Thursday
October 27, 2016

# Posts by bill

Total # Posts: 830

Chemistry (Titrations)
In order to standardize a KMnO4 solution, 0.2848 g Fe(NH4)2(SO4)2·6H2O was dissolved in 25 mL 0.18 M H2SO4. The KMnO4 solution was added to the Fe(NH4)2(SO4)2·6H2O solution until a pale pink color persisted. The titration took 24.2 mL of KMnO4 solution. What is ...
November 30, 2014

10.55 Consider an experiment with four groups, with eight values in each. For the ANOVA summary table below, fill in all the missing results: Source Degrees of Freedom Sum of Squares Mean Square (Variance) F Among groups c - 1 = ? SSA = ? MSA = 80 FSTAT = ? Within groups n - c...
November 27, 2014

Math
how to write 4(x+2)+3x+2(x-y) in the distribt. property form
November 23, 2014

Chemistry
Calculate the pH of a 1.19M sodium formate, HCOONa, solution.
November 23, 2014

Chemistry
Calculate the pH of a buffer solution made by mixing 231 mL of a 1.04M trimethylamine (CH3)3N solution with 176 mL of a 1.38M trimethylammonia chloride, (CH3)3NHCl solution. Enter your answer to TWO decimal places. DO NOT use scientific notation.
November 23, 2014

Chemistry
How many grams of nitric acid (HNO3) must be dissolved in 590 ml of water to make a solution with a pOH = 10.1? Select one: a. 2.9 x 10-9 g b. 7.9 x 10-3 g c. 4.7 x 10-3 g d. 7.9 x 10-6 g e. 7.4 x 10-5 g
November 23, 2014

physics
A bee flies to a flower 583 m due south of its hive. The bee’s speed in still air is 0.68 m/s, and there is a wind blowing toward the south at 0.16 m/s. How long will it take the bee to travel to the flower and back to the hive? Answer in units of s
November 18, 2014

Chemistry (Acid&Base)
How many mL of 0.203 M HCl(aq) are required to prepare a diluted solution that has a concentration of 0.0433 M in a 100-mL volumetric flask?
November 16, 2014

Chemistry
Consider the reaction 2 SO2(g) + O2(g) in equilibrium with 2 SO3(g) . At 25°C delta H° = -197.78 kJ and delta S° = -187.95 J/K. Using this information, calculate the equilibrium constant for the reaction at -32°C. (R = 8.314 J/K) Enter your answer using TWO ...
November 16, 2014

statistics
It seems that people are choosing or finding it necessary to work later in life. Random samples of 200 men and 200 women age 65 or older were selected, and 80 men and 59 women were found to be working. At á = 0.01, can it be concluded that the proportions are different
November 15, 2014

Statistics
Suppose that the probability that a new medication will cause a bad side effect is 0.03. If this medication is given to 150 people, what is the probability that more than three of them will experience a bad side effect?
November 14, 2014

physics
Rubber tires and wet blacktop have a coefficient of kinetic friction of 0.5. A pickup truck with a mass 750 kg traveling 30.0 m/s skids to a stop. (a) what is the size and direction of the frictional force that the road exerts on the truck? (b) Find the acceleration of the ...
November 11, 2014

calculus related rates
Boyle’s law for the expansion of a gas is PV = k, where P is the pressure (in pounds per unit of area), V is the volume of the gas, and k is a constant. Find the expression that shows the rate of change of the pressure as related to the rate of change of the volume. dP/...
November 11, 2014

Physics
A dog sled weighing 750 lb is pulled over level snow at a uniform speed by a dog team exerting a force of 60 lb. find the coefficient of friction.
November 11, 2014

physics
A plane cruising at 247 m/s accelerates at 28 m/s 2 for 8.7 s.How far will it have traveled in that time?
October 22, 2014

physics
A car travels in a straight line for 2.8 h at a constant speed of 53 km/h . What is its acceleration? Answer in units of m/s 2
October 21, 2014

physics
Water is poured into a container that has a leak.The mass 'm' of the water is given as a function of time 't' by, m=5t^0.8 -3t + 20 , with t>=0, mass in grams and t in seconds A) at what time is the water mass greatest,and B) what is the greatest mass? In ...
October 19, 2014

Physics
The space shuttle, with an initial mass M = 2.41×106 kg, is launched from the surface of the earth with an initial net acceleration a = 26.1 m/s^2. The rate of fuel consumption is R = 6.90×103 kg/s. The shuttle reaches outer space with a velocity of vo = 4632. m/s...
October 13, 2014

physics
A space probe is to be put into a circular orbit of radius 42.00 km about an asteroid. At this radius the magnitude of the gravitational acceleration, normally referred to as the "gravitational field", is 1.00×10-3 meters per second squared. What speed, in ...
October 13, 2014

help
If BaSO4 ppt is isn't washed or dried adequately how will this effect the sulfate percent error determination?
October 12, 2014

Chem lab
Student Calamity reported a final yield of 50%. List four things she might have done wrong to account for this yield. Student Overachiever reported a final yield of 115%. List two things he might have done wrong to account for this yield.
October 11, 2014

chemistry
you have not added enough sodium hydroxide to precipitate all the copper as copper hydroxide. How could you tell that not all the copper had precipitated?
October 11, 2014

physics
A mass m = 6.0 kg is attached to the lower end of a massless string of length L = 27.0 cm. The upper end of the string is held fixed. Suppose that the mass moves in a circle at constant speed, and that the string makes an angle theta = 28° with the vertical, as shown in ...
October 7, 2014

statistics
There are two companies that sell the medication, Company A and Company B. Company A’s tablets have a mean of 5 mg of medication and Company B’s tablets also have a mean amount of 5 mg of medication. This information would lead you to believe that it would make no ...
September 28, 2014

Math
Find the locus of points that satisfy (a) |z+1| = |z+i| (b) Re z = |z-1| and sketch them in the complex plane.
September 22, 2014

AP Alegebra
simplify (sqrt(x)+1)/(sqrt(x)-1)
September 7, 2014

Physics
just submitted the answer... to two sig figs it would be 53000 or 5.3x10^4
August 27, 2014

math
have 10 boxes each box contains 50 peices and we're selling for 8.00 per box. If I had to repackag them into 20 pieces each how much would I sell the repacked boxes for ? And how much for the quantity ?
August 8, 2014

Physics
Two charged particles are fixed on the x-axis 11 cm apart. The one on the left has a net charge of +25uc and the one on the right has a net charge of -15uc. What is the magnitude of the electric field 15 cm to the right of the negative charge? How do you solve this problem? ...
August 3, 2014

Statistics
E=.7624
June 16, 2014

Math
For a party; Mike is making an eight layer torte, which consists of eight 7-inch diameter cake layers with a cream topping on each. He knows that one recipe of cream topping will cover 55 square inches of cake. How many batches of the topping must he make to complete his torte...
June 12, 2014

Math
A model plane flies 18ft per 2 seconds. What is the plane's speed in miles per hour? Round to the nearest tenths.
April 27, 2014

Math
Write an algebraic expression for "15 less than the product of the square of x and 5."
April 20, 2014

CHEMISTRY
WHAT IS THE EMPIRICAL FORMULA FOR A COMPOUND THAT HAS 200GRAMS. 97.30 GRAMS OF CARBON, 16.22 GRAMS OF HYDROGEN, AND THE REST IS OXYGEN?
April 12, 2014

Math
Jim paid \$ 5.55 for 1 notepad and 7 pencils. Anne paid \$ 12.28 for 3 notepads and 2 pencils. How much does each notepad cost? Show all work
April 7, 2014

statistic
Roll two 6-sided dice and examine their sum. a) How long will it take to roll "snake-eyes" (a pair of ones)? b) What is the probability of rolling a sum of 7 on the first roll? c) What is the probability of rolling a sum of 7 on the fourth roll? d) What is the ...
April 1, 2014

College Physics
A doubly charged ion is accelerated to an energy of 33.0 keV by the electric field between two parallel conducting plates separated by 1.70 cm. What is the electric field strength between the plates?
March 24, 2014

math
If a took a loan of \$12000 for one year at 9.5% simple interest what would be my interest
March 19, 2014

math
if a took a loan out for \$12000 for one year at 10% simple discount what would be my interest
March 19, 2014

Chem
When 100mL of 0.60mol per liter K3BO3 is added to 200 mL of 0.40 mol per liter Ca3(BO3)2 Find a)moles of K3BO b) moles of Ca(BO3)2 c)final concentration of K+ d)final concentration of Ca+2 e) final concentration of BO3 negative 3
March 19, 2014

Chem
In the lab a 3.3mol per liter solution was prepared by adding H2O to 140mL of a 4.3mol Per Liter solution of HCL. How much water was added?
March 19, 2014

Math
It's actually C
February 5, 2014

math
factor 2x^2+7x+6=0
January 26, 2014

transportation economic
In your own words, describe the meaning of marginal cost. You normally buy a crate of wine for \$75. One crate has 6 bottles of wine. After a month, the store clerk informs you that the same crate of wine now costs \$82. However, there are 7 bottles in a crate. To the nearest ...
January 19, 2014

biology
if there is no oxygen for the glycolysis what process would that be called?
November 6, 2013

physics
a space probe launched from earth and orbits at a distance of 15,000 m from earth's center, the gravitational force is 500 N. What is the size of force when it is 25,000 m from earth.
November 5, 2013

Physics
A hang glider and its pilot have a total mass equal to 120 kg. While executing a 360 degree turn, the glider moves in a circle with an 8-m radius. The gliders mass is 10 m/s. a) what is the net force on the hang glider? b) What is the acceleration?
November 5, 2013

Econ
When the law of diminishing returns applies, which of the following would rise with increased employment of labor, ceteris paribus? A. Fixed costs B. Marginal cost C. Marginal revenue D. The wage rate
November 3, 2013

statictics
Either one
October 27, 2013

Algebra
1800 (x+20) 1800x + 20(1800) or 1800x + 36,000 are the expressions all equivalent? How can you determine if they are equivalent?
October 24, 2013

Math
The manager of Pine Town Furniture purchased a new copier for \$28,000. She plans to keep it for four years, at which point she expects to trade the copier in and receive \$6000 credit toward the purchase of a new machine. She is going to use straight-line depreciation on the ...
October 22, 2013

Math
The total cost of renting a car is a function of the basic charge, insurance, and the number of miles driven. Suppose a compact car costs \$0.10 per mile plus \$30 in basic charges and insurance. A mid-size car costs \$50 in basic charges and insurance plus \$0.10 per mile.
October 22, 2013

organic chemistry
I need help understanding how to differentiate between isomers and resonance structures in skeletal structures. Specifically, here is an image to a problem with the answers: i.imgur. com /mz3URSa.jpg (remove spaces) The left most structure is the reference structure and the ...
October 19, 2013

science help!!!
Thank you Josslyn you are the best i got 100%
October 18, 2013

science
If you have 10 lbs shrimp at 80 deg F how much ice would it take to reach 50 deg F in 10 minutes?
August 7, 2013

alg
5x-10/5 ?
July 10, 2013

alg
−(6p + 12
July 10, 2013

Physics
Synchronous communications satellites are placed in a circular orbit that is 3.59 107 m above the surface of the earth. What is the magnitude of the acceleration due to gravity at this distance?
June 30, 2013

physics
A block is pressed against a vertical wall by a force , as the drawing shows. This force can either push the block upward at a constant velocity or allow it to slide downward at a constant velocity. The magnitude of the force is different in the two cases, while the ...
June 30, 2013

physics
Geosynchronous communications satellites are placed in a circular orbit that is 3.59 107 m above the surface of the earth. What is the magnitude of the acceleration due to gravity at this distance?
June 27, 2013

microeconomics
The cost of producing flat-screen TVs has fallen over the past decade. Let’s consider some implications of this fact. A.) Draw a supply-and-demand diagram to show the effect of fallen production costs on the price and quantity of flat-screen TVs sold. B.) In your diagram...
June 9, 2013

Pseudocode Format
Need help writing this using pseudocode format: Carly gets paid annually, and she would like a program that will figure out the amount of money she will be receiving each pay period. To make this simpler, we are not worried about any deductions.
May 21, 2013

Pseudocode Format
Need help writing this into Pseudocode Format: Robert has a van rental company, and he wants a program that determines the total cost of renting a van from him. His customers will pay a base fee (currently set at \$50), plus a charge per mile (currently \$.25 a mile).
May 21, 2013

Chemistry
A certain gas has a solubility of .50 g/L under a pressure of 1500 torr. What would its solubility be a 2250 torr?
May 6, 2013

Physics
In two successive chess moves, a player first moves his queen four squares forward, then moves the queen three steps to the left (from the player’s view). Assume each square is 4.0 on a side.
April 20, 2013

Physics
In two successive chess moves, a player first moves his queen four squares forward, then moves the queen three steps to the left (from the player’s view). Assume each square is 4.0 on a side.
April 20, 2013

Physics
In two successive chess moves, a player first moves his queen four squares forward, then moves the queen three steps to the left (from the player’s view). Assume each square is 4.0 on a side.
April 20, 2013

Physics
In two successive chess moves, a player first moves his queen four squares forward, then moves the queen three steps to the left (from the player’s view). Assume each square is 4.0 on a side.
April 20, 2013

Science
Person weighing 650N lies on a bed of nails,each nail has area of 1m2 Assume 4Nm^-2 pressure is painful what is the smallest number of nails they could lay on and not be hurt
April 9, 2013

Chemistry
How many milliliters of 1.0 M NaOH must be added to 200. mL of 0.10 M NaH2PO4 to make a buffer solution with a pH of 7.50? (5 points)
April 4, 2013

Math
What is the perimeter of a trapeziod with an area of 96
March 31, 2013

physics
A boy is pushing his sled up a snowy slope. The sled has a mass of 20.4 kg and weighs 200 N. The boy pushes with a constant force of 75 N. The sled travels a distance of 10 m and gains 3 m in height. When the sled reaches the top, it is traveling 2 m/s. What is the efficiency ...
March 27, 2013

Statistics
A pharmaceutical company claims its new medication relieves painful symptoms caused by tension headaches within 15 minutes. To investigate this claim, a local health clinic conducts a study of 45 patients who suffer from chronic tension headaches. Each patient is given ...
March 26, 2013

Statistics
According to a recent pole only 21% of Americans were satisfied with the direction the U.S. is heading. To investigate the reliability of the report an independent polling organization surveyed 500 Americans and inquired as to whether or not they were satisfied with the way ...
March 26, 2013

Statistics
Assume the weights of men are normally distributed having a mean of 185 lbs and a standard deviation of 17 pounds. A. Calculate the probability a randomly selected man weights less than 225 lbs B. Approximately 72% of men’s weights exceed how many pounds. C. In a random ...
March 26, 2013

Statistics
Assume the wait time to see a cardiologist at a certain clinic are uniformly distributed between 7 minutes and 23 minutes. Calculate the probability a randomly selected patient waits at least 18 minutes to see the cardiologist. The random variable, Z, is associated with a ...
March 26, 2013

Statistics
A Manufacturer of torque converters claim only 1% of them are defective. A. Calculate the Mean number of defective converters in a shipment of 500 converters. B. Calculate the standard deviation in the defective torque converters in a shipment of 500 converters. C. Would it be...
March 26, 2013

Statistics
A Manufacturer of torque converters claim only 1% of them are defective. A. In a shipment of 12 torque converters calculate the probability exactly 2 converters are defective. B. In a shipment of 35 converters, calculate the probability at least 1 converter is defective.
March 26, 2013

Statistics
In a certain game of chance a person pays \$5 to play a game. A person randomly selects 2 integers ranging from 0-99. The host of the game then uses a random number generator to select 2 integers ranging from 0-99. If the players values and hosts values agree (in any order), ...
March 26, 2013

Statistics
Use this information to calculate the mean and standard deviation of this random variable. P(x)- .25, .05, .55, .15
March 26, 2013

Statistics
A standard deck of 52 playing cards is composed of 4 suits. Each mix contains 13 cards. Jacks, Queens, and Kings are considered face cards. Assume three cards are selected without replacement. Calculate the probability of drawing two hearts, followed by a spade.
March 26, 2013

Chemistry
A solution is prepared by dissolving 571.6 g of H 2SO4 in enough water to make 1000.0 mL of solution. The solution has a density of 1.3294 g/mL. (molar mass of H2SO4 = 98.08). What is the molar concentration of the solution?
March 24, 2013

chemistry
What mass of F2 is needed to produce 116 g of PF3 if the reaction has a 77.4% yield?
March 10, 2013

Physics
35 m/s
February 24, 2013

Pre-calculus
Use this equation. X=t*v*cos(theta) So 2*102*cos67=79.70915021
February 19, 2013

Pre-calculus
79.70915021
February 19, 2013

Statistics
In order to compare two kinds of feed, thirteen pigs are split into two groups, and each group received one feed. The following are the gains in weight (kilograms) after a fixed period of time: Feed A: 8.0 7.4 5.8 6.2 8.8 9.5 Feed B: 12.0 18.2 8.0 9.6 8.2 9.9 10.3 We wish to ...
February 18, 2013

World history
Confucius believed that human beings are essentially A. gods. B. evil. C. good. D. sinful.
February 9, 2013

chemistry
What has the higher normal melting point: CHI3 or CHF3? The answer in the book is CHI3. So I'm assuming the answer is CHI3 because Iodine is the bigger and will form larger london dispersion forces, but isn't a stronger dipole moment formed in CHF3 because fluorine is ...
January 16, 2013

Physics conceptual questions
You have a drink that you want to cool off? You could put in 100 g of ice or 100 g of water, both at 0 degree C. Which one would be more effective in cooling your drink? Why?
January 14, 2013

Math
January 11, 2013

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