Tuesday

October 21, 2014

October 21, 2014

Total # Posts: 659

**Chemistry **

If the minimum (threshold) energy for the emission of an electron from the surface of a particular metal is 3.90 X 10-19 J, what is the kinetic energy of an electron emitted from the surface of the metal when it is irradiated by electromagnetic radiation of wavelength 213 ...
*October 10, 2014*

**Chemistry **

What amount of energy is required to melt a 27.4 g piece of ice at 0oC? The heat of fusion of ice = 333 Jg-1 Heat required to melt the ice 9.12e3 = J What amount of energy must be removed from 123 g of water to cool it from 71.6oC to 9.41oC? Specific heat of water = 4.184 JK-...
*October 2, 2014*

**physics**

A book of mass 7 kg rests on a plank. You tilt one end of the plank and slowly increase the angle of the tilt. The coefficient of static friction between the book and the plank is 0.40. What is the maximum angle of tilt for which the book will remain stationary and not slide ...
*September 24, 2014*

**physics**

A flatbed truck is supported by its four drive wheels, and is moving with an acceleration of 7.4 m/s2. For what value of the coefficient of static friction between the truck bed and a cabinet will the cabinet slip along the bed surface?
*September 24, 2014*

**Statistics**

The Graduate Record Examination (GRE) has a combined verbal and quantitative mean of 1000 and a standard deviation of 200. Scores range from 200 to 1600 and are approximately normally distributed. For each of the following problems: 1. Draw a rough sketch, darkening the ...
*September 22, 2014*

**writing**

Bing (common search engine) iSEEK Education (academic search engine) MetaLib metasearch engine) ( What types of information did each search provide? Discuss what features you like and dislike about each of the search engines.
*September 18, 2014*

**information literacy**

.Why do we need information? What sources do you already use to obtain personal information
*September 14, 2014*

**Chemistry**

Name the property that each change depends on. Then classify the property as either chemical or physical. a) You separate a mixture of gravel and road salt by adding water to it b) Carbon dioxide gas freezes at a temperature of -78C
*September 8, 2014*

**Psychology**

1) Your companion is in favor of staying hidden and simply watching the tribe so that you can understand how they live. You feel however that you could better understand how they live (and how to SURVIVE!) if you make your presence know and join the tribe. What kinds of ...
*September 1, 2014*

**trigonometry**

graph y=-3sec(2x-pi/3)proved the period vertical translation and the phase shift
*July 22, 2014*

**finance**

What is the payback period of the following project? Initial Investment: $50,000 Projected life: 8 years Net cash flows each year: $10,000
*July 19, 2014*

**Microeconomics**

Correcting for negative externalities - Regulation versus tradablepermits Suppose the government wants to reduce the total pollution emitted by three local firms. Currently, each firm is creating 4 units of pollution in the area, for a total of 12 pollution units. If the ...
*May 29, 2014*

**Finance**

What is the present value of $3,800 at 8.9 percent compounded monthly for five years. Thurs far, I have P= ?/(1+i)n (1 + 0.89/12)12*5 (1.0074167)60
*May 12, 2014*

**Mathematics**

I need help finding the exact value of sin (a + b), given that sin a =3/5 and sin b = 5/13, with a in quad 2 and b in quad 1.
*May 9, 2014*

**chemistry**

Calculate the amount of CO2 formed when 50 grams of CaCO3 decomposes?
*May 2, 2014*

**math **

4 red,5 blue,1 yellow marble Find the probability of picking a red marble then not replacing it and then drawing a blue marble. answer as a fraction,decimal and percent.
*April 20, 2014*

**math**

how many ways can 10 runners finish a race. 10 could finish 10 9 could finish 9 and so on would I times 10*9*8 ect that number seems way to big.
*April 20, 2014*

**5TH GRADE MATH**

Need help trying to tell my daughter what or how to draw this........ DRAW a figure composed of three different rectangles that has a perimeter of 140 yards. Use measurements that are in yards and feet to label the sides of your figure......
*April 16, 2014*

**math**

Thank you I was trying to over think that problem.
*April 13, 2014*

**math**

Sue has a list of 8 CDs and 5 DVDs that she wants to buy. Her friends randomly select one item to give her. What is the probability Sue's friend will select a CD? a DVD?
*April 13, 2014*

**statistics**

A large number of applicants for admission to graduate study in business are given an aptitude test with a resulting mean score of 460 with a standard deviation of 80. The top 2.5 percent of the applicants would have a score of at what? A. 606 B. 617 C. 600 D. 646
*April 11, 2014*

**math**

The height of a soccer ball that is kicked from the ground can be approximated by the function y=-16x^2 +32x where y is the height of the soccer ball on feet x seconds after it is kicked. Graph this function. find the soccer balls maximum height, and the time it takes the ...
*April 9, 2014*

**math**

Have to write the number would it be 505200000000000
*April 7, 2014*

**math**

5.052 x 10^14
*April 7, 2014*

**math**

what is -8 squared +(17 - 9)x 4 + 7
*March 26, 2014*

**chem**

at a certain temperature, .700 mol of SO3 is place in a 4.50-L container. 2SO3(g)--2SO2(g)+O2(g) At equilibrium, .140 mol of O2 is present. Calculate Kc
*March 14, 2014*

**Chemistry**

What is the minimum amount of 5.9M H2SO4 necessary to produce 27.7g of H2 (g) according to the following reaction? 2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H2(g)
*March 5, 2014*

**physics**

A uranium nucleus (mass 238 u), initially at rest, undergoes radioactive decay. After an alpha particle (mass 4.0 u) is emitted, the remaining nucleus is thorium (mass 234 u). If the alpha particle is moving at 0.055 the speed of light, what is the recoil speed of the thorium ...
*March 3, 2014*

**History**

Anti-catholic sentence erupted in Maryland when in 1689, news arrived of the deposition of
*March 1, 2014*

**Math**

x-1=4 2/3
*February 18, 2014*

**math**

in a department sore there are red t-shirts, blue t-shirts, and yellow t-shirts. 3/7 of the shirts are red, 1/3 are blue and the rest are yellow. if there were 20 more red than blue, how many were yellow?
*February 6, 2014*

**math**

amamda is 12 years old. she is 2/7 times as old as her father. how many years ago was her father 4 times as old as amanda?
*February 6, 2014*

**accounting**

don't know
*February 4, 2014*

**URGENT: Please help with Physics**

Suppose the mass of each of two spherical objects is doubled, and the distance between their centers is three times as large. How is the magnitude of the force of gravity between them affected? (Points : 5) It is 4/9 as large. It is 4/3 as large. It is 2/9 as large. It is 3/2...
*January 15, 2014*

**PHYSICS, please help quickly**

Thank you for your help
*January 15, 2014*

**PHYSICS, please help quickly**

The velocity of an object increases from 5.0 m/s to 15 m/s in 2.0 s. What is the average acceleration of the object? -10 m/s2 -5.0 m/s2 +5.0 m/s2 +10 m/s2
*January 15, 2014*

**Math, please help**

Which of the following are trigonometric identities? (Can be more then one answer) tanx cosx cscx = 1 secx-cosx/secs=sin^2x 1-tanxtany=cos(x+y)/cosxcosy 4cosx sinx = 2cosx + 1 - 2sinx Find all solutions to the equation cosx cos(3x) - sinx sin(3x) = 0 on the interval [0,2π...
*January 14, 2014*

**Math Check 2 ?s quick**

Thank you so much!
*January 14, 2014*

**math**

A choir is singing at a festival. On the first night 12 choir members were absent,so the choir stood in 5 equal rows. On the second night only one member was absent, so they stood in 6 equal rows. the same number of people stood in each row each night. How many members are in ...
*January 14, 2014*

**Math - Algebra**

Four digit number. Greater than 4000. Sum of its hundreds digit and it's ones digit is 9. Twice it's tens digit is 2 more than its thousands digit. Sum of one- fifth of its hundreds digit and two-thirds of its ones digit is 6. It's 10 digit is 1 less than its ...
*January 4, 2014*

**social studies**

would military spending be a modern example of a centrally planned economic system
*December 15, 2013*

**math**

Members of the Campus Roller Rink pay a yearly membership fee of $50 plus $5 each time they go skating. nonmembers pay $10 each time the go skating. How many times would both members and nonmembers have to go skating in a year in order to pay the same amount?
*November 7, 2013*

**math**

5/8a+6=3/4a 6=1/8a a=6/8 is this correct? thank you.
*November 7, 2013*

**algerbra**

Keisha read twice as many books this year as ben read. subtracting 4 from the number of books Keisha read and dividing by 2 gives the number of books Sheldon read. Sheldon read 10 books. How many books did Ben read?
*November 4, 2013*

**Physics**

the incline is 30 degrees
*November 3, 2013*

**Physics**

A car starts rolling down a l-in-4 hill (l-in-4 means that for each 4 m traveled along the road, the elevation change is 1 m). How fast is it going when it reaches the bottom after traveling 55 m? (a) Ignore friction, (b) Assume an effective coefficient of friction equal to 0....
*November 3, 2013*

**Physics**

agent dave, flying a constant 215 km/hr horizontally in a low - flying helicopter wants to drop a small explosive onto a master criminal automobile travelling 155km/hr on a level highway 78m below. At what angle (with the horizontal) should the car be in his sights when the ...
*October 22, 2013*

**Physics**

agent dave, flying a constant 215 km/hr horizontally in a low - flying helicopter wants to drop a small explosive onto a master criminal automobile travelling 155km/hr on a level highway 78m below. At what angle (with the horizontal) should the car be in his sights when the ...
*October 22, 2013*

**algebra**

A video store charges a monthly fee of 7.50, but the charge to rent each movie is only 1.00 per movie. Another store has no membership fee, but it costs 2.50 to rent each movie. How many movies need to be rented each month for the total fees to be the same from either company?
*October 1, 2013*

**algebra**

2/8=x+2/72
*October 1, 2013*

**math**

how many Km are in 1000dm?
*September 30, 2013*

**Pysch**

______is to biological factors as ___________ is to cultural factors? a. Race; ethnicity b. nurture; diversity c. Individualism; collectivism d. Ethnicity; race
*September 15, 2013*

**Science**

arrange the following aqueous solutionsin order of increasing freezing points(lowest to highest temperature): 0/10m glucose, 0.10m BaCl2, 0.20mNaCl, and 0.20m Na2SO4.
*September 11, 2013*

**history**

Thank you Ms Sue
*September 8, 2013*

**history**

The perioeci and helots revolted against which city-state? In the golden age of Greece an Athenian worked in the morning and did what in the afternoon?
*September 8, 2013*

**physics**

You are driving a car 35mi/h down the road. The stoplight in front of you suddenly turns red and you slam on the brakes, skidding to a halt. You get out of the car and measure the skid marks made by your tires to be 28.5m meters. (Assume positive x to be in the forward ...
*September 1, 2013*

**math**

write the algebraic expression the quotient of 100 and the quantity6 plus w (6+w)/100 the quotient of 23 and u minus t 23/u-t would these be correct?
*August 22, 2013*

**what you read**

what word in the sentence is most clearly a loaded word?
*August 14, 2013*

**chemistry**

Barium carbonate and nitric acid: BaCO3 (s) + 2HNO3 (aq.) --> Ba2+ (aq.) + 2(NO3-) (aq.) + CO2 (g) + H2O (l) If 25.0mLs of 0.150M nitric acid was used, how many grams of barium carbonate would be required for complete reaction?
*July 2, 2013*

**chemistry**

Using the equipment below, explain how to prepare a 0.00052M HCl solution from a reagent bottle containing 0.13M HCl using only the equipment listed below. Note, you may make multiple dilutions, but you are not allowed to combine volumes. For example, if you need 2 mLs of a ...
*July 2, 2013*

**Physics**

a 3.6 kg object is accelerated from rest to a speed of 34.4 m/s in 42 s. What average force was exerted on the object during this period of acceleration. Answer in units of N.
*June 30, 2013*

**Physics**

Consider a coin which is tossed straight up into the air. After it is released it moves upward, reaches its highest point and falls back down again. Air resistance can be neglected. What force acts upon the coin while it moves upward after it is released? a. Force of zero b. ...
*June 30, 2013*

**chemisty**

calculate the heat energy released when 25.8 g of liquid mercury at 25 C is converted to solid mercury at its melting point. Constants for mercury at 1 atm: heat capacity of Hg-->28.0 melting point-->234.32 K enthalpy of fusion-->2.29 kj/mol
*June 27, 2013*

**chemistry**

Two 20.0 g ice cubes at -16.0 C are placed into 285 g of water at 25.0 C. Assuming no energy is transferred to or from the surroundings, calculate the final temperature of the water after all the ice melts. heat capacity of H2o(s)-->37.7 heat capacity of H2o()-->75.3 ...
*June 27, 2013*

**chemistry**

Calcium oxide and carbon are reacted to produce carbon monoxide and calcium carbide CaC2. When one mole of calcium carbide is formed, 464.8kJ is absorbed. How many grams of carbon are used up when 20.00kJ of heat is absorbed?
*June 22, 2013*

**chemistry**

Calcium oxide and carbon are reacted to produce carbon monoxide and calcium carbide CaC2. When one mole of calcium carbide is formed, 464.8kJ is absorbed. What is the enthlapy of reaction when 1.00g of calcium carbide is formed?
*June 22, 2013*

**chemistry**

Calcium oxide and carbon are reacted to produce carbon monoxide and calcium carbide CaC2. When one mole of calcium carbide is formed, 464.8kJ is absorbed. Write a thermochemical equation for this reaction.
*June 22, 2013*

**economics**

Am i right, just checking as too many wrong homework assignments at the start of this semester have messed up my grades If the required reserve ratio is 0.2, by how much could the money supply expand if the central bank purchased £2 billion worth of bonds? 2.0 billion x ...
*May 24, 2013*

**economics**

oops should be in $ not £, eek!
*May 22, 2013*

**economics**

am i right? dont want to hand in wrong homework again, my mom will kill me A research firm calculated that students who attend University spend about $2,760 each in the local economy for a total of $50.45 million. In total, the impact of their spending on the local economy is...
*May 22, 2013*

**math**

you need to make a three dimensional model of a soup can using paper and tape. What 3 dimensional shapes do you need to cut ot make the model?
*April 30, 2013*

**math **

ms kim is assigning each student in her class one of the fifty us states on which to write a report. What is the probability that jan will be assigned one of the 5 states that has a coastline on the pacific ocean? express the probability ratio as a fraction and as a decimal
*April 28, 2013*

**math**

between 8pm and 9pm the station broadcasts 8 min of commercials. What is the ratio of commercial time to noncomercial time during the hour? would it be 13:15
*April 28, 2013*

**social studies**

they blth have three branches of goverment correct?
*April 24, 2013*

**social studies**

how is todays goverment similar to the goverment of the roman republic?
*April 24, 2013*

**social studies**

what is the largest climate region in north america?
*April 24, 2013*

**science**

What are the similarities between air masses and fronts?
*April 17, 2013*

**english**

what is the pronoun and antecedent in this sentence. Scientists have tried to teach sign language to chimps, but Kaatu could not learn it.
*April 15, 2013*

**Math**

The teams ratio of games won to games played was 9 to 11. If the team played 66 games, how many did the team win? Explain your answer.
*April 9, 2013*

**Algebra**

Use the given zero to find the remaining zeros of the function. f(x)=x^3-2x^2+9x-18;zero;3i Enter the remaining zeros of f =
*April 9, 2013*

**use the given zero**

Use the given zero to find the remaining zeros of the function. f(x)=x^3-2x^2+9x-18;zero;3i Enter the remaining zeros of f =
*April 9, 2013*

**rational zeros theorem**

Use the rational zeros theorem to find all the real zeros of the polynomial function. Use the zeros to factor f over the real numbers. f(x)=25x^4+26x^3+126x^2+130x+5 Find the real zeros x= Use the real zeros to factor f f(x)=
*April 9, 2013*

**Solve the polynomial inequality**

Thank you!!!
*April 9, 2013*

**Solve the polynomial inequality**

Solve the polynomial inequality and graph the solution set on a real number line. Express the solution set in interval notation. x^3+x^2+4x+4<0 The solution set is=
*April 9, 2013*

**math**

Considera compoound experment in which a nickel is flipped and then a quarter is flipped, need to know all the possible outcomes I came up with 4. correct? also need to know the probability of each possible outcome
*April 8, 2013*

**math**

I used 8 gallons of gas when I drove for 240 miles. How many gallons of gas are needed to drive 720 miles??
*April 6, 2013*

**physics**

A sled is accelerating down a hill at a rate of 1 m/s2 . If the mass of the sled is suddenly cut in half and the net force on the sled is doubled, what is the acceleration of the sled?
*April 4, 2013*

**math**

a family walked 15 miles in one day . at that rate how many would they travel in 5 days? make a table to show your work
*April 4, 2013*

**Chemistry**

I guess I am still stuck on problem a. I know I have to calculate Ka from Kb in order to calculate pH. When I do that, I get a pH over 14 which cannot be. What am I doing wrong?
*April 1, 2013*

**Chemistry**

use the Hendeson-Hasselbalch equatio. To calculator the pH of a solution at is A) 0.15 M on C5H5N and 0.10M in C5H5NHCl. Kb:1.7x10^-9 B) 15.0 g of HF and 25.0g of NaFin 125 ml of a solution. Ka 3.5x10^-4
*April 1, 2013*

**Chemistry**

Here is what I got : a) formation of a buffer solution B) strong acid and strong base, no formation of a buffer solution. C) formation of a buffer solution D) strong acid and weak base, formation of a buffer. Am I correct? thank you
*April 1, 2013*

**Chemistry**

Explain clearly which out of the following combinations of solutes would result in the formation of a buffer solution? A) NH3 and HCl in a 2:1 molar ratio B) HCl and NaOH in a 1:2 molar ratio C) NH3 and NH4Cl in a 2:1 molar ratio D) NaOH and CH3COOH in a 1:1 molar ratio And: ...
*April 1, 2013*

**Math**

I am a number with a multiple of 10, largest digit is in the tens place, and sum of the digits is 3.
*March 25, 2013*

**Chemistry**

Sorry typo..it's NaF and it doesn't say how much was added that's the question given
*March 22, 2013*

**Chemistry**

Calculate the pH of a solution that is 2.00M HF, 1.00M NaOH, and 0.393M NaG (Ka=7.2 x10^-4). The answer I got was 4.76 ..
*March 22, 2013*

**Chemistry**

what is the pH of a solution prepared by adding 0.259g of ammonium chloride to 115mL of water? Kb of NH3 is 1.8x10^-5
*March 22, 2013*

**Stats**

1. The question asks to choose a data point in our graph (we chose 476,44) of median home prices (x) and percentage of students who scored Advanced on math MCAS (y). We have to find the residual. I'm confused because the equation I was given is e=y-yhat I know one is the ...
*March 19, 2013*

**Stats**

1. The question asks to choose a data point in our graph (we chose 476,44) of median home prices (x) and percentage of students who scored Advanced on math MCAS (y). We have to find the residual. I'm confused because the equation I was given is e=y-yhat I know one is the ...
*March 18, 2013*

**math**

Thank you for the help Ms Sue you put me on the right track to figure out the question
*March 17, 2013*

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