chair and holding a paper bag so that it is horizontal, and perpendicular to the axis of the rotation. What should be the angular velocity of the boy in radians/second so that the bottom of the bag breaks? Details and assumptions

112. SCIENCE,PHYSICS

A helium ion is at rest in a laboratory when it is put in an electric field of E=2 N/C. An infrared light, of wavelength 2000 nm, is directed towards the ion. The ion is moving towards the source of radiation. After what time in the laboratory frame in

113. English

How are leprecuans different or similar to the fairies in A Midsummer Night's Dream?

114. science

two bulb are marked 60 w,220v and 100w,220v.which one of the two will glow brighter?

115. Bio

1. Pseudoscience and nonscience differ in that: A. nonscience is not valuable and pseudoscience is valuable. B. pseudoscience deceives, misleads, or misinforms and this is not a primary characteristic of nonscience. C. nonscience forms hypotheses and

116. Chemistry

A buffer is made from 0.20 M sodium acetate and 0.20 acetic acid. Ka=1.8 x 10^-5. The ph is

117. Economics

According to the U.S. Constitution and judicial review, each person's individual rights guaranteed by the 1st Amendment are absolute, meaning that there are no limits to your rights. True Or False

118. finance in healthcare

Where can I find some information about this? Most of the class is talking about the costs of health care I would like to do something different. I need to find two current health care financial problems and how they overcame the problems and how effective

119. Biology

Which is NOT a major function of proteins? A. Provides cell structure B. Stores energy for the cell C. Functions as regulator molecules in cellular activity D. Functions as carrier molecules is it D

120. alg 1

6(4) ÷ 2 − 1 + 5 I don't understand how to do it step by step

121. Algebra 2

3|x-6| >= -2 Is this correct? x>=16/3 x

122. alg 1

2x − 2y − 5z + 2x + 2y + 3z

123. SCIENCE

why is a hydrogen molecule (H2) more stable than two individual hydrogen atoms?

124. alg 1

−3(d − 3) + 5d

−(6p + 12

5x-10/5 ?

127. Physics

For each of the following scenarios, indicate whether the oscillation period of the pendulum becomes shorter, longer or remains unchanged. Note: you must clearly mark your answer (for example, highlight it in red) from the multiple-choice list below and

128. Calculus

The number of online buyers in Western Europe is expected to grow steadily in the coming years. The function below for 1 t 9, gives the estimated buyers as a percent of the total population, where t is measured in years, with t = 1 corresponding to 2001.