# Tiffany

Most popular questions and responses by Tiffany
1. ## Physics

A cheetah can run approximately 100 km/hr and a gazelle at 80.0 km/hr. If both animals are running at full speed, with the gazelle 70.0 m ahead, how long before the cheetah catches its prey?

2. ## General Chemistry

The problem is: Calculate the standard free-energy change for the following reaction at 25 degrees Celsius. 2Au^+3(aq) + 3Cr(s)-> 2Au(s) + 3Cr^+2(aq) I worked it out, getting half reaction: Au^3+ + 3e- -> Au; E = 1.498 Cr^3+ + 3e- -> Cr; E = -0.74 Ecell =

3. ## Chemistry

Write and balance equation for the complete combustion of decane, C10H22

4. ## Beowulf question

Why was it harder for Beowulf to kill Grendel's mother than Grendel himself?

5. ## Social Studies

Why did the Pilgrims' government come about and why was its existence important. I know this has to do with the Mayflower Compact and was a formal method to establish systematic order among the Pilgrims but not sure why it came about and the importance.

6. ## Math

At the amusement park, you decide to ride the Ferris wheel, which has a maximum height of 50 meters and a diameter of 35 meters. It takes the wheel 5 minutes to make one revolution. If you start your ride at the midline and the ferris wheel rotates counter

7. ## physics

A pitcher throws a 0.5kg ball of clay at a 6kg block of wood. The clay sticks to the wood on impact and their joint velocity afterwards is 3m/s. What is the original speed of the clay? I know the answer is 39m/s but I have no idea how they come up with

8. ## Chemistry

Silver chloride, often used in silver plating, contains 75.27% Ag. Calculate the mass of silver chloride required to plate 195mg of pure silver.

9. ## Chemistry

if an excess of Al and 7.9 mol of Br2 are reacted in equation 2Al + 3Br2= 2AlBr2, how many moles of AlBr2 will be formed assuming a 100% yield

10. ## Chemistry!!!

Is the molarity of a solution that contains 6 moles of solute in 2 liters of solution 12 M????

11. ## Chemistry

A student placed 17.0 g of glucose (C_6H_{12}O_6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100 mL mark on the neck of the flask was reached. The flask was then shaken

12. ## Chemistry

A compound containing only C, H, and O was extracted from the bark of the sassafras tree. The combustion of 36.3mg produced 98.6 of CO2 and 20.2mg of H2O. The molar mass of the compound was 162 g/mol. Determine its empirical and molecular formulas

13. ## ALGEBRA

A transformer has cooling fans that are set to come on when the temperature reaches 32° Celsius. The temperature is 90° Fahrenheit. Are the fans running?

14. ## physics!

A 1.60-kg bottle of vintage wine is lying horizontally in a rack. The two surfaces on which the bottle rests are 90.0° apart, and the right surface makes an angle of 45.0° with respect to the horizontal. Each surface exerts a force on the bottle that is

15. ## Chemistry (College) URGENT

1.6g of an unknown monoprotic acid (HA) required 5.79 mL of a 0.35 M NaOH solution to reach the equivalence point. Determine the molar mass of the acid and given that the pH at the half way point to the equivalent point is 3.86. Calculate the Ka of the

16. ## Chemistry

A mass of 0.4113 g of an unknown acid, HA, is titrated with NaOH. If the acid reacts with 28.10 mL of 0.1055 M NaOH, what is the molar mass of the acid?

17. ## chem 2

calculate kc for reaction I2 (g)+Cl2 (g)⇌2ICl(g )Kp=81.9 (at 298 K)

18. ## calculus

Which of the following are antiderivatives of f(x)=sinxcosx? I f(x)=(sin^2* x)/2 II f(x)=(cos^2* x)/2 III f(x)=-cos(2x)/4

19. ## Chemistry

Determine the number of moles of oxygen atoms in each of the following. 5.91mol H2O2 2.7mol N2O 2.23mol CO2

20. ## Chemistry

If 0.150 moles of salicylic acid and execs acetic anhydride are used during a synthesis of aspirin, how many grams of aspirin will be obtained if the reaction gives a 38% yield?

21. ## Physics

Josh starts his sled at the top of a 3.0m high hill that has a constant slope of 25 degrees. After reaching the bottom, he slides across a horizontal patch of snow. The hill is frictionless but the coefficient of kinetic friction between his sled and the

22. ## computers

Wendy calls the help desk and reports that she is unable to access her files that are stored on the server. The network is a Windows Domain with Active Directory. Wendy is logged on locally to her workstation that runs Windows 8. You remote into her

23. ## algebra 2

what is the answer to algebra with pizzazz page 100; what should you say if you see a tall, wrought-iron tower in paris, france? there are 24 blanks

24. ## 2008 math

Write the following as a sum using powers of 10 to show place value and explain your steps. 3) 620.83

25. ## Chemistry

The problem is: Calculate the standard free-energy change for the following reaction at 25 degrees Celsius. 2Au^+3(aq) + 3Cr(s)-> 2Au(s) + 3Cr^+2(aq) I worked it out, getting half reaction: Au^3+ + 3e- -> Au; E = 1.498 Cr^3+ + 3e- -> Cr; E = -0.74 Ecell =

26. ## PHYSICS!!

Air rushing over the wings of high-performance race cars generates unwanted horizontal air resistance but also causes a vertical downforce, which helps cars hug the track more securely. The coefficient of static friction between the track and the tires of

27. ## Math 75

if you paid \$120 to a loan company for the use of \$2000 for 90 days, what annual rate of interest did they charge?

28. ## Writing

Expository writing prompt: Describe a family celebration that has special meaning for you. Please give me some feedback. Every year my uncle celebrates Christmas at his house. Unlike the common Christmas party where people hand out presents to other

29. ## Social Studies

South Africa gained its independence from Britain in 1910. Why did this not lead to freedom and equality in South Africa?

30. ## college algebra

The​ half-life of​ carbon-14 is 5600 years. If a piece of charcoal made from the wood of a tree shows only 73​% of the​ carbon-14 expected in living​ matter, when did the tree​ die?

31. ## statistics

David wants to rent an unfurnished apartment for next semester. He took a random sample of 9 apartments adversised in the local Halifax paper, and recorded the rental rates. The rents (in \$ per month) were: 500 650 600 505 450 550 515 495 640 a) Find a 90%

32. ## Urgent-Chemistry Help

I need help with the heat effects and calorimetry worksheet. Please explain how to solve it! Thank you so much! A metal sample weighing 45.2g and at a temperature of 100.0 C was placed in 38.6g of water in a calorimeter at 25.6 C. At equilibrium the

33. ## Math

Tommy has 5 jars. Each jar is 2/3 filled with marbles. How many full jars of marbles does tommy have ?

34. ## Chemistry

Give the formula of each of the following copper minerals: A. cuprite, copper (I) oxide B. chalcocite, copper (I) sulfide C. covellite, copper (II) sulfide

35. ## Calculus

Find the area of the indicated region. We suggest you graph the curves to check whether one is above the other or whether they cross, and that you use technology to check your answer. Enclosed by y = x^2 − 4x + 1 and y = −x^2 + 4x − 5

36. ## General Education

Memmie: The greater the population near a restaurant, the more potential customers it has and the greater chance its popularity will spread through word-of-mouth. O’Sullivans Restaurant just opened in the very densely populated town of Redville, so its

37. ## Chemistry

NH4+ + OH- NH3 + H2O What is the K for the reaction above in terms of Ka's, Kb's, Kw etc.?

38. ## Chemistry

Find the volume of 0.250M sulfuric acid necessary to react completely with 79.3g sodium hydroxide

39. ## General Education

Only circus animals with a clean bill of health will perform in today’s exhibition. A monkey, a poodle, and a horse will perform in today’s exhibition. No circus animals with a clean bill of health were prescribed medications this week. If the

40. ## General Education

Aron: The two double A batteries in my CD player are dead, so the CD player doesn’t work. My television remote control, which also uses two double A batteries, works fine. So if I move the two batteries from my television remote control to my CD player,

41. ## Practical English

What is the topic sentence in this paragraph? (1)A trip to the ocean can be a relaxing escape from the everyday pressure of life. (2)A sailboat glistening on the horizon provides a mental escape to faraway places. (3)the rhythm of the ocean beating against

42. ## Physics

A record player rotates a record at 45 revolutions per minute. When the record player is switched off, it makes 5 complete turns at a constant angular acceleration before coming to rest. What was the magnitude of the angular acceleration (in rads/s2) of

43. ## Chemistry

An antacid contains 200mg of aluminum hydroxide and 200mg of magnesium hydroxide per capsule. a. How many moles of Al(OH)3 does each capsule contain? 2.56 x 10^-3 mol Al(OH)3 is that correct? b. What is the mass in milligrams of 0.0457 mole of magnesium

44. ## Physics 202

A rail gun uses electromagnetic forces to accelerate a projectile to very high velocities. The basic mechanism of acceleration is relatively simple and can be illustrated in the following example. A metal rod of mass 10.0g and electrical resistance 0.100Ω

45. ## Chemistry

To increase the solubility of a gas at constant temperature from 1.20 g/L at 1.4 atm to 2.3 g/L what would the pressure have to be increased to?

46. ## Chemistry

How many kilograms of chlorine are in 22 kg of each of the following chlorofluorocarbons CFCs? 1.CF2Cl2 2.CFCl3 3.C2F3Cl3 4.CF3Cl

47. ## Chemistry

Calculate the mass of Fe(OH)3 s) produced by mixing 50.0 mL of 0.153 M KOH (aq) and 25.0 mL of 0.255 M Fe(NO3)3 (aq), and the number of moles of the excess reactant remaining in solution. I got 0.00383 mol Fe(NO3)3 remaining. I don't know how to obtain the

48. ## Chemistry

The uranium used for nuclear fuel exists in nature in several minerals. Calculate how many moles of uranium are in 6.0 moles of the following: Carnotite; K2(UO2)2(VO4)2*3H2O Uranophane; CaU2Si2O11*7H2O Autunite; Ca (UO2)2(PO4)2*10H2O

49. ## Physics

The earth has about 80 times the mass of the earth’s moon. The gravitational force exerted on the moon by the earth has what relation to the gravitational force exerted on the earth by the moon? 1. the same as 2. zero; the earth exerts a force on the

50. ## Chemistry

Fill in the missing information in the following table of four neutral atoms Symbol- 37Cl number of protons- 36 46 number of neutrons- 42 number of electrons- 33 mass number- 77 106

51. ## Grammar (will you check the rest please)

FIND THE ADVERB AND THE WORD IT MODIFIES 1. Mac looked everywhere for his jacket but could not find it.EVERYWHERE MODIFIES LOOKED AND FIND MODIFIES COULD 2. Tom threw the ball fast and hard. FAST, HARD MODIFIES THREW 3. Soon it will be time to go to sleep.

52. ## physics

A ball is thrown straight downward from the surface of the moon. Is the maximum height it reaches less than, equal to, or greater than the maximum height reached by a ball thrown upwards on the earth with the same initial speed? Ignore air resistance in

53. ## math

Noah wants to display his 72 collectors flags.he is going to put 6 flags in each row.how many rows of flags will he have in his display?

54. ## chem

Determination of the solubility product of PbI2. From the experimental data we obtain [I-] directly. To obtain Ksp for PbI2, we must calculate [Pb2+] in each equilibrium system. This is most easily done by constructing an equilibrium table. We first find

55. ## chemistry

What volume of 16 M nitric acid must be diluted with distilled water to prepare 500.0 mL of 0.50 M HNO3?

56. ## smith

The Smiths want to buy a 9 ft. by 12 ft. carpet and center it in a 15 ft. by 20 ft. room. What is the area of the carpet?

57. ## intro to computers

You call the help desk to report a problem you are having on your computer. The technician asks you what operating system you are running. You know it is Windows 7 but you forget which version. How can you find out?

Ashton broke apart a number into 30+7. What number did she start with?

59. ## physics

nucleus of oxygen-15 undergoes electron capture. Write out the reaction equation and determine the identity of the daughter nucleus

60. ## statistics

a machine has 0.04 probability of producing a defective item. If it produces 6 items find: a. probability none is defective b. at least one is defective c. all are defective

61. ## calculus

1. A conical reservoir has a depth of 24 feet and a circular top of radius 12 feet. It is being filled so that the depth of water is increasing at a constant rate of 4 feet per hour. Determine the rate in cubic feet per hour at which water is entering the

62. ## PHYSICS

Two horizontal forces, F1 and F2, are acting on a box, but only F1 is shown in the drawing. F2 can point either to the right or to the left. The box moves only along the x axis. There is no friction between the box and the surface. Suppose that = +6.2 N

63. ## Physics

Why are the tires for trucks carrying gasoline and other ﬂammable ﬂuids manufactured to be electrically conducting? 1. To make the truck easier to drive 2. To move the positive charges from the truck to the ground and avoid ﬁre 3. To neutralize the

64. ## Physics help!

An extreme skier, starting from rest, coasts down a mountain that makes an angle of 26.7 ° with the horizontal. The coefficient of kinetic friction between her skis and the snow is 0.248. She coasts for a distance of 10.5 m before coming to the edge of a

65. ## Chemistry II

At a certain temperature, Kc = 33 for the reaction: H2(g) + I2(g) 2HI(g) Assume that the initial concentrations of both H2 and I2 are 6.00 x 10-3 mol/L. Find the concentration of each reactant and product at equilibrium.

66. ## Physics (76)

the weight of the block on the table is 422 N and that of the hanging block is 185 N. Ignoring all frictional effects and assuming the pulley to be massless, find (a) the acceleration of the two blocks and (b) the tension in the cord.

67. ## Physics

A person pushes on a 60-kg refrigerator with a horizontal force of -260 N; the minus sign indicates that the force points in the -x direction. The coefficient of static friction is 0.68. (a) If the refrigerator does not move, what are the magnitude and

68. ## physics

the frequency of middle C on a piano is 261.6hz. What is the wavelength of sound as it travels @room air and in water?

69. ## chemisty

what is the final pH after 1 drop(.05ml) of 6M HCl is added to 1.0L of freshly prepared pure water that was originally at a pH of 7.0. Is there a signigicant pH change?

70. ## Chemistry- Writing Net Ionic equations

I need to write the net inonic equation for (NH4)2SO4(aq) and KNO2(aq). I need to know the reactants and the product. I worked it out and got: 2K+(aq) + SO4-(aq) ----> K(SO4)2(s)

71. ## Chemistry

how many grams of NaCN would you need to dossolve in enough water to make exactly 250.0mL of soultion with pH of 10.00?

72. ## prob. statistics

a survey indicates that 41% of women in the us consider reading as their favorite leisure time activity. you randomly select 4 women and ask them if reading is their favorite leisure time activity. find the probability that exactly 2 of them said yes

73. ## chemistry

how to write this as a net ionic equation? Al(s)+ H2SO4(aq)

74. ## economics

Give two examples of price discrimination. In each case, explain why the monopolist chooses to follow this business strategy.

75. ## Chemistry

Calculate the enthalpy change in kJ when 21.6g of H2S is burned. 2H2S(g) + 3O2(g) --> 2SO2(g) + 2H20(g) Change in H=-1036kJ/mol

76. ## Grammar (will you check the rest please)

FIND THE ADVERBS 1. Pedro enthusiastically supported Zach's bid for student council president. ENTHUSIASTICALLY 2. Spend your money wisely. WISELY 3. Marissa waited quietly for the play to begin. QUIETLY 4. Lightly underline the words you want to

77. ## Macroeconomics

Peter Pundit, an economics reporter, states that the European Union (EU) is increasing its productivity very rapidly in all industries. He claims that this productivity advance is so rapid that output from the EU in these industries will soon exceed that

78. ## 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^-19C.

79. ## spanish

In the following sentences, change the position of the reflexive pronouns so that sentences retain their meaning. Have the correct account punctuation and accentuation. 1. Ellos vienen a despedirse esta noche 2. Daniel se esta afeitando 3. Patricia va a

80. ## math

George finds a company that charges 59 cnets per day for each 1000 borrowed. if he borrows 3000 for 60 days, what amount will he repay, and what annual interest rate will he pay the company?

81. ## Chemistry

What is the frequency of the photons emitted by hydrogen atoms when they undergo transition from n=5 to n=3?

82. ## Chemistry

The specific heat of solid copper is 0.385 J/g*C. What thermal energy change occurs when the temperature of a 40.10g sample of copper is cooled from 42.9C to 10.0C? Be sure to give you answer the proper sign. I know this is part of the answer which

83. ## Brief Calculus

The demand function for a certain make of replacement cartridges for a water purifier is given by the following equation where p is the unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. p = −0.01x2 − 0.3x

84. ## Physics

A freight train has a mass of 1.7 107 kg. If the locomotive can exert a constant pull of 7.6 105 N, how long does it take to increase the speed of the train from rest to 64 km/h?

85. ## Bus.Math

John O'Sullivan has just completed his first year in business. His records show that he spent the following in advertising: Newspaper \$725 Radio \$525 Yellow Pages \$700 Local flyers \$425 What percent of John's advertising was spent on the Yellow Pages?

86. ## physics homework! #92

A small sphere is hung by a string from the ceiling of a van. When the van is stationary, the sphere hangs vertically. However, when the van accelerates, the sphere swings backward so that the string makes an angle of è with respect to the vertical. Find

87. ## Math

On a Science exam Rita answered 36 questions correctly and receive a score of 100% her friend answered 27 questions correctly what score did read her friend receive

88. ## Physics!

One of the new events in the 2002 Winter Olympics was the sport of skeleton (see the photo). Starting at the top of a steep, icy track, a rider jumps onto a sled (known as a skeleton) and proceeds - belly down and head first - to slide down the track. The

89. ## physics! (69)

A damp washcloth is hung over the edge of a table to dry. Thus, part (mass = mon) of the washcloth rests on the table and part (mass = moff) does not. The coefficient of static friction between the table and the washcloth is 0.395. Determine the maximum

90. ## physics

Your groceries are in a bag with paper handles. The handles will tear off if a force greater than 59 N is applied to them. (a) What is the greatest mass of groceries that can be lifted safely with this bag, given that the bag is raised with constant speed?

91. ## Chemistry

heptane and water do not mix, and heptane has a lower density (0.684g/mL) than water (1.00g/mL). A 100mL graduate cylinder with an inside diameter of 3.10 cm contains 39.90g of heptane and 34.00g of water. What is the combined height of the two liquid

92. ## Physics

The ends of a light string are tied to two hooks A and B in a ceiling which are 100 cm apart horizontally so that the length between hooks is 140 cm. A 650g mass is then attached by a second length of string to a point C on the first, 80 cm from A, and

93. ## Chemistry

For a particular isomer of C8H18, the following reaction produces 5104.1 kJ of heat per mole of C8H18(g) consumed, under standard conditions. (deltaH_rnx = -5104.1kJ) What is the standard enthalpy of formation of this isomer of C8H18(g)?

94. ## economics

You are hired as the consultant to a monopolistically competitive firm. The firm reports the following information about its price, marginal cost, and average total cost. Can the firm possibly be maximizing profit? If not, what should it do to increase

Sally has three times as many dimes as nickels and twice as many quarters as dimes.In all she has \$5.55. How many coins of each type does she have? Let 2x=quarters 3x=dimes x=nickles

96. ## chemistry

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 94, and shows prominent peaks in its IR spectrum at 3600–3200 and 1600 cm–1? A) The compound has a molecular mass of 94. B) The

97. ## phsyics

The block shown in figure below lies on a smooth plane tilted at an angle è = 21.5° to the horizontal. Determine the acceleration of the block as it slides down the plane. Ignore friction.

98. ## chemistry

Imagine that you have a 7.00 gas tank and a 3.50 gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 115 , to what pressure