Saturday

April 18, 2015

April 18, 2015

Total # Posts: 530

**Physics**

A fire helicopter carries a 520-kg bucket of water at the end of a 20.0-m long cable. Flying back from a fire at a constant speed of 40.0 m/s, the cable makes an angle of 38.0° with respect to the vertical. Determine the force exerted by air resistance on the bucket.
*March 8, 2012*

**Chemistry **

A student titrated 1.852 g of a mixture containing potassium hydrogen phthalate, KHP....? A student titrated 1.852 g of a mixture containing potassium hydrogen phthalate, KHP, with 0.163 M NaOH solution. She recorded an initial buret reading of 0.84 mL and a final buret ...
*March 7, 2012*

**Chemistry**

Determine the molarity of a sodium hydroxide solution? if 37.34 mL of it are required to neutralize 1.922 g of citric acid. balanced equation- 3NaOH(aq)+H3C6H5O7-->3H2O(l)+NaC6H5O7(aq… ***Plesae show steps.
*March 7, 2012*

**Life orientation RAPHELA**

ICASA AKA INDEPENDENT COMMUNICATION AUTHORITY OF SOUTH AFRICA
*March 6, 2012*

**Life orientation**

Explain three checks and balances that are in place in south africa that control and regulate the media
*March 6, 2012*

**Chemistry**

Zn metal was allowed to react with hydrochloric acid to produce hyrdogen gas.This gave a total of 555mL of gas collected over water at 20C and a pressure of 747mm of Hg. How many moles of hydrogen were collected? The vapor pressure of water at 20C is 18mm Hg.
*March 5, 2012*

**Chemistry **

How many liters of hydrogen gas can be made from 65.5g of magnesium at STP? Magnesium reacts to sulfric acid according to this equation... Mg+H2SO4-->MgSO4+H2
*March 5, 2012*

**Chemistry **

Using the van der Waals equation, determine the pressure of 436.0g of SO2(g) in a 7.30-L vessel at 725k.? For SO2(g), a=6.865L^2•atm/mol^2 and b=0.05679L/mol. (R=0.0821L•atm/(K•mol))
*March 5, 2012*

**Chemistry**

What how can I calculate the amount in moles and the mass in grams of KOH needed to convert 1.50 g of aluminum to KAl(OH)4. Balanced equation = 2 Al (s) + 2 KOH (aq) + 6 H2O (l)->2 KAl(OH)4 (aq) + 3 H2 (g) Please show steps ..
*February 29, 2012*

**Chemistry **

If the percent yield was 81.5%, how many grams of aluminum were used to prepare 20.0 g of potassium alum?
*February 29, 2012*

**Chemistry **

Calculate the percent yield of alum if you obtained 75.0 g of potassium alum from 5.00 g Al.
*February 29, 2012*

**Chemistry **

How many moles and how many grams of potassium alum, KAl(SO4)2 · 12 H2O, can be prepared from 5.00 g of aluminum?
*February 29, 2012*

**Chemistry**

Which one ?
*February 29, 2012*

**Chemistry**

Calculate the amount in moles and the mass in grams of KOH needed to convert 1.50 g of aluminum to KAl(OH)4. Balanced equation = 2 Al (s) + 2 KOH (aq) + 6 H2O (l)->2 KAl(OH)4 (aq) + 3 H2 (g)
*February 29, 2012*

**Chemistry **

Calculate the volume (in mL) of 9.0M H2SO4 that you would need to convert 0.070 moles of KAl(OH)4 to K2SO4 and Al2(SO4)3 according to the following equation: 2 KAl(OH)4 + 4 H2SO4->K2SO4 + Al2(SO4)3 + 8 H2O
*February 29, 2012*

**Chemistry **

Calculate the amount in moles and the mass in grams of KOH needed to convert 1.50 g of aluminum to KAl(OH)4. Balanced equation = 2 Al (s) + 2 KOH (aq) + 6 H2O (l) ¨ 2 KAl(OH)4 (aq) + 3 H2 (g)
*February 29, 2012*

**Calculus AP need help!**

oops.. i thought 1/2 to -3/2. now i understand. thanks
*February 28, 2012*

**Calculus AP need help!**

1. f(x)=√5x+6, find f'(x) 2. f(x)=√4x^2+3x+4, find f'(x). i got stuck. f(x)=√5x+6=(5x+6)^1/2 f'(x)= 1/2(5x+6)^-3/2*(5).
*February 28, 2012*

**algebra. help!!**

my answer is 63.56. i dont know if its right answer. here this problem: It takes Scott an average of 45 min to prune 1 tree. Victor takes 65 min to prune a tree on average. The Scott-Victor Pruning Service has the contract to prune 92 trees in Flagstaﬀ, AZ. How long ...
*February 26, 2012*

**COLLEGE CALCULUS. HELP!**

Find the derivative of the function. 1. F(x)= (1+2x+x^3)^1/4 2. f(t)= (1+tant)^1/3
*February 26, 2012*

**COLLEGE CALCULUS. HELP!**

i got it thanks
*February 25, 2012*

**COLLEGE CALCULUS. HELP!**

hey how u get 324x?
*February 25, 2012*

**COLLEGE CALCULUS. HELP!**

i got stuck
*February 25, 2012*

**COLLEGE CALCULUS. HELP!**

Let f(x)=(-3x^2+6)^4(9x^2+7)^14, Find f'(x). f'(x)= (-3^2+6)^4 d/dx(9x^2+7)^14+(9x^2+7) d/dx(-3x^2+6)^4 =(-3x^2+6)x14(9x^2+7)^13 d/dx(9x^2+7)+(9x^2+7)^14x4(-3x^2+6)^3 d/dx(-3x^2+6) =14(-3x+6)^4(9x^+7)^13 (18x)+ 4(9x^2+7)(-3x^2+6)^3 (-6x)
*February 25, 2012*

**Chemistry**

The concentration of Pb+2 in a sample of wastewater is to be determined by using gravimetric analysis. To a 100.0-mL sample of the wastewater is added an excess of sodium carbonate, forming the insoluable lead(II)carbonate (267.2092 g/mol) according to the balanced equation ...
*February 22, 2012*

**Chemistry**

In basic solution, H2O2 oxidizes Cr+3 to Cro4^-2 and is reduced to OH-. What is the balanced equation?
*February 22, 2012*

**Chemistry **

What mass of oxalic acid dihydrate , H2C2O4•2H2O, is required to prepare 220.0 ml of a 1.28 M solution of oxalic acid ?
*February 22, 2012*

**Chemistry**

A student must prepare 2.00 L of 0.100 M Na2CO3 (106 g/mol) Which is the best procedure for preparing this solution ?
*February 22, 2012*

**Chemistry**

A 30.00-mL sample of weak acid is titrated with 0.0167 M NaOH. At the endpoint , it is found the 40.35 mL of titrant was used. What was the concentration of the weak acid ?
*February 22, 2012*

**Chemistry **

A student must prepare 2.00 L of 0.100 M Na2CO3 (106 g/mol) Which is the besst procedure for preparing this solution ?
*February 22, 2012*

**Chemistry**

How many grames of lithium nitrate LiNO3 (68.9 g/mol) are required to prepare 174.1 mL of a 0.698 MLiNO3 solution ?
*February 22, 2012*

**Chemistry**

What is the net ionic equation for the reaction that occures between nitrouse acid and strontium hydroxide ?
*February 22, 2012*

**Chemistry**

What is the net ionic equation for the reaction that occures between nitrouse acid and strontiun hydroxide ?
*February 22, 2012*

**Project Management **

What elements do you think are critical when conducting project meetings and why do you think they are important? How do project meetings help with managing inter-organizational relations? Be sure to address the concept of group think in your discussion.
*February 22, 2012*

**Business**

Select an organization with which you are familiar and discuss the impact of that organization’s level of social responsibility on a stakeholder group of your choice
*January 29, 2012*

**Business**

Select an organization with which you are familiar and discuss the impact of that organization’s level of social responsibility on a stakeholder group of your choice
*January 24, 2012*

**Chemistry **

A lightyear is a unit of length equal to the distance that light travels in 1 year. What is 1 lightyear expressed in units of meters? The speed of light is 3.00 × 100^8 m/s.
*January 22, 2012*

**Chemistry**

Could you explain how or why ?
*January 18, 2012*

**Chemistry**

The enthalpy of combustion of benzoic acid is –26.4 kJ/g. What is the enthalpy of combustion expressed in joules per kilogram?
*January 18, 2012*

**chemistry**

How many 400-mg aspirin tablets can be made from 40.0-kg of aspirin?
*January 18, 2012*

**scientific notations**

7.13x10^11 = 713,000,000,000 - To convert from scientific notation to standard from simply move the decimal point 11 spaces to the right after the 7 . 10's power will tell you how many spaces to move to decimal , if its positive to the right and if its negitave to the left...
*January 18, 2012*

**Medical Coding**

what are the 2 diagnosis codes
*January 10, 2012*

**Statistics**

are the following statements, Ho:=10 and Ha:equal to or less than, a valid pair of null and alternative hypothesis?assume that in a hypothesis test with null hypothesis Ho : u = 12.0 at a = 0.10, that a value of 16.0 for the sample mean results in the null hypothesis being ...
*November 19, 2011*

**PHYSICS**

On the planet jupiter , g is 2.5m/s². What does this mean?
*November 5, 2011*

**Trig**

Find the exact value of tan 5pi/12 using the half-angle identity.
*October 15, 2011*

**Chemistry**

A 0.250g smaple of magnesium-aluminum alloy dissolves completely in an excess of HCl(aq). When the liberated H2(g) is collected over water at 29C at 752torr, the volume is found to be 297mL. The vapor pressure of water at 29C is 30.0torr. What is the mass percentage of ...
*October 9, 2011*

**Chemistry**

why is a water molecule is much more likely to give up a proton than a methane molecule
*October 2, 2011*

**londontowne**

divide the product of 8 and 1/2 by .02
*September 3, 2011*

**History**

Is History an art or a science?
*September 3, 2011*

**chemistry**

why is 1mol of so3 gas higher in entropy than so2 gas
*August 22, 2011*

**Calculus**

A team has been working to convert diesel-powered cars to run just as efficiently on used cooking oil! They want to compare the mileage and speed of their prototype with that of the diesel-powered car. The prototype is 100 meters south of an intersection, while the diesel car ...
*August 1, 2011*

**Calculus**

Part of a circuit has two resistors connected in parallel as shown in the figure. R(1) is a constant resistor of 10 ohm, while R(2) is a variable resistor with resistance that varies at a rate of 2 ohms per minute. The total, or effective, resistance, R, provided by this ...
*July 29, 2011*

**calculus**

Using L'Hôpital's rule, evaluate lim of xe^(-x) as x approaches infinity
*July 29, 2011*

**calculus**

Find the average value of the function f(x) = (2x - 5)^2 on the interval [1, 2].
*July 29, 2011*

**Earth Science**

In what ways can sea level be lowered? What effect might this have on existing life forms? I can't find it in my textbook. Can somebody helps??????? THANKS A LOT!!!!!
*July 27, 2011*

**Earth Science**

How is the local hydrologic cycle affected by the practice of drawing drinking water from a river and then returning sewage to the same river? Can anyone please help?????? THANKS A LOT!!!!!
*July 20, 2011*

**Physics**

A 6 µC charge is placed at the origin and a second charge is placed on the x-axis at x = 0.34 m. If the resulting force on the second charge is 4.0 N in the positive x-direction, what is the value of its charge?
*July 14, 2011*

**Chemistry**

Since the oxidation number of Chromium is +3, and the oxidation number of Silicon is -4. Why is the chemical formula for Chromium III Silicide Cr3Si2? Can somebody please explain to me please???????THANKS A LOT!!!
*July 13, 2011*

**Chemistry**

Oxygen has a boiling point of 90K, and nitrogen has boiling point of 77K. Which is a liquid and which is a gas at 80K? I tried to look into the phase diagrams, but I still don't understand. Can somebody please help and explain to me??? THANKS A LOT!!!
*July 10, 2011*

**math**

How did math originate?
*July 6, 2011*

**math for elemetary school teachers**

need to create a number system using only: A=1, B=2, C=3, D=4 and Zero=0. Help
*June 4, 2011*

**finance**

The company has an open invoice for $100 but then chooses to take the 2% discount offered and pay $98 if paid within 10 days.
*May 26, 2011*

**finance**

A corporation’s pretax net income of $1,000,000 is taxable based on 30% of the first $300,000, 35% of the next $300,000, and 40% of the balance:
*May 26, 2011*

**movement and music**

morning
*May 20, 2011*

**finance**

A company began the year with retained earnings of $1,000. Net income for the year was $250, it repaid $350 of its line of credit balance, and it paid dividends to its shareholders of $200. What was the company’s retained earnings at the end of the year?
*May 20, 2011*

**finance**

Hauser Sports had sales in 2010 of $750,000, cost of sales of $500,000, average accounts receivable of $100,000 and average inventory of $225,000. How many days, on average, does it take Hauser Sports to sell its inventory assuming that all sales are on credit?
*May 20, 2011*

**finance**

The Cookie Shoppe expects sales of $500,000 next year at a 5% pretax profit margin and an average tax rate of 35%. If it chooses to pay out 30% of its earnings as dividends, what is the projected increase in retained earnings
*May 20, 2011*

**finance**

Central Systems has a pretax cost of debt of 8%, an average tax rate of 30%, and a cost of equity of 14%. If the company’s debt-equity mix is 50%-50%, what is Central’s weighted average cost of capital?
*May 20, 2011*

**finance**

Chelsea Fashions is expected to pay an annual dividend next year of $1.00 per share. The market price of the stock is $25 and the growth rate of dividends is expected to be 5%. What is Chelsea’s cost of equity?
*May 20, 2011*

**finance**

What is the net present value of a project that has an upfront cash outlay of $30,000, and generates cash inflows of $15,000 in year 1, $20,000 in year 2, and $25,000 in year 3 assuming that the company’s cost of capital is 15% per year?
*May 20, 2011*

**finance**

How much should you be willing to pay for one share of stock if the company just paid a $1 dividend, you expect the dividends to increase by 5% annually, and you need a 12% return on your investment
*May 20, 2011*

**geometry**

Find the supplement to the angle whose measure is 85 degrees.
*April 7, 2011*

**Frankenstein**

How does shelly keep mystery and terror along with supernatural elements in chapters 8-10
*March 30, 2011*

**geometry**

donald's garden is rectangular the garden is 14 metres long it's perimeter is 47 metres how wide is the garden
*March 23, 2011*

**math**

you have $60, consisting of quarters and pennies. write an inequality that shows the different number of coins in piggy bank
*March 20, 2011*

**trig**

The number of a fraction is three more than twice the denominator. The fraction simplified is equal to 9/4 Find the fraction
*March 16, 2011*

**Physics**

find the height from which you would have to drop a ball so that it would have a speed of 9.0 m/s
*March 3, 2011*

**French**

I'm supposed to come up with something in the imparfait that begins with "Quand j'étais petite, ... but my vocabulary is very limited so I don't really know what to write. Any suggestions?
*March 1, 2011*

**chemistry**

what is the name of the compound made ofrom chlorine and magnesium
*February 8, 2011*

**science**

an astronaut in space vehicle traveling from earth to the moon is in potential danger of being harmed by the sun's ultraviolet radiation.
*January 24, 2011*

**Structural Design, Part 2**

The structural technique that includes long vertical studs running from the sill plate to the second floor roof frame is called Frame
*January 20, 2011*

**calculus**

An athlete is running around a circular track of radius 50 meters at the rate of 5 meters per second. A spectator is 200 meters from the center of the track. How fast is the distance between the two changing when the runner is approaching the spectator and the distance between...
*January 11, 2011*

**world history**

The key diplomatic achievement of Bismarck's foreign policy was
*January 10, 2011*

**chemistry**

I am very confused about hybridization in general. Please give an explanation on how to do this. Which of the following pairs of atomic orbitals of adjacent nuclei can overlap to form a sigma bond? a pi bond? or no bond at all? a) 1s and 1s b) 1s and 2px c) 2px and 2py d) 3py ...
*January 8, 2011*

**chemistry**

freezin point of the solution 25.5g c7h11no7s in 1 x 100gh2O (nonionizing solute)
*January 6, 2011*

**math (combination)**

Hmm...the book says it's 252, which corresponds to (2C1)(9C4) or 252.
*December 30, 2010*

**math (combination)**

A woman has 11 close Friend. Find the number of ways she can invite 5 of them to dinner if a. but where 2 of the friends are married and will not attend seperately b. where 2 of the friend will not attend together the answer to a. 210 b. 252 Please explain....
*December 30, 2010*

**Math (combination/permutation)**

Let A denote one of the students. There are C(11,3) = 165 ways to choose 3 other students to be on the same tam as A. Now let B a student who is not on the same as A. Then let B be a studnt who is not on teh same team as A. There are C(7,3) = 35 ways to choose 3 from the ...
*December 30, 2010*

**Math (combination/permutation)**

Question 1: There are 12 students in a class. Find the number of ways that 12 studenets can take 3 different tests if 4 students are to take each test. Question 2 Find the number of ways 12 students can be partitioned into 3 teams A, B, C, so that each team contain 4 students...
*December 30, 2010*

**Math (combination/permutation)**

Question 1: There are 12 students in a class. Find the number of ways that 12 studenets can take 3 different tests if 4 students are to take each test. Question 2 Find the number of ways 12 students can be partitioned into 3 teams A, B, C, so that each team contain 4 students...
*December 30, 2010*

**SCI !!!!**

I love the poem! You did a great job!
*December 29, 2010*

**Chemistry**

A quantity of 0.020 mole of a gas initially at 0.050 L and 20 degrees Celsius undergoes a constant-temperature expansion until its volume is 0.59 L. Calculate the work done (in joules) by the the gas if it expands (b) pressure of 0.20 atm. (C) If gas in (b) is allowed to ...
*December 28, 2010*

**math**

the distance of D in feet it takes a car traveling at x mph to come to a full stop after hitting the brakes is given by d= 1.26x^2+ .075x. Est. the stopping distance for a car traveling at 40 mph
*December 17, 2010*

**ALGEBRA**

that is what I got
*December 13, 2010*

**ALGEBRA/please help**

-4(-25-(6)) -4 (-25-6) -4 (-31) 124
*December 13, 2010*

**math**

The volume of a ball is 288 pi cm^3. Find the dimensions of a rectangular box that is just large enough to hold the ball. use 3.14 for pie
*December 13, 2010*

**Chemistry**

The melting point of aspirin : 128-137Celsius degree. The melting point of the crude aspirin was measured to be 128 Celsius degree. What does it indicate about the purity of the product?
*December 5, 2010*

**Physics**

m*(L+Delta L)*w^2=k*(Delta L) Delta L=(m*w^2)/(k-m*w^2) Mass: 156 g=.156kg Answer: 0.128
*December 3, 2010*

**world history**

how did the Aztec and the Inca built their empires/
*December 1, 2010*

**calculus**

thank you
*November 23, 2010*