Friday

October 24, 2014

October 24, 2014

Total # Posts: 73,110

**Chemistry Urgent Help Please!**

If caffeine is soluble in hot benzene but insoluble in hot petroleum ether, how could you use this information to design a crystallization procedure?
*September 14, 2014*

**Math!**

1) What is the value of 19 + 5a^4 + 3b^2 when a = 2 and b = -4? (this is not a multiple choice question) but my answer is 147. 2)Combine the like terms to simplify the expression: 4 + 7xy^2 + 5y^3 + 10x -4xy^2 - 8x - 4y^3 + 9 - y^6 + 3x^2y^2 + 10x + 13 - y^3 + 3xy^2 + 2x + 13...
*September 14, 2014*

**physics**

Two cars A & B are coming closer to one another with speed 36 km/h and 72 km/h Separated by a distance 1500 m calculate : 1 . time interval after which two car meet . 2 . if acceleration of car A is 2m/s2 then calculate time interval after which car A & B Will meet. 3.if ...
*September 14, 2014*

**physics**

A train is moving parallel and adjacent to a highway with a constant speed of 24 m/s. Initially a car is 48 m behind the train, traveling in the same direction as the train at 35 m/s and accelerating at 3 m/s 2 . What is the speed of the car just as it passes the train?
*September 14, 2014*

**Chemistry Urgent Help Please!**

You use 100 ml ethylchloride (density 0.92 g/ml) to extract 25 ml ethylene bromohydrin (density 2.41 g/ml) mixed with 100 ml. Is the aqueous layer the lower or the upper layer. How could you easily test this. You dissolve sodium chloride 40g. in the above mixture. Assuming the...
*September 14, 2014*

**Chemistry**

2.91*10^6?
*September 13, 2014*

**Chemistry**

What is the velocity of an electron that has a de Broglie wavelength approximately the length of a chemical bond? Assume this length to be 2.5×10−10m .
*September 13, 2014*

**Math**

What is the parent function of h(x) = -x^2? Is it h(x) = x^2 or h(x) = -x^2? How can I describe h(x) = -x^3 as a transformation of the parent function of a cubic function? Do I just say that it is a reflection, or is there a way of saying it with numbers, as in h(x) = x^3 - 4?
*September 13, 2014*

**math**

2.Calculate the growth rate of Asset J dividends, we have to assume that future dividend payments will grow at a constant rate into the future forever. This constant rate can be estimated by calculating the average growth rate from the past dividends. Calculate Asset J’s ...
*September 13, 2014*

**HISTORY**

9-10. Since almost all Native American tribes were ,_______________ much of our information on their culture comes from the writings and stories of ___________________________. A. non-literate B. stupid C. Christians D. Muslims E. traders and missionaries F. All of the above I...
*September 13, 2014*

**chemestry**

How many molecules (not moles) of NH3\rm NH_3 are produced from 8.21×10−4gg of H2\rm H_2
*September 13, 2014*

**HISTORY**

15-20. Put the following events in chronological order, with A for the first to occur and G for the last to occur. g The “Pilgrims” land at Plymouth Rock, Massachusetts F Defeat of the Spanish Armada D Jacques Cartier leads the first French effort to colonize the New...
*September 13, 2014*

**HISTORY**

True False Columbus first sighted land in the New World near Newfoundland. I would say false because wasn't John Cabot the one to discover Newfoundland? Columbus was a devout adherent of A. Sunni Islam B. Hinayana Buddhism C. Orthodox Judaism D. Roman Catholicism E. ...
*September 13, 2014*

**HISTORY**

European overseas commercial expansion was aided by A.advances in shipbuilding and navigation B.the centralized power of nation-states C.European desires for wealth through trade D.the desire for alternative trade routes to bypass the Ottomans E.All of the above F. None of the...
*September 13, 2014*

**Science**

what is spectral broadening
*September 13, 2014*

**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 13 hours, with a standard deviation of 2.5 hours. It is desired to estimate the mean viewing time within two-quarter ...
*September 13, 2014*

**math**

when you throw up a cricket ball foot ball tennis ball and a basket ball which will go to a maximum height
*September 13, 2014*

**engineering science**

An object is kept in equilibrium on an incline by means of supporting force, which is at an angle of 30 degrees o the inclined. The weight of the obbject is 500N. The incline forms an angle of 45 degrees with the horizontal. The coefficent of the friction between the surfaces ...
*September 13, 2014*

**maths**

Ted recieved his pocket money He spent: 3/5 on games 1/10 on magazines What fraction of his pocket money is left? I dont understand how to do this question. Please help
*September 13, 2014*

**maths**

Thank you so much. I understand your method. Thank you again:)
*September 13, 2014*

**maths**

Debra recieved her £15 pocket money. She spent: 1/3 on magazines 2/5 on a necklace How much did she have left? My answer 1/3 of 15 is 5 2/5 of 5 is 2 2 pound is left Am I correct?
*September 13, 2014*

**History**

Discuss the causes of French Revolution of 1789
*September 13, 2014*

**HISTORY**

The most likely place of origin for Native Americans is A. Atlantis B. Asia C. Israel D. Polynesia E. Mars F. All of the above I would say central Asia, correct?
*September 13, 2014*

**HISTORY**

True or False Native American cultures generally had no concept of private property. I'm not sure whether to say true or false but I want to say false because Native Americans were aware of private property, they just weren't obsessive and greedy with it like the ...
*September 13, 2014*

**HISTORY**

15-20. Put the following events in chronological order, with A for the first to occur and G for the last to occur. g The “Pilgrims” land at Plymouth Rock, Massachusetts F Defeat of the Spanish Armada D Jacques Cartier leads the first French effort to colonize the New...
*September 13, 2014*

**physics**

A girl delivering newspapers covers her route by traveling 2.50 blocks west, 3.50 blocks north, and then 5.50 blocks east.
*September 12, 2014*

**In Response to Previous Math Question**

What parent function describes the set (-1, -1), (0, 0), (1, -1) (-2, -8), (2, -8)? So should I write f(x) = x^2 or f(x) = -x^2 for the parent function?
*September 12, 2014*

**Pre-Calculus/Trigonmetry**

Thank you, Damon
*September 12, 2014*

**Pre-Calculus/Trigonmetry**

Write the equation of the line that is parallel to the x-axis and goes through the point (1,4).
*September 12, 2014*

**Chemistry**

dfsdf
*September 12, 2014*

**Math**

What parent function describes the set (-1, -1), (0, 0), (1, -1) (-2, -8), (2, -8)?
*September 12, 2014*

**English**

Can you put this sentence into completely every word in present tense and still make this sentence make sense. Humans are never satisfied
*September 12, 2014*

**Math**

If I am traveling at a speed of 65 mi/h and graph the distance I travel over five hours, would the graph be linear?
*September 12, 2014*

**Biology**

A hydrogen ion is the same as a proton true or fasle
*September 12, 2014*

**Biology**

Breaking the hydrogen bond between two water molecules is called dissociation. true or false
*September 12, 2014*

**Pre-Calculus/Trigonometry**

Help please Tracy has a cell phone plan that provides 250 free minutes each month for a flat rate of $29. For any minutes over 250, Tracy is charged $0.35 per minute. Which of the following piecewise functions represents charges based on Tracy's cell phone plan? A. f(x)={...
*September 12, 2014*

**physics**

You are enjoying a day at the amusement park, riding a roller coaster, when suddenly a section of track up ahead crashes to the ground. You estimate that the cart is travelling at 5 m/s horizontally on the track before you begin to fall through the air. If the coaster leaves ...
*September 12, 2014*

**Canadian history**

Thank you very much Ms. Sue :)
*September 12, 2014*

**chemistry**

when 21.6g of carbon were burned in the presence of 73.9g of oxygen 16.3g of oxygen remain unreacted. What mass of carbon dioxide was produced
*September 12, 2014*

**programming**

write a program that performs a survey tally on vehicle. The program should prompt for the next person until a sentinel value of -1 is entered to terminate the program. Each person participating in the survey should choose their favorite from the following list-toyota,nissan,...
*September 12, 2014*

**programming**

write a program that performs a survey tally on vehicle. The program should prompt for the next person until a sentinel value of -1 is entered to terminate the program. Each person participating in the survey should choose their favorite from the following list-toyota,nissan,...
*September 12, 2014*

**Science (college level)**

dentify the fruit or vegetable you selected and relate the second law of thermodynamics to the changes in energy observed in Appendix CHow did the amount of energy gained compare to the amount of energy lost as heat at the second through fourth trophic levels? Considering the ...
*September 12, 2014*

**Math Problem (please help)**

IF x = 3 How much is 2(6x) + 2 (W)
*September 12, 2014*

**math**

fill in the following table, assets required for operation $2000 Case A - firm uses onlyequity financing Case B - firm uses 30% debt with a 10%interest rate and 70% equity Case C - firm uses 50% debt with a 12% interst rate and 50% equity
*September 12, 2014*

**physic**

what would the reading on the scale if the boxcar were moving at a constant velcity
*September 12, 2014*

**Finance**

Assets required for operation: $2,000 Case A – firm uses only equity financing Case B – uses 30% debt with a 10% interest rate and 70% equity Case C – firm uses 50% debt with a 12% interest rate and 50% equity
*September 12, 2014*

**physic**

A 22.2 kg mass attached to a spring scale rests on a smooth, horizontal surface. The spring scale, attached to the front end of a boxcar, reads T 44.1 N when the car is in motion. If the sring scale reads zero when the car is at rest, determine te acceleration of te car, when ...
*September 12, 2014*

**Math Problem (please help)**

If X= 3 How the is the perimeter of the rectangle 2(6X) + 2(W)=?
*September 12, 2014*

**Math (2nd time posting this)!**

So the first one would be 10^-6 and the second one would be 10^6 ?
*September 11, 2014*

**Math (2nd time posting this)!**

the best order-of-magnitude estimate for 0.00006? - 10^-3 - 10^-4 - 10^-5 * my answer - 10^-6 the best order-of-magnitude estimate for 789,000? - 10^7 - 10^6 - 10^5 - 10^4 *my answer I don't understand this quite well but I want to make sure my answers are correct. Thanks!
*September 11, 2014*

**Physics**

A military jet is flying with uniform motion at 9.3*10^2 m/s[S], the magnitude of which is approximately Mach 2.7. At time zero, it passes a mountain top, which is used as the reference point for this question. a)Construct a table showing the plane's position relative to ...
*September 11, 2014*

**Math**

the best order-of-magnitude estimate for 0.00006? - 10^-3 - 10^-4 - 10^-5 * my answer - 10^-6 the best order-of-magnitude estimate for 789,000? - 10^7 - 10^6 - 10^5 - 10^4 *my answer I don't understand this quite well but I want to make sure my answers are correct. Thanks!
*September 11, 2014*

**English**

1) is real-life one word? My teacher considered it to be. 2) then would Spanish-Americans be one word?
*September 11, 2014*

**Poll**

Have you ever been a hero? If so, what did you do
*September 11, 2014*

**?**

What challenge have you faced lately? ask at least 5 people
*September 11, 2014*

**Physics**

A car traveling 91km/h strikes a tree. The front end of the car compresses and the driver comes to rest after traveling 0.93m . What was the magnitude of the average acceleration of the driver during the collision? Express the answer in terms of "g's," where 1....
*September 11, 2014*

**college math**

v=1/3ttr^2h; h(geometry)
*September 11, 2014*

**college math**

How many liters of water should be evaporated from 110 liters of a 12% saline solution so that the solution that remains is a 20% saline solution
*September 11, 2014*

**college math**

A motorboat left a harbor and traveled to an island at an average rate of 11 knots. The average speed on the return trip was 10 knots. If the total trip took 4.2 hours, how far is the harbor from the island?
*September 11, 2014*

**physics**

How far is the rocket from the launch pad 8.50s later when the rocket engine runs out of fuel?
*September 11, 2014*

**Ecology**

8.Which of the following examples of an ecological study involves the ecosystem level of organization? A.The effects of human activities on biogeochemical cycling B.The effects of an invasive plant species on bird nesting sites C.The effects of competition on survival D.The ...
*September 11, 2014*

**MATH**

A motorboat left a harbor and traveled to an island at an average rate of 11 knots. The average speed on the return trip was 10 knots. If the total trip took 4.2 hours, how far is the harbor from the island?
*September 11, 2014*

**science**

Which of the following is a good study habbit.
*September 11, 2014*

**Physics**

At bat a baseball player hits a ball at a height of .889 m. The ball leaves the bat at 51 m/s at an angle of 81 degrees from the vertical. The ball skims the top of a 2.74 m wall as it leaves the field. a.) Draw position, velocity and acceleration graphs describing the ball ...
*September 11, 2014*

**math**

The length of a rectangle is 3 feet less than twice the width of the rectangle. If the perimeter of the rectangle is 144 feet, find the width and the length
*September 11, 2014*

**Accounting**

On March 1, 2013, the company lent a supplier $23,000 and a note was signed requiring principal and interest at 9% to be paid on February 28, 2014. If the journal entries are intrest recievable intrest revenue how much should I allocate to each section?
*September 11, 2014*

**chemistry**

If you have 0.833g of copper(II) sulfate, how many moles doo you have?
*September 11, 2014*

**math**

Write in an integer that represents your height on the teeter totter that is relative to the balance point height: you are 8 inches below the balance point height or you are 15 inches the balance point height---your height is the opposite or your friend is 12 inches above the ...
*September 11, 2014*

**chemistry **

Calculate the ÄHvap , in kJ/mol, for ethanol, given that the vapor pressure at 45.0°C is 155.0 torr. The normal boiling point of ethanol is 78°C. Express your answer to two decimal places.
*September 11, 2014*

**Chemistry please help**

104 ml of ethene, C2H4 is burned in 408 ml of oxygen, producing carbon dioxide and some liquid water. Some oxygen remain unreacted. Calculate the volume of carbon dioxide produced and the volume of oxygen remaining
*September 11, 2014*

**physics**

A hockey puck truck at ice level just clears the top of a glass wall that is 2.80 m high. The flight time to this point is 0.650 s, and the horizontal distance is 12.0 m. Find a.) the initial speed of the puck and b.) the maximum height it will reach.
*September 11, 2014*

**physics**

A hockey puck truck at ice level just clears the top of a glass wall that is 2.80 m high. The flight time to this point is 0.650 s, and the horizontal distance is 12.0 m. Find a.) the initial speed of the puck and b.) the maximum height it will reach.
*September 11, 2014*

**Math**

2/3 of miss lina's class were boys. there were between 2 and 14 boys. One day, twin girls joined the class. Now 3/5 of the students are boys. how many students are in miss lina's class now?
*September 10, 2014*

**Geometry**

Find AB in simplest form if A(0,3) and B(2,7) AB=___________ *I need help on this last problem I have! Someone please walk me through and how to get the answer
*September 10, 2014*

**Physics **

An 18-year-old runner can complete a 10.0-km course with an average speed of 4.39 m/s. A 50-year-old runner can cover the same distance with an average speed of 4.27 m/s. How much later (in seconds) should the younger runner start in order to finish the course at the same time...
*September 10, 2014*

**Quick geometry question**

My geometry teacher said something about when putting supplementary down for the answer doesn't quite necessarily work all the time. Is that true? Why is that? Would it be best just to put linear pair in for supplementary?
*September 10, 2014*

**physics**

The captain of a plane wishes to proceed due west. The cruising speed of the plane is 226 m/s relative to the air. A weather report indicates that a 32.0-m/s wind is blowing from the south to the north. In what direction, measured with respect to due west, should the pilot ...
*September 10, 2014*

**Physics-bobpursley Follow Up**

Initial Question: A rubber ball is dropped onto a ramp that is tilted at 20 degrees. A bounding ball obeys the "law of reflection," which says that the ball leaves the surface at the same angle it approached the surface. The ball's next bounce is 3.0 m to the ...
*September 10, 2014*

**chemistry**

A system initially contains 0.100 mol each of the three species sealed in a 10.0 L container. The temp was raised to a temp where the equilibrium constant Kc, is 12.6 for PCl3(g) + Cl2(g)--> <-- PCl5(g) Calculate the equilibrium concentration of all species.
*September 10, 2014*

**chemistry**

A system initially contains 0.100 mol each of the three species sealed in a 10.0 L container. The temp was raised to a temp where the equilibrium constant Kc, is 12.6 for PCl3(g) + Cl2(g)--> <-- PCl5(g) Calculate the equilibrium concentration of all species.
*September 10, 2014*

**Math**

How do you know which operation to choose when solving a real life problem?
*September 10, 2014*

**physics**

A kangaroo jumps straight up to a vertical height of 1.19m, how long was it in the air before returning on earth
*September 10, 2014*

**math**

A recipe that makes 7 servings calls for cup of apple juice and cup of cranberry juice. How many cups of juice are there per serving?
*September 10, 2014*

**Trig**

Two people decide to find the height of an obelisk. They position themselves 25 feet apart in line with, and on the same side of, the obelisk. If they find that the angles of elevation from the ground where they are standing to the top of the obelisk are 65 degrees and 44 ...
*September 10, 2014*

**business math**

On May 1, 2004 the Jones Company received a bank statement that showed a $2,950 balance. Mr. Jones showed a $4,010 checking account balance. The bank did not return check No. 124 for $1080 and check No. 138 for $720. A $3,200 deposit made on April 30 was in transit. The bank ...
*September 10, 2014*

**college algebra**

A doctor prescribes an ointment that is 4% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How many ounces of each should the pharmacist use to make a 3-ounce tube?
*September 10, 2014*

**college algebra**

An executive invests $22,000, some at 8% and some at 6% annual interest. If he receives an annual return of $1,680, how much is invested at each rate?
*September 10, 2014*

**physics**

A toy rocket, launched from the ground, rises vertically with an acceleration of 28 m/s2 for 9.5 s until its motor stops. Disregarding any air resistance, what max- imum height above the ground will the rocket achieve? The acceleration of gravity is 9.8 m/s2 . Answer in units ...
*September 10, 2014*

**physics**

A ball player catches a ball 3.70s after throwing it vertically upward, what speed did he threw it
*September 10, 2014*

**Algebra**

Find the price of any container of lemonade at a local grocery store. (You can also find prices in advertisements and on the Internet.) Make sure you write down the number of fluid ounces in the container. Determine the unit price and post the information.
*September 10, 2014*

**college algebra**

A taxi cab company charges a flat fee of $3.30 and then an additional $2.20 for each mile. If a taxi fare is $29.70, how many miles was the trip?
*September 10, 2014*

**Physics**

Henry Heavyweight weighs 1400N and stands on a pair of bathroom scales so that one scale reads twice as much as the other. What are the scale readings?
*September 10, 2014*

**English**

If nonsense were actually said by a person, then which is correct? He told it off as "Nonsense." He told it off as "nonsense." Is punctuation correct?
*September 10, 2014*

**Math**

Write a word phrase for each algebraic expression. 14.1 - w z/8 - 9
*September 10, 2014*

**Math**

Compare the numbers in each exercise using an inequality symbol. 5 2/3, square root 29
*September 10, 2014*

**Math**

Write a word phrase for each algebraic expression. 14.1 - w and z/8 - 9
*September 10, 2014*

**maths**

classify the following into quadrilaterals: triangle,rectangle,pentagon,hexagon,parralelogram
*September 10, 2014*

**Math**

-20 is the answer.
*September 10, 2014*

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