Thursday

September 29, 2016
Total # Posts: 567

**Physics**

Trying to be on time for class, a girl moves at 2.4 m/s down a 52 m-long hallway, 1.2 m/s down a much more crowded hallway that is 79 m long, and the last 25 m to her class at 3.4 m/s. How long does it take her to reach her class?

*September 18, 2012*

**simplify expression.**

|7|+|-14|

*September 17, 2012*

**math**

81 boys and 81 girls

*August 23, 2012*

**chemistry**

_mg(OH)†? + _H2SO4._mgSO4 + _H2O

*August 21, 2012*

**Trigonometry**

Find the exact value of tan2(Beta) if sin(Beta) = 5/13 (Beta in Quadrant II)

*August 12, 2012*

**Trigonometry**

Write 2sin37(degrees)sin26(Degrees) as a sum (or difference)

*August 12, 2012*

**Calculus**

Find the centroid of the area bounded by the parabola y = 4 - x^2 and the x-axis. A. (0,1.6) B. (0,1.7) C. (0,1.8) D. (0,1.9) Find the average value of the function i=15(1-3^-1/2t) from t=0 to t=4. A. 7.5(1+e^-2) B. 7.5(2+e^-2) C. 7.5(2-e^-2) D. 7.5(3-e^-2)

*August 7, 2012*

**Calculus**

evaluate (integral) xe^2x dx A. 1/6x^2 e^3x+C B. 1/2xe^2x-1/2e^2x+C C. 1/2xe^2x-1/4e^2x+C D. 1/2x^2-1/8e^4x+C Evaluate (integral) e^3x cosh 2x dx A. 1/2e^5x + 1/2e^x +C B. 1/10e^5x + 1/2e^x + C C. 1/4e^3x + 1/2x + C D. 1/10e^5x + 1/5x + C

*August 7, 2012*

**Calculus**

to evaluate (integral) 3x^2 cos (2x^3-4) dx, it is necessary to let A. u=3x^2 B. u=6x C. u=2x^3-4 D. u=6x^2

*August 4, 2012*

**Calculus**

Which of the following is a step in evaluating. (Integral) cos^2 5x dx A. (Integral) 1+cos10x/2 dx B. (Integral) 1-cos10x/2 dx C. (Integral) 1+cos10x/20 dx D. (Integral) 1-cos10x/20 dx

*August 4, 2012*

**Calculus**

Evaluate (integral) e^3x dx. A. e^3x + C B. 1/3e^3x + C C. e^4x + C D. 1/4e^4x + C

*August 4, 2012*

**Calculus**

Evaluate (Integral) sin 4x cos^2 4x dx. A. Cos^3(4x)/3 + C B. -Cos^3(4x)/3 + C C. Cos^3(4x)/12 + C D. -Cos^3(4x)/12 + C

*August 4, 2012*

**Calculus**

Evaluate (integral) cot 2x dx. A. 1/2Ln sin 2x+C B. 1/2Ln cos 2x+C C. 1/2Ln sec 2x+C D. 1/2LN csc 2x+C

*August 4, 2012*

**science**

how does the musculoskeletal system change from birth to adulthood to achieve 206 bones?

*August 4, 2012*

**Trigonometry**

Write 2sin37(degrees)sin26(Degrees) as a sum (or difference)

*August 3, 2012*

**Trigonometry**

Prove that tan (Beta) sin (Beta) + cos (Beta) = sec (Beta) Please explain.

*August 3, 2012*

**Trigonometry**

Prove that tan^2(alpha)-1+cos^2(alpha)sin^2(alpha) Please Explain

*August 3, 2012*

**Trigonometry**

* Solve tan^2x + tanx-1=0 for the principal value(s) to two decimal places.

*August 3, 2012*

**Trigonometry**

Solve tan2 x + tan x – 1 = 0 for the principal value(s) to two decimal places. Please Explain

*August 3, 2012*

**Trigonometry**

Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. Please explain.

*August 3, 2012*

**algebra**

find the total number of feet of wood needed if the trellis is 8 feet tall and 2 feet wide.

*August 1, 2012*

**math**

How to find the reciprocal of 5/3?

*June 30, 2012*

**math**

How do you find the reciprocal of 5/3

*June 30, 2012*

**psychology 240**

Factors that Determine What, When, and How Much We Eat, in the text, does your personal experience support these concepts? Why or why not? Provide examples

*June 25, 2012*

**language**

What's the noun and verb in seek his will in all you do and he will direct your path.

*June 19, 2012*

**chemistry**

A weather balloon if it starts with 10 liters of helium at 0km elevation and a temperature of 20 degrees. it is released and rises up through the atmosphere to an elevation of 12km where the temperature is -60degrees. calculate the volume of the helium at 12km.

*June 3, 2012*

**Calculus**

Use the given equation to answer the following questions. (Enter your answers from smallest to largest.) r = 8cos(¦È) 0 ¡Ü ¦È < ¦Ð (a) Find the points on the given curve where the tangent line is horizontal. theta= theta= (b...

*June 1, 2012*

**Math**

Carole earns 2.50 for each gadget she completes, what was her gross pay if she completed 145 gadgets last week.

*May 27, 2012*

**Pre calculus**

How do you work this problem? Find the exact value of sin 2u, cos 2u, and tan 2u given that cot u=3 and 180<u<270

*May 14, 2012*

**health**

Which age groups benefit from physical activity? A. Children B. Middle aged adults C. Older adults D. All of the above

*April 24, 2012*

**MATH**

What percentage of scores falls between +1 and +2 standard deviations?

*April 3, 2012*

**health**

What is a medical scientist,if you want to study medical science,what are the minimum requirements?and how can you briefly describe medical science?

*March 15, 2012*

**Physics**

A box rests on the back of a truck. The coefficient of static friction between box and bed of the truck is 0.255. (a) When the truck accelerates forward, what force accelerates the box? A)the inertial force B)gravity C)centripetal force D)the friction force (b) Find the ...

*March 8, 2012*

**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*

**sacred heart high school **

don't know

*August 28, 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*

**why do you think communication is vital to the success of every business organization**

Not answered

*July 26, 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*