Sunday

August 30, 2015
Total # Posts: 6,779

**uniben**

do it urself
*April 29, 2012*

**math**

expand as a binomial series (r-p)^9
*April 28, 2012*

**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 ...
*April 28, 2012*

**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 ...
*April 27, 2012*

**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?
*April 26, 2012*

**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
*April 26, 2012*

**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
*April 26, 2012*

**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 ...
*April 26, 2012*

**chemistry**

4NH3(g)+5O2(g) yield 4NO(g)+6H2O(g) Deduce the equilibrium constant expression for the reaction.
*April 26, 2012*

**Physics Please someone help please**

A 30 g glass thermometer reads 21.6°C before it is placed in 135 mL of water. When the water and thermometer come to equilibrium, the thermometer reads 38.1°C. What was the original temperature of the water? Please provide step by step equation and answer
*April 26, 2012*

**Physics Please someone help please**

A 30 g glass thermometer reads 21.6°C before it is placed in 135 mL of water. When the water and thermometer come to equilibrium, the thermometer reads 38.1°C. What was the original temperature of the water? Please provide step by step equation and answer
*April 26, 2012*

**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
*April 25, 2012*

**life orintation**

8 ways in which the environment impacts communities
*April 24, 2012*

**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 ...
*April 24, 2012*

**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
*April 23, 2012*

**calculis**

Find the equation of the tangent line to the curve y=e^2x + 4x at the point (0,1)
*April 23, 2012*

**calculus**

Find the equation of the tangent line to the curve y=e^2x + 4x at the point (0,1)
*April 23, 2012*

**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?
*April 23, 2012*

**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?
*April 23, 2012*

**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?
*April 23, 2012*

**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?
*April 23, 2012*

**Physics**

Anyone else from SF have to google this question, or was i the only one?
*April 22, 2012*

**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°
*April 21, 2012*

**pre-calc helpppp**

thank you so much!!!!
*April 21, 2012*

**pre-calc helpppp**

Simplify the expression by using a Double-Angle Formula or a Half-Angle Formula. ã((1-cos50)/2)
*April 21, 2012*

**pre-calc helpppp**

Thank you!!!!
*April 21, 2012*

**pre-calc helpppp**

Evaluate the expression under the given conditions (show steps please) sin(è/2); tan è = − 5 / 12 , è in Quadrant IV
*April 21, 2012*

**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?
*April 20, 2012*

**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
*April 20, 2012*

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

4.16%
*April 20, 2012*

**Physics**

Thanks Elena your a life saver :)
*April 20, 2012*

**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 ...
*April 20, 2012*

**math**

6/8
*April 19, 2012*

**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
*April 19, 2012*

**science**

Which of the following scales use the concept of absolute zero? I. C II. F III. K IV. R
*April 18, 2012*

**science**

Thermal energy is different from temperature because thermal energy depends on the _____.
*April 18, 2012*

**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?
*April 18, 2012*

**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?
*April 18, 2012*

**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?
*April 18, 2012*

**english**

thank you and for this one: Meredith is to be restored as captain.the infinitive is to be and is a noun?
*April 17, 2012*

**english**

so it is to use and it would be a adverb
*April 17, 2012*

**english**

okay and the second one is i have permission and its a adverb?
*April 17, 2012*

**english**

okay and the answer can only be a noun.adverb or adjective.
*April 17, 2012*

**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?
*April 17, 2012*

**english**

thank you ms.sue
*April 17, 2012*

**english**

what is the gerund phrase and the noun function of the gerund in the sentence 1.Her favorite pastime is entertaining friends.
*April 17, 2012*

**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.
*April 16, 2012*

**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 ...
*April 16, 2012*

**physics**

15.5
*April 15, 2012*

**Chemistry 1201**

Thanks so much!
*April 15, 2012*

**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...
*April 15, 2012*

**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...
*April 15, 2012*

**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?
*April 15, 2012*

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

can someone help me please????
*April 15, 2012*

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

tan(sin^-1(5/6)-cos^-1(1/5)
*April 15, 2012*

**Math**

Try 868
*April 15, 2012*

**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.
*April 15, 2012*

**psyc355**

30.9
*April 15, 2012*

**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?
*April 15, 2012*

**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.
*April 13, 2012*

**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?
*April 13, 2012*

**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. ...
*April 13, 2012*

**physics**

Calculate the internal energy of 25.0 g of low-density oxygen gas (O2) at a temperature of 255 K.
*April 13, 2012*

**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
*April 13, 2012*

**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.
*April 12, 2012*

**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.
*April 12, 2012*

**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.
*April 12, 2012*

**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.
*April 12, 2012*

**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...
*April 12, 2012*

**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
*April 12, 2012*

**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.
*April 12, 2012*

**Physics**

Three identical small Styrofoam balls of mass 1.53 g are suspended from a ﬁxed point by three nonconducting threads, each with a length of 56.4 cm and negligible mass. At equilibrium the three balls form an equilateral triangle with sides of 31 cm. What is the common ...
*April 12, 2012*

**algebra**

For the area of a circle is πr² as you stated so all you do is set 400 equal to πr² and solve for r. 400=πr²/π 127.32=r² √127.32)= r r=11.3 Same thing for this except you use 800 instead of 400 so. 800=πr² 254.64=r²...
*April 12, 2012*

**math**

You have 7 red marbles and 5 green marbles in a bag. You select one, do not replace it then select another. Find P(red,red) and P (green,green). Write probabilites as a percent and rounded to the nearest whole percent. Find P(red,green) and P (green,red). Compare.
*April 12, 2012*

**Physics**

Three identical small Styrofoam balls of mass 1.53 g are suspended from a ﬁxed point by three nonconducting threads, each with a length of 56.4 cm and negligible mass. At equilibrium the three balls form an equilateral triangle with sides of 31 cm. What is the common ...
*April 11, 2012*

**Chemistry**

What 3 compunds can be used to prepare oxygen in the laboratory? What are the reactions for each of the three compounds?
*April 10, 2012*

**College Algebra**

Annual profit in thousands of dollars is given by the function, P(x) = -.1x^2 + 50x - 300, where x is the number of items sold , x >= 0. 1.describe the meaning of the number -.1 in the formula. 2.describe the meaning of the number -300 in the formula. 3.find the profit for ...
*April 9, 2012*

**physics**

A down jacket has a surface area of 0.82 m2 and is filled with a 3.8 cm thick layer of down, which has a thermal conductivity of 6.0 10-6 kcal/(s · m · C°). The coat is worn by a person whose skin temperature is maintained at 27° C. The outer surface of ...
*April 9, 2012*

**physics**

The sun is 1.5 1011 m from the earth. (a) Over what surface area is solar radiation spread at this distance? (b) What is the total power radiated by the sun? (The sun delivers energy to the surface of the earth at a rate of approximately 1400 W/m2.) (c) Treating the sun as a ...
*April 9, 2012*

**physics**

A pot containing 1.09 liter of water, initially at 18°C, is placed on a 1101 W electric heating element. (a) How much heat must be supplied to the water to bring it to a boil? (b) How much heat is necessary to boil all the water away? What is the minimum time required to ...
*April 9, 2012*

**Financial Math**

Suppose that you decide to lease a car. At the end of the 48-month lease period, you need to make a lump-sum payment of $5000 if you want to keep the car. You decide to save up, just in case you decide to keep the car; if you don’t keep this car, you will still have saved...
*April 9, 2012*

**physics**

A 55.0 g ice cube, initially at 0°C, is dropped into a Styrofoam cup containing 318 g of water, initially at 18.2°C. What is the final temperature of the water, if no heat is transferred to the Styrofoam or the surroundings?
*April 9, 2012*

**physics**

How much energy expressed in units of food Calories (that is, kilocalories) is required to operate a 100 W light bulb for 14.70 hours?
*April 9, 2012*

**physics**

(a) How much heat is required to raise by 12.40°C the temperature of 1.4 kg of water. (b) How much heat is required to raise by 12.40°C the temperature of 1.4 kg of iron.
*April 9, 2012*

**math**

marcie, kim and yvonne are on the same softball team. (A). During the last season . Marcie hit 3 less than twice the number of home runs that kim hit let h represent the number of home runs that kim hit . write an expression that represents the number of home runs that Marcie ...
*April 8, 2012*

**english**

1. apa 2. mla 3. apa 4. mla 5. mla 6. apa 7. apa 8. mla 9. both 10. apa are these right answers
*April 8, 2012*

**english**

Choose and Place MLA, APA, or Both in the blank. _____1. In a work with a single author, the author’s last name and initials are listed in the works cited entries. _____2. In a work with a single author, the author’s full last name and first name are listed in the ...
*April 8, 2012*

**chemistry**

@Amanda, k
*April 7, 2012*

**Statistics**

Should companies use the same confidence interval each time a confidence interval is determined or should the level change based on situations? If it changes based on situations, what type of situations might call for higher confidence levels?
*April 6, 2012*

**Chemistry :((((**

Thank you so much!!! :)))))
*April 6, 2012*

**Chemistry :((((**

explain why the bond angles found for the molecules below is as given below. Methane 109.5 Ammonia 107.5 water 104.5
*April 6, 2012*

**english**

hello?
*April 5, 2012*

**english**

alright but what structure would it be?
*April 5, 2012*

**english**

i don't know
*April 5, 2012*

**english**

i just need help on it
*April 5, 2012*

**english**

well i know its not a infinitive phase
*April 5, 2012*

**english**

its asking what grammatical structure is italicized in the sentence
*April 5, 2012*

**english**

What grammatical structure is the italicized portion of the sentence? Although her personality had not changed at all, Megan looked quite different is it: adverb clause infinitive phrase past participial phrase elliptical clause adjective clause
*April 5, 2012*

**Chemistry**

During the synthesis of Ferrocene, deprotonation of cyclopentadiene is carried out using 1,2-dimethoxyethane (DME). If the deprotonation is carried out using MeOH, will the reaction be faster or slower? Why?
*April 5, 2012*

**Physics grade 12**

A horizontal beam of alpha particles are injected with a speed of 1.3x10^5 m/s into a region with a vertical magnetic field of magnitude 0.155T. A- How long does it take for an alpha particle to move half way through a complete circle? B- If the speed of the alpha particle is ...
*April 5, 2012*