# Questions Asked in December 2010

## Most Popular Questions of December 2010

1. ### Chemisty.....Help =))

What is the molarity of ZnCl2 that forms when 30.0g of zinc completely reacts with CuCl2 according to the following reaction? Assume a final volume of 285 mL . (please explain step by step I have no clue!) Zn(s) + CuCl2(aq) --> ZnCl2(aq)+ Cu(s)

asked by Lisa, Help needed! on December 7, 2010
2. ### Calculus

If the volume of a cube is increasing at 24 in^3/min and the surface area of the cube is increasing at 12 in^2/min, what is the length of each edge of the cube? I know that dV/dt=24 and ds/ds=12. I also know that Volume=s^3 and Surface Area=6*s^2, but what

asked by Anna on December 7, 2010
3. ### physics

a light string 4 meters long is wrapped around a solid cylindrical spool with a radius of 0.075 m and a mass of .5 kg.a 5kg mass is then attached to the end of the string, causing the string to unwind from the spool. a. what is the angular acceleration of

asked by mariel on December 3, 2010
4. ### Physics

A 0.075 kg ball in a kinetic sculpture moves at a constant speed along a motorized conveyor belt. The ball rises 1.32 m above the ground. A constant frictional force of 0.350 N acts in the direction opposite the conveyor belt's motion. What is the net work

asked by Brian on December 9, 2010
5. ### chemistry HELP!

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution: a solution that is 0.170 M in HC2H3O2 and 0.105 M in KC2H3O2

asked by Lisa on December 15, 2010
6. ### US History

how was the establishment of the cabinet the most significant event in George Washington's presidency?

asked by Anonymous on December 19, 2010
7. ### COM155

Use at least five adverbs and five adjectives to write a brief review of a movie, sporting event, musical performance, or television show. • Bold each adverb. • Underline each adjective. • Compare the event to one or more similar events. When

asked by Glenda on December 17, 2010
8. ### Physics

The front 1.20 m of a 1550 kg car is designed as a "crumple zone" that collapses to absorb the shock of a collision. (a) If a car traveling 26.0 m/s stops uniformly in 1.20 m, how long does the collision last? cannot_evaluate s (b) What is the magnitude of

asked by Brittany on December 9, 2010
9. ### math

1. You are debating about whether to buy a new computer for \$800.00 or a refurbished computer with the same equipment for \$640.00. If a savings account earns 4.5% APR interest, how much do you really save with a refurbished computer if you put the

asked by Donnie on December 1, 2010
10. ### Chemistry

The normal boiling point of ethanol is 78.4°C. When 9.16 g of a soluble nonelectrolyte was dissolved in 100. g of ethanol, the vapor pressure of the solution at that temperature was 7.40 102 Torr. (a) What are the mole fractions of ethanol and solute? (b)

asked by Daiyo on December 10, 2010
11. ### chemistry

2. A 350 mL buffer solution containing 0.15 M HF and 0.150 M NaF is reacted with sodium hydroxide. What mass of NaOH can this buffer neutralize before the pH rises above 4.0? If the same volume of buffer was 0.35 M in HF and 0.35 M in NaF then what mass of

asked by help on December 1, 2010
12. ### Physics

When four people with a combined mass of 320 kg sit down in a car, they find that the car drops 0.80 cm lower on its springs. Then they get out of the car and bounce it up and down. What is the frequency of the car's vibration if its mass (when it is

asked by Y0gi on December 7, 2010
13. ### physics

The length of a simple pendulum is 0.79m and the mass of the particle at the end of the cable is 0.24 kg. The pendulum is pulled away from its equilibrium position by an angle of 8.5 degrees and released from rest. Assume that friction can be neglected and

asked by David on December 12, 2010
14. ### statistics

The red face cards and the black cards numbered 2-9 are put into a bag. Four cards are drawn at random without replacement. Find the following probabilities: a) All 4 cards are red b) 2 cards are red and two cards are black c) At least one of the red cards

asked by oscar on December 12, 2010
15. ### chemistry

lithium + gold(III) chloride +lithium chloride + gold need to balance equation

asked by jin on December 5, 2010
16. ### Physics

A 4.00-m-long, 500 kg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 70.0 kg construction worker stands at the far end of the beam. What is the magnitude of the torque about

asked by Anonymous on December 4, 2010
17. ### algebra

what did the beaver say to the tree? using only these letters egatkwolifunydcsmb. you may use these letters more than once

asked by matt on December 14, 2010
18. ### Chemistry

Given the balanced equation representing a reaction: Cao(s) + CO2(g) ---> CaCO3(s) + heat What is the total mass of CaO(s) that reacts completely with 88 grams of CO2(g) to produce 200. grams of CaCO3(s)? I don't understand what you have to do.

asked by danny123 on December 18, 2010
19. ### social studies

what ar all the anwsers to florida studies weekly on week 13

asked by daniel on December 1, 2010
20. ### chemistry

a student needs to prepare an aqueous solution of sucrose at a temperature of 20 degrees c with a vapor pressure of 15. 0 mm Hg. How many grams of sucrose (mm=342 g/mol) does she need if she uses 375 g H20? (the vapor pressure of water at 20 degrees c is

asked by meghan on December 2, 2010
21. ### Physics

A 4-kg sled sliding freely on an icy surface experiences a 2 _ N frictional force exerted by the ice and an air-resistive force of 0.5 N. a. What is the net force acting on the sled? b. What is the acceleration of the sled?

asked by Katherine on December 28, 2010
22. ### Physics

At a rock concert, the sound intensity 1.0 in front of the bank of loudspeakers is 0.10 . A fan is 30 from the loudspeakers. Her eardrums have a diameter of 8.4 .How much energy is transferred to each eardrum in one second?

asked by Ness on December 13, 2010
23. ### chemistry

Will sodium sulfide and iron II sulfate form a precipitate? if so what would the reaction look like?

asked by kelly on December 12, 2010
24. ### college

You buy an eight year bond that has a 6% current yield and a 6% coupon (paid annually). In one year, promised yields to maturity have risen to 7%. What is your holding period return?

asked by Anonymous on December 3, 2010
25. ### honors physics

A 3.2 kg block is hanging stationary from the end of a vertical spring that is attached to the ceiling. The elastic potential energy of this spring/mass sytem is 2.1 J. What is the elastic potential energy of the system when the 3.2 kg block is replaced by

asked by tom on December 1, 2010
26. ### chemistry! URGENT!!!

A gaseous mixture of O2 and N2 contains 30.8 % nitrogen by mass. What is the partial pressure of oxygen in the mixture if the total pressure is 365 mmHg?

asked by chelsey on December 6, 2010
27. ### physics

A student pulls a 60.-newton sled with a force having a magnitude of 20. newtons. What is the magnitude of the force that the sled exerts on the student

28. ### differentiability

If g is a differentiable function such that g(x) is less than 0 for all real numbers x and if f prime of x equals (x2-4)*g(x), which of the following is true? A. f has a relative maximum at x=-2 and a relative minimum at x=2, B. f has a relative minimum at

asked by matthew on December 31, 2010
29. ### physics

Four identical masses of 2.7 kg each are located at the corners of a square with 1.4 m sides. What is the net force on any one of the masses? F=((G)(m1)(m2))/r^2 I don't understand why im not getting it right... i need help please!!

asked by lissa on December 19, 2010
30. ### Calculus

If f(x)= sqrt(4sin(x)+2), then f'(0)=

asked by Anna on December 8, 2010
31. ### Chemistry

OK I just need help with two final problems that I am stuck on: The problem states the calcium carbonate in limestone reacts with HCl to produce a calcium chloride solution and carbon dioxide gas CaCO3(s)+2HCl(aq)-->CaCl2(aq)+H2O(l)+CO2(g) 1)Find how many

asked by TT on December 9, 2010
32. ### Grade 11 math - HELP!

Skyscrapers sway in high-wind conditions. in one case, at t=2s, the top floor swayed 30cm to the left (-30cm), and at t=12, the top floor swayed 30 cm to the right (+30cm) of its starting position. a) what is the equation of a sinusoidal function that

asked by Allison on December 21, 2010
33. ### Physics

A cube of solid aluminum has a volume of 1.00 m^3 at 20 degree C. What temperature change is required to produce a 100-cm^3 increase in the volume of the cube? I know you are supposed to use: DeltaV=Beta*Vo*DeltaT. But I don't know what Beta is and the

asked by HELP on December 12, 2010
34. ### calculus

the side of a cube is expanding at a constant rate of 2 centimeters per sesond. what is the instantaneous rate of change of the surface area of the cube, in cm2 per second, when its volume is 27 cubic cm

asked by Felicia on December 30, 2010
35. ### Physics HELP!

A 650 N boy and a 490 N girl sit on a 150 N porch swing that is 1.70 m long. If the swing is supported by a chain at each end, what is the tension in each chain when the boy sits .75 m from one end and the girl .5 m from the other end?

asked by Jennifer on December 5, 2010
36. ### math

The 2 pulleys in the figure have radii of 15 cm and 8 cm, respectively. The larger pulley rotates 25 times in 36 seconds find the angular velocity of each pulley in radians per second. Find angular velocity of each pulley in radians per second.

asked by confused on December 2, 2010
37. ### Chemistry

The solubility of CO2 in water at 25 degrees C and 1 atm is 0.034 mol/L. What is its solubility under atmospheric conditions? (The partial pressure of CO2 in air is 0.0003 atm.) Assume that CO2 obeys Henry's law. My Answer: 1.02 x 10^-5 mol/L

asked by Sara on December 2, 2010
38. ### Chemistry

Calculate the molarity and the molality of an NH3 solution made up of 30 g of NH3 in 70 g of water. The density of the solution is 0.982 g/ml. Molar Mass of NH3 = 17.04 g

asked by Sara on December 2, 2010
39. ### chemistry Molarity

You have 353 mL of a 1.25 M potassium Chloride solution, but you need to make a 0.50 M potassium Chloride solution. How many milliliters of water must you add to the original 1.25 M solution to make the 0.50 M potassium Chloride solution

asked by Kevin on December 11, 2010
40. ### Calculus

A particle is moving around the unit circle (the circle of radius 1 centered at the origin). At the point (.6 , .8), the particle has horizontal velocity dx/dt=3. What is its vertical velocity dy/dt at that point? I don't know what equation to use or

asked by Anna on December 7, 2010
41. ### chemistry........help!! =)

One brand of laundry bleach is an aqueous solution containing 4.00% sodium hypochlorite (NaOCl) by mass What is the molarity of this solution? (Assume a density of 1.02 g/mL .)

asked by Lisa, Help needed! on December 8, 2010
42. ### Chemistry (URGENT)

In order to analyze the waste water containing Co^2+ from a manufacturing process, 1.0L of water was evaporated to 10.0mL, then placed in a spectrophotometer tube. The absorbance was found to be 0.20. Using your calibration curve, calculate the number of

asked by John on December 16, 2010
43. ### math

how to find the four geometric means between 5 and 1215

asked by g on December 9, 2010
44. ### Phyiosics

Three point charges lie in a straight line along the y-axis. A charge of q1 = -9.50 µC is at y = 6.30 m, and a charge of q2 = -7.20 µC is at y = -4.00 m. The net electric force on the third point charge is zero. Where is this charge located? y = m

asked by Ed on December 19, 2010
45. ### calculus

Two positive numbers have a sum of 60. what is the maximum product of one number times the square of the second number? a) 3481 b) 3600 c) 27,000 d) 32,000 e) 36,000 So Idk if this is right, but I have .... x+y=60 p=xy^2 p=x(60-x)^2 P'=-2x(60-x)+(60-x^2)

asked by Jenny on December 14, 2010
46. ### Math

The diameter of a car's tire is 52 cm. While the car is being driven, the tire picks up a nail. How high above the ground will the nail be after the car has travelled 0.1 km? It also asked me to graph this information. So I created a periodic graph that

asked by Allison on December 12, 2010
47. ### Chemistry

A sample of gas confined in a cylinder with a movable piston is kept at constant pressure. The volume of the gas doubles when the temperature of the gas is changed from a. 200. K to 400. K b. 200. C to 400. C How do you know if it's kelvin or celsius? k= c

asked by danny123 on December 4, 2010
48. ### Trig

How do you convert rectangular equations into polar equations? If x4−y4=xy , then r2=atan(b); What is a? What is b?

asked by Audrey on December 13, 2010
49. ### Chemistry

Which of the following compounds has the highest vapor pressure at 25°C? A. CH3CH2OH B. CH3OCH3 C. CH3CH2CH2Cl D. CH3CH2CH3 E. CH3CH2CH2CH

asked by Jake on December 9, 2010
50. ### Statistics

A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 12 hours, with a standard deviation of 3 hours. It is desired to estimate the mean viewing time

asked by Shyra on December 2, 2010
51. ### Math

While standing at the left corner of the schoolyard in front of her school, Suzie estimates that the front face is 8.9 m wide, and 4.7 m high. From her position, Suzie is 12.0 m from the base of the right exterior wall. She determines that the left and

asked by Taylor on December 3, 2010
52. ### geometry

find the area of a regular hexagon with the side length 4m. round to the nearest tenth

asked by john on December 9, 2010
53. ### AP Calculus

A rectangle is inscribed between the parabolas y=4x^2 and y=30-x^2. what is the maximum area of such a rectangle? a)20root2 b)40 c)30root2 d)50 e)40root2

asked by Jim on December 14, 2010
54. ### geometry

The perimeter of an isosceles triangle is 42 cm . its base is 2/3 times the sum of the equal sides . find the length of each side and the area of the triangle.

asked by saurav kumar on December 30, 2010
55. ### Chemistry Help

What is the ionic equation for: 2 HClO4(aq) + Mg(OH)2(s) ¨ Mg(ClO4)2(aq) + 2 H2O(l)

asked by Sarah on December 18, 2010
56. ### english

at the end of chapter IV, Frankenstein pauses to moralize. What does he say about passion and how a person should deal with it?

asked by amanda on December 1, 2010
57. ### physics

20 kg , 30 cm diameter disk is spinning at 300 rpm. How much friction force must be applied to rim to bring the disk to a halt in 3.0s?

asked by Justin on December 15, 2010
58. ### college

what is the mass of solute dissolved in 50.0g of a 12.5% saline solution?

asked by debbie on December 16, 2010
59. ### Physics

A 1125 kg car carrying four 80 kg people travels over a rough "washboard" dirt road with corrugations 4.0 m apart which causes the car to bounce on its spring suspension. The car bounces with maximum amplitude when its speed is 17 km/h. The car now stops,

asked by Robert on December 13, 2010
60. ### AP calculus AB

A spy tracks a rocket through a telescope to determine its velocity. The rocket is traveling vertically from a launching pad located 10 km away. At a certain moment, the spy's instruments show that the angle between the telescope and the ground is equal to

asked by jennifer on December 29, 2010
61. ### Chemistry

a chemist needs to order Na2B4O7. One supplier offers it in an anhydrous (without water) form, while another offers it as a hydrated crystal, Na2B4O7*10H20. if the prices from the two suppliers are the same for a 500.0-g bottle, which one would supply more

asked by Anonymous on December 15, 2010
62. ### Chemistry

WHAT IS THE BOILING POINT OF THIS SOLUTION? 1.00x10^2g C10,H8,O6,S2 (1,5-naphthalenedisulfonic acid) in 1.00x10^2g H2O (nonionizing solute)

asked by Jose Reyes on December 7, 2010
63. ### College Physics w/Calculus

(a) What is the escape speed on a spherical asteroid whose radius is 570 km and whose gravitational acceleration at the surface is 3.1 m/s2? (b) How far from the surface will a particle go if it leaves the asteroid's surface with a radial speed of 1000

asked by Oriana on December 14, 2010
64. ### physics

racing on a flat track, a car going 32 m/s rounds a curve 56m in radius. what is the car's centripetal acceleration?

asked by john on December 1, 2010
65. ### Chemistry

the bond between which pair of elements is the least ionic in character ? (1) H-F (2)H-Cl (3) H-I (4) H-O please help

asked by Anonymous on December 1, 2010
66. ### Chemistry

Palladium-107 undergoes â decay (t1/2 = 6.5 x 105 yr) to form silver-107. How long will it take for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107? help please...thank you :)

asked by Queen on December 7, 2010
67. ### trig

simplify cos(30+x)+cos(30-x)

asked by Anonymous on December 11, 2010
68. ### chem. 7

a 20% solution of H2SO4 has a density of 1.14 g/mL. calculate the molarity, normality and molality of the solution.

asked by Anonymous on December 3, 2010
69. ### physics

1.) A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed 2.5 cm in bringing

asked by David on December 13, 2010
70. ### calculus

The strength of a rectangular beam is proportional to width*depth^2. What are the dimensions of the strongest rectangular beam that can be cut out of a 12 inch diameter log?

asked by Susan on December 4, 2010
71. ### Chemistry

What is the molarity of the resulting solution when 300. mL of a 0.400 M solution is diluted to 800. mL?

asked by Ivy on December 6, 2010
72. ### AP Chemistry

Two solid objects, A and B, are placed in boiling water and allowed to come to temperature there. Each is then lifted out and placed in separate beakers containing 1000 g water at 10.0 degrees Celsius. Object A increases the water temperature by 3.50

asked by Samantha on December 2, 2010
73. ### Chemistry

A 22.5 gram sample of ammonium carbonate contains ? mol of ammonium ions?

asked by Gina on December 8, 2010
74. ### history

For what purpose Muslim League branch in London was established? ► To organize the Muslim community in London ► To draw attention to the misinterpretation and plans of the Hindus against the Muslims ► To emphasize the conspiracies of the British

asked by pinki on December 10, 2010
75. ### physics

In designing rotating space stations to provide for artificial-gravity environments, one of the constraints that must be considered is motion sickness. Studies have shown that the negative effects of motion sickness begin to appear when the rotational

asked by jessica on December 19, 2010
76. ### sociology

If appointed to head the U.S. Civil Service Commission, what polices would you propose to reduce radical ethnic strife in the U.S. and why?

asked by lakesha on December 3, 2010
77. ### Physics

A 55 kg skier is at the top of a slope that is 10.0 m high. a) Set the zero level for gravitational potential energy at the bottom of the slope and find the gravitational potential energy for the skier at the top and the bottom of the slope. What is the PE

asked by Daniel Reinsnes on December 2, 2010
78. ### chem

Consider the following unbalanced equation: C2H5OH(g) + O2(g) → CO2(g) + H2O(l) 1.55 g of ethanol reacts with 10.0 g of oxygen. What is the total volume of gas present (in L) after the reaction is complete, assuming the reaction takes place at 1.00 atm

asked by Bogdanam on December 15, 2010
79. ### Chemistry

Diethyl ether has a boiling point of 34.5C, and 1-butanol has a boiling point of 117C. Both of these compounds have the same numbers and types of atoms. Explain the difference in their boiling points. The answer I found was that: only 1-butanol can form

asked by Sara on December 6, 2010
80. ### Chemistry

What is the solubility equilibrium for Mn3(PO4)2? Isn't it this.. Mn3(PO4)2 (s) --> 3Mn^+2 (aq) + 2PO4^-3 (aq) but i keep getting it wrong. suggestions?

asked by Savannah S. on December 5, 2010
81. ### Chemistry

Please show me the steps..... At STP, 3.00 L of nitrogen gas contains the same number of molecules as A) 1.00 L of nitrogen gas B) 2.00 L of oxygen gas C) 3.00 L of chlorine gas D) 4.00 L of hydrogen gas

asked by Kiesha on December 1, 2010
82. ### Chemistry

A rigid cylinder contains a sample of gas at STP. What is the pressure of this gas after the sample is heated to 410 K? a. 1.0 atm b. 0.50 atm c. 0.67 atm d. 1.5 atm Explain how you get the answer.

asked by danny123 on December 12, 2010

Of the sixth-grade students surveyed, 12% bring their lunches to school. Suppose 24 sixth-graders do this? How many sixth-grade are at the school?

asked by Anonymous on December 1, 2010
84. ### Physics

A 0.003 0-kg lead bullet is traveling at a speed of 240 m/s when it embeds in a block of ice at 0°C. If all the heat generated goes into melting ice, what quantity of ice is melted? (Lf = 80 kcal/kg, the specific heat of lead = 0.03 kcal/kg×°C, and 1

asked by Jesse on December 19, 2010
85. ### Chemistry

What is the percent by mass of glucose in a solution containing 0.15 moles of glucose dissolved in 410g acetic acid? The molar mass of glucose is 180g/mol

asked by Lauren smith on December 15, 2010
86. ### physics

Two identical containers are open at the top and are connected at the bottom via a tube of negligible volume and a valve which is closed. Both containers are filled initially to the same height of 1.00 m, one with water, the other with mercury, as the

asked by maria on December 6, 2010
87. ### chemistry

The copper(I) ion forms a chloride salt that has Ksp = 1.2 10-6. Copper(I) also forms a complex ion with Cl ‾. Cu+(aq) + 2 Cl ‾(aq) reverse reaction arrow CuCl2‾(aq) K = 8.7 104 Calculate the solubility of copper(I) chloride in pure water. (Ignore

asked by Anonymous on December 4, 2010
88. ### math 11

i dontget how the textbook got the answer, h = -30cos[(1.43)x]° + 40 the question is: a paintball is shot at a wheel of radius 40 cm. the paintball leaves a cricuarmark 10 cm from the outer edge of the wheel. As the wheel rolls, the mark moves in a

asked by pranav on December 13, 2010

If wind blows at a speed of 30 m/s over the roof of your house, what is the pressure diference on your roof between the air inside and the air outside? What net force does this produce on a roof having an area of 175 m^2? 1.3 kg/m^3 is the density of air.

asked by Katie on December 5, 2010
90. ### chemistry

which solution has the highest concentration of hydroxide ions? a ph=7.93 b ph=12.59 c ph=7.00 d ph=9.82 e ph=3.21 i know the answer is 7 but why is it seven? would it be different if it said hydronium ions?

asked by jessie on December 11, 2010
91. ### Trig

An airplane is flying on a compass heading (bearing) of 340 degrees at 325 mph. A wind is blowing with the bearing 320 degrees at 40 mph. Find the component form of the velocity of the airplane. then find the actual ground speed and direction of the plane

asked by K on December 17, 2010
92. ### Physics

The oven draws 1100W of power, and you have determined that it heats with an efficiency of 51%. Using this information, determine the time t it would take to bring 240mL of water from 25C to 100C . Note that 4.2 J of energy is required to raise the

asked by Mike on December 10, 2010
93. ### Math

maria's bicycle has a diameter of 64 cm. as she rides at the speed of 21.6 km/h, she picks up a stone in her tire. draw a graph that shows the stone's height above the ground as she continues to ride at this speed for 2 s more. can someone please help me

asked by Allison on December 11, 2010
94. ### Thermochemistry

How many grams of water at 0 degrees C can be frozen into ice at 0 degrees C if 55.0 kJ of heat is removed? delta Hsolid= -6.01 kJ/mol

asked by Hannah on December 14, 2010
95. ### Physics

A 1.00-kg beaker containing 2.0 kg of oil (density = 916 kg/m3) rests on a scale. A 2.00-kg block of iron is suspended from a spring scale and is completely submerged in the oil. Find the equilibrium readings of both scales. I was able to find the

asked by Jimmy on December 3, 2010
96. ### algebra 1

what kind of shoes does a frog wear

asked by star on December 9, 2010
97. ### pre calculus

A parallelogram has a 70 degree angle and sides 6 cm and 10 cm long. How long are its diagonals?

asked by lelelelel on December 1, 2010
98. ### Math

A rectangular dog pen is to be constructed using a barn wall as one side and 60 meters of fencing for the other three sides. Find the dimensions of the pen that maximize the pen's area.

asked by booyah on December 18, 2010
99. ### chemistry

Find the percent by mass of sodium chloride in a 1.35 M NaCl solution. The density of the solution is 1.06 g/mL..............how do I go about doing this question thanks!