Thursday

July 31, 2014

July 31, 2014

Total # Posts: 6,202

**CHEMISTRY**

A mixture of Xe, Kr, and Ar has a total pressure of 6.7 atm. What is the mole fraction of Kr if the partial pressures of XE and Ar are 1.6 atm and 2.8 atm? Did anyone get .343 ?

**composition(paraphrase this paragraph)**

Much of the gap between the schooling of orphans and non-orphans is explained by the greater tendency of orphans to live with more distant relatives or unrelated caregivers.

**statistics**

Suppose that 98% of your customers in your market have internet access and you select a random sample of 500 customers. What is the standard error of the proportion of customers who don’t have internet access? I seem to be struggling with no standard deviation listed

**english**

Please read the following excerpt from an essay, and answer the question that follows. Biologically, adolescence is marked by hormonal changes that produce secondary sexual characteristics. These include breast development in females and beard growth in males. (Psychologically...

**Statistics**

Compute a one-way ANOVA - Give the source table, test null hypothesis at .05 level. Please explain the steps to solving this. Group 1: 26, 34, 46, 48, 42, 49, 74, 61, 51, 53 EX 1 : 484 Ex 1^2 : 25,024 n = 10 Group 2: 51, 50, 33, 28, 47, 50, 48, 60, 71, 42 EX 2 : 480 EX 2^2 : 2...

**math**

which equation = (1,1)and(0,-1)and (-2,-5) A.y=2x-1 orB.y=x-1 0r C.y=2x+1 or D. y=x+1

**Chestry**

Yes chemistry

**Chestry**

If there are 8.8 moles of h2 and co2 in a 500 ml container at equilibrium how many moles of co and h2o would be present?

**english**

i have to do an english presentaion for my grade 12 class about a book that i was assigned, how can i involve the class in my presentation?, the book i had to read is called "fall on your knees"

**math**

oh didnt see the the last sentence

**math**

7 hours

**math**

A telephone pole casts a shadow 16 feet long at the same time that a man 6 feet tall casts a shadow of 2.4 feet. How tall is the pole?

**Algebra**

120 meters of fencing is used to fence 3 sides of a dog park against an existing wall. if the width of the park is w, find the length of the field in terms of w

**physics**

during a process, 21.6 MJ of heat is added to closed system. if the internal energy is increased by 59.6 MJ, how much work in Btu was done? is the work done on ro by the system?

**algebra 2**

by gruoping...!!

**phi 103**

I brought a pair of shoes from that store that immediately fell apart. their shoes are no good. Does this falls under Begging the question fallacy?

**Chemistry!!**

1) Write balanced chemical equation for the oxidation of Fe^2+(aq) by S2O6^2-(aq)? 2)Write balanced chemical equation for the oxidation of Fe^2+ by N2O 3)Write balanced chemical equation for the oxidation of Fe^2+ by VO2+

**math**

Solve this system using elimination. If a single solution exists, write the solution as an ordered pair. Your answer will be an ordered pair, no solution, or infinitely many solutions 3a+5b=-19 5a-27b=145

**English II - Animal Farm**

My assignment is to find the human vice that each of the seven commandments intended to prevent in the novel, Animal Farm. First, I do not know what human vice the following two are supposed to prevent: Whatever goes upon two legs is an enemy. Whatever goes upon four legs, or ...

**math**

how long will $600K last, assuming it earns 6% a year with a withdrawl of 4% annually and inflation rate of 2%

**math**

Name the point of intersection for the following system, if it exists. Your answer will be an ordered pair, no solution, or infinitely many solutions. 4x-3y=-3 3x-y=-6

**PHYSICS**

a uniform stick weighing 50Newton is suspended from the ceiling while the other end of it rests on the floor and making an angle 60degree along with horizontal. the string makes a 15 degree angle with the vertical. find the minimum value of the coefficient of static friction t...

**physics**

a person 0f mass m = 60 kg walks along the radius from the periphery to the center of a circular platform of moment of inertia= 200kgm square and radius r = 3m. the disk is a rotating frictionless with angular velocity= 0.3 rad\s.find the angular velocity of the system when th...

**Chem**

If 20.0 L of a gas is cooled from 373 K to 273K, what is the new volume?

**english**

hey I'm a 9th grader and my english teacher give me a summative homework about rumors. He need us to write a problem that happen in school and also want us to answer or solve the problem about rumors.. I need help with it because I know nothing about rumors..

**math**

Name the point of intersection for the following system, if it exists. 4x – 3y = -3 3x – y = -6

**@elena**

nvm, i did it wrong. i already got the answer its 79% thanks

**@elena**

thank you so much help with the problem. i have trouble solving part b of the problem you helped me with. it told me to give it as a percentage, I got 10% but it is wrong. can you please help me Superman must stop a 190-km/h train in 180m to keep it from hitting a stalled car ...

**college physics**

i got it its 79% i was label some of the numbers with the wrong variables. tahnks and will keep that in mind

**@elena Question !**

for part b, what would be the percentage. i got 10% but it isnt right

**college physics**

Superman must stop a 190-km/h train in 180m to keep it from hitting a stalled car on the tracks. part a)If the train's mass is 3.8×10^5kg , how much force must he exert (find the magnitude)? part b)Compare to the weight of the train (give as %). partc) How much force...

**uniben**

do it urself

**math**

expand as a binomial series (r-p)^9

**math**

An exam consists of two parts, Section X and Section Y. There can be a maximum of 80 questions. There must be at least 20 more questions in Section Y than in Section X. Write a system of inequalities to model the number of questions in each of the two sections. Then solve the ...

**math**

When a person is swinging the amplitude (the swings"s distance above it's rest position) increases with each pump. According to Scientific magazine the amplitude increases by adding a constant when the person pumps sitting down, and by multiplying by a constant when t...

**chemistry**

(ppm and ppb are sooo not easy for me to get)c A saturated solution of PbCO3 contains 0.00011 g PbCO3 in 100. g of water. What is this concentration in parts per million?

**chemistry**

Most community water supplies have 0.50 ppm of chlorine added for purification. What mass of chlorine must be added to 134.0 L of water to achieve this level? anwser grams

**chemistry**

A sample of water is analyzed and found to contain 18.6 ppb of arsenic. If a person were to drink 2.0 L of this water per day for 1.4 years, what is the maximum amount of arsenic they could accumulate in their body? Assume that 1 year = 365 days anwser________ grams or arsenic

**biology **

1,Why do autotrophs always occupy the lowest level of ecological pyramids? 2.Explain how the growth of one population can bring about the disappearance of another population during succession? 3. Describe some common plants and animals from a tropical rain forest and a grassla...

**chemistry**

4NH3(g)+5O2(g) yield 4NO(g)+6H2O(g) Deduce the equilibrium constant expression for the reaction.

**Chemistry**

A 2.7 M solution of phosphoric acid (H3PO4) is to be reacted with a 7.5 M solution of sodium hydroxide to make sodium phosphate and water. How many L of the H3PO4 solution will react with 0.662 L of the NaOH solution

**life orintation**

8 ways in which the environment impacts communities

**Mechanics problem - Newtons laws - resultant force**

I have this mechanics problem. Please help me solve it. Rory, Aurora and Raoul are three lions fi ghting over a piece of meat of mass 12 kg. Each lion exerts a horizontal pull. Rory pulls with a force of 800 N. Aurora, who is 120degrees to Rory's right, exerts a force of 4...

**l.o**

identify and describe one environmental proble that causes ill health,accidents,crises,and disasters within your community or any other community within south africa or globally

**calculis**

Find the equation of the tangent line to the curve y=e^2x + 4x at the point (0,1)

**calculus**

Find the equation of the tangent line to the curve y=e^2x + 4x at the point (0,1)

**math**

a cubical container is half filled with water if the volume of water in the container is 500cm3 find the length of one edge of container?

**math**

a rectangular tank has the measurement 60cm wide and 2000cm2 water flows into the tank at the rate of 8 liters per minutes how long will it take to fill the tank?

**math**

a rectangular swimming pool is 30m wide and 50m long if the 600m of water is added to the pool what is the increase in the height of the water level in centimeters?

**math**

A rectangular box is 16cm long and 10cm wide 960 1-cm cubes can fit into the box exactly what is the height of the box?

**Physics**

Anyone else from SF have to google this question, or was i the only one?

**pre-calc helpppp**

Find sin x/2, cos x/2, and tan x/2 from the given information. (show work please) thank you!!! cos x = − 4/5, 180° < x < 270°

**pre-calc helpppp**

thank you so much!!!!

**pre-calc helpppp**

Simplify the expression by using a Double-Angle Formula or a Half-Angle Formula. ã((1-cos50)/2)

**pre-calc helpppp**

Thank you!!!!

**pre-calc helpppp**

Evaluate the expression under the given conditions (show steps please) sin(è/2); tan è = − 5 / 12 , è in Quadrant IV

**Chemistry!! Help**

Consider the following equilibrium: N2O4 <=> 2NO2 You may assume that delta H and delta S do not vary with temperature. At what temperature will an equilibrium mixture of 1 atm total pressure contain twice as much NO2 as N2O4?

**Chemistry!!!**

Consider the rxn during the Haber Process: N2 + 3H2 ---> 2NH3 The equilibrium constant is 3.9 x 10^(5) at 300 K and 1.2 x 10^(-1) at 500 K. Find Delta H reaction and Delta S for reaction

**MATH##$$&&^^****

4.16%

**Physics**

Thanks Elena your a life saver :)

**Physics**

A cube of ice is taken from the freezer at -8.8°C and placed in a 103 g aluminum calorimeter filled with 321 g of water at room temperature of 20°C. The final situation is observed to be all water at 15°C. What was the mass of the ice cube? Could someone please hel...

**math**

6/8

**math**

The water in fish tank has evaporated so it was 5/8 inch below the level it should be they added water and the water level went up 3/4 inch did the water level end up above or below where it should be

**science**

Which of the following scales use the concept of absolute zero? I. C II. F III. K IV. R

**science**

Thermal energy is different from temperature because thermal energy depends on the _____.

**science**

A trash can is rolling down the street at 5 m/s. If the trash can has a mass of 23 kg, what is its momentum?

**chem**

Brandon throws a flying disc with a force of 8 N. If the disc has an acceleration of 4 m/s2, what is the mass of the disc?

**science**

Brandon throws a flying disc with a force of 8 N. If the disc has an acceleration of 4 m/s2, what is the mass of the disc?

**english**

thank you and for this one: Meredith is to be restored as captain.the infinitive is to be and is a noun?

**english**

so it is to use and it would be a adverb

**english**

okay and the second one is i have permission and its a adverb?

**english**

okay and the answer can only be a noun.adverb or adjective.

**english**

i have one more question what is the function of the italicized infinitive phrase ins the sentence. 1.I want to go with you to the store. 2.May I have permission to use the car tonight?

**english**

thank you ms.sue

**english**

what is the gerund phrase and the noun function of the gerund in the sentence 1.Her favorite pastime is entertaining friends.

**Math**

A math teacher is randomly distributing 15 rulers with centimeter labels and 10 rulers without centimeter labels. What is the probability that the first ruler she hands out will have centimeter labels and the second ruler will not have labels.

**physics- help please !!1**

A toy rocket moving vertically upward passes by a 2.2m -high window whose sill is 7.0m above the ground. The rocket takes 0.17s to travel the 2.2m height of the window part a) what was the launch speed of the rocker ? assume the propellant is burned very quickly at blastoff pa...

**physics**

15.5

**Chemistry 1201**

Thanks so much!

**Chemistry 1201**

Butane, C4H10, is a component of natural gas that is used as fuel for cigarette lighters. The balanced equation of the complete combustion of butane is 2C4H10(g)+13O(g)-> 8CO2(g)+10H2O(l) At 1.00 atm and 23C , what is the volume of carbon dioxide formed by the combustion of...

**Chemistry 1201**

Butane, C4H10, is a component of natural gas that is used as fuel for cigarette lighters. The balanced equation of the complete combustion of butane is 2C4H10(g)+13O(g)-> 8CO2(g)+10H2O(l) At 1.00 atm and 23C , what is the volume of carbon dioxide formed by the combustion of...

**Chemistry 1201**

When heated, calcium carbonate decomposes to yield calcium oxide and carbon dioxide gas via the reaction CaCO3(s)->CaO(s)+CO2(g) What is the mass of calcium carbonate needed to produce 53 L of carbon dioxide at STP?

**Pre-Calc Help!!!!!!!!!!!!!!!!1**

can someone help me please????

**Calc Help!!!!!!!!!!!!!!!!1**

tan(sin^-1(5/6)-cos^-1(1/5)

**Math**

Try 868

**physics**

An athlete thtrew a short put of mass7.52kg through a distance of 24m when we projected a short put at angle of 30. Assuming there is no air resistance, what is the initial kinetic energy of the athlete.

**psyc355**

30.9

**psyc355**

Children below the 30th percentile (in the bottom 30%) are in need of special assistance prior to attending school. What raw score marks the cut-off score for these children?

**Chemistry!!!**

What is the solubility of MnS, in grams per liter, in a buffer solution that is 0.120 M HC2H3O2 - 0.490 M NaC2H3O2? For MnS, Kspa=3x10^7.

**Chemistry!!**

A solution has [Al^3+]=8.0×10−2 M and [HC2H3O2]= 1.10 M. What is the maximum quantity of NaHC2H3O2 that can be added to 200.0 mL of this solution before precipitation of Al(OH)3 begins?

**Accounting**

At the beginning of April, Owl Corporation has a balance of $12,000 in the Retained Earnings account. During the month of April, Owl had the following external transactions. 1. Issue common stock for cash, $10,000. 2. Provide services to customers on account, $7,500. 3. Provid...

**physics**

Calculate the internal energy of 25.0 g of low-density oxygen gas (O2) at a temperature of 255 K.

**Physics**

a.) P=P initial + pgh 101,000 Pa + (1000)(9.8)(2.5) P=125500Pa. P=F/A 125500=F/50 6.3*10^6N

**Chem...**

1) what is the density of methane (CH4) at a temp. of 20C and a pressure of 684mm. 2) a gas has a density of 2.5g/L at a temp. of 20C and a pressure of 1.1 atm. what is its molar mass.

**Math**

As a fraction it is 60/100 but you probably need to simplify it so find a common factor of both, in this case the number 20, and divide both 60 and 100 by that to get the fraction of 3/5. 60% is equal to .6 because 100% equals 1.

**Physics**

The formula to use is c=f*lambda where c equals speed of a wave, f is frequency, and lambda is the Greek for wavelength. So to find the speed you multiply 9 by .654 and the answer should be 5.886 m/s.

**math**

I believe to find the sum of the exterior angles of a n-sided polygon is (n-2)*180 where n is the number of sides. So for a 50-sided polygon it should be 8640 degrees. For the interior angles it is (n-2)*180/n where again n is the number of sides.

**Math**

For a line to be perpendicular to another line you need to use m in the linear equation of y=mx+b and find the opposite and reciprocal of that number. In this case m is 3 so the opposite of 3 is -3 and the reciprocal is just flipping the fraction of -3/1 so it is now 1/-3. Now...

**Physics**

Where must an object be placed to have a magniﬁcation of 3.74 in front of a converging lens of focal length 14.1 cm? Answer in units of cm

**Science**

D because mechanical energy is basically kinetic energy and when that is greater than the force of gravity then it will not fall down.

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