Friday

May 22, 2015

May 22, 2015

Total # Posts: 313

**Chemistry**

At what temperature would 1.3 m NaCl freeze, given that the van't Hoff factor for NaCl is 1.9? Kf for water is 1.86 deg C/m.
*February 5, 2012*

**Chemistry**

At a certain temperature, the solubility of N_2 gas in water at 2.38 atm is 56.0 mg of N_2 gas/100 g of water. Calculate the solubility of N_2 gas in water, at the same temperature, if the partial pressure of N_2 gas over the solution is increased from 2.38 atm to 5.00 atm.
*February 4, 2012*

**Calculus**

Find the volume of the solid whose base is the region bounded by y=x^2 and the line y=0 and whose cross sections perpendicular to the base and parallel to the x-axis are semicircles.
*January 29, 2012*

**Calculus**

I use this to check my answers. I apologize for not realizing that I should have proven to you that I was doing them by myself at first.
*January 29, 2012*

**Calculus**

Find the volume of the solid formed when the region bounded by y=3x^2 and y=36-x^2 is revolved about the x-axis.
*January 29, 2012*

**Calculus**

Let R be the region bounded by y=x^2, x=1, and y=0. Use the shell method to find the volume of the solid generated when R is revolved about the line x=-11.
*January 29, 2012*

**Calculus**

Let R be the region bounded by y=x^2, x=1, and y=0. Use the shell method to find the volume of the solid generated when R is revolved about the line y=-2.
*January 29, 2012*

**Biology/Chemistry**

Consider that the human brain weighs about 1 kg and contains 10^11 cells. Assuming that each cell is entirely filled with water, and knowing that 1 cm^3 of water weighs 1 g, calculate the volume of a brain cell (in picoliters).
*January 26, 2012*

**Chemistry**

A sample of steam with a mass of 0.550 g and at a temperature of 100 degrees C condenses into an insulated container holding 4.40 g of water at 5.0 degrees C. Assuming that no heat is lost to the surroundings, what will be the final temperature of the mixture?
*January 25, 2012*

**quadratic equations**

Thank you Steve, your a life saver,and I appreciate your help!!!
*January 24, 2012*

**quadratic equations**

Suppose you are an event coordinator for a large performance theater. One of the hottest new Broadway musicals has started to tour and your city is the first stop on the tour. You need to supply information about projected ticket sales to the box office manager. The box office...
*January 24, 2012*

**Calculus**

Find the volume of the solid generated by revolving the following region about the given axis. The region in the first quadrant bounded by the curve y=x^2, below by the x-axis, and on the right by the line x=1, about the line x=-2
*January 24, 2012*

**Calculus**

Use the disk method to find the volume of the solid generated when the region bounded by 4= 1/(fourth root of (1-11x)), y=0, x=0, and x=1/22.
*January 24, 2012*

**Calculus**

Use the disk method to find the volume of the solid generated when the region bounded by y=15sinx and y=0, for 0 </= x </= pi, is revolved about the x-axis.
*January 24, 2012*

**Chemistry**

Sorry, I never saw this response so I reposted it correctly! But I do have a question. I used 2257 kJ/kg for the heat vap. and 2.08 J/g*K for the specific heat of water. I'm still getting the problem wrong, am I plugging in the wrong numbers??
*January 24, 2012*

**Chemistry**

It is 100 degrees, I just mistyped!!
*January 24, 2012*

**Chemistry**

A sample of steam with a mass of .550 g and at a temperature of 1 degrees C condenses into an insulated container holding 4.40 g of water at 5.0 degrees C. Assuming that no heat is lost to the surroundings, what will be the final temperature of the mixture?
*January 24, 2012*

**chemistry**

How much energy (in kJ) is released when 16.4 g of steam at 121.5 degrees C is condensed to give liquid water at 60.5 degrees C? The heat of vaporization of liquid water is 40.67 kJ/mol and the molar heat capacity is 75.3 J/(K*mol) for the liquid and 33.6 J?(K*mol) for the vapor.
*January 24, 2012*

**algebra **

I need help breaking down the steps to solve HELP ME PLEASE solve with an exact answer. x^2 + 2x - 8
*January 17, 2012*

**Quadraitic equations**

Thank you so much and I definetly need to review how to factor equations<<<good night and sweet dreams>>>thank you for helping me
*January 17, 2012*

**Quadraitic equations**

Can you show me the steps please???? to solve this equation.
*January 17, 2012*

**Quadraitic equations**

solve with an exact answer. x^2 + 2x - 8
*January 17, 2012*

**quadratic equations**

can you solve the equation using the quadratic formula x2 + 3x = 7? Explain and provide an exact answer.
*January 17, 2012*

**algebra**

Thanks
*January 17, 2012*

**algebra **

a two part canoe trip,the first part of the trip the canoist traveled 58 miles.Second part of the trip he traveled 18 miles at 5mph slower.the total time for trip was 4 hours.What was the speed of both parts of the trip?
*January 17, 2012*

**algebra**

Thank you!
*January 17, 2012*

**algebra**

solve by completing the square x^2-10x=10
*January 17, 2012*

**calculus**

find the slope of the tangent line at the point P(1,1) on the graph of e^x-y=2x^2-y^2
*January 17, 2012*

**calculus**

An airplane flying west at 300 miles per hour goes over the control tower at noon, and a second airplane at the same altitude, flying north at 400 miles per hour, goes over the tower an hour later. How fast is the distance between the airplanes changing at 2:00 P.M.?
*January 17, 2012*

**Algebra **

REMOVING FACTOR OF 1: 4Z-24/6-Z
*December 17, 2011*

**Algebra**

The cost, in millions, to remove x% of pollution in a pond is modeled by the equation: C=6350/(425-3x) . What is the cost to remove 75% of the pollution? Hint: Plug in and calculate, do not convert to a decimal. Can someone tell me how figure this out step by step recheck my ...
*December 15, 2011*

**Algebra**

1.50 per animal. 2200.00 for set-up and 1,50 per animal ??? are you sure your right???
*December 14, 2011*

**Algebra**

Opps I think the other one was wrong so here's my new answer: (2200 + 1.5x)=1.5*25+$2,200 =$2,237.50
*December 14, 2011*

**Algebra**

Scientists want to set up and test animals in the area for West Nile. The costs to test are $2,200 for setup plus $1.50 to administer each test. (2200 + 1.5x)/x What is the average cost to test 25 animals?250 animals??1000 animals??? (2200 + 1.5x)=2201.50 *25 =2239.00 Is this ...
*December 14, 2011*

**Algebra**

, what value of x would make the equation undefined? Hint: Think about what makes an equation undefined. Then calculate what value would make this equation undefined. Any ideas????? help
*December 14, 2011*

**Algebra**

The cost, in millions, to remove x% of pollution in a pond is modeled by the equation: C=6350/(425-3x) What is the cost to remove 75% of the pollution? Plug in and calculate, do not convert to a decimal.
*December 14, 2011*

**Algebra **

HELP!!!!!!!If 59 people use 15,045 cans in 1 year. How maNY CANS are used in a city with a population of 1,562,000???
*December 13, 2011*

**chemistry**

2H2 (g) O2 (g) --> 2H2O (g) if 44 g of O2 are reacted , determine the amount if heat transferred in the reaction when the Heat = -483.6 kJ
*December 12, 2011*

**chemistry**

2H2 (g) O2 (g) --> 2H2O (g) if 44 g of O2 are reacted , determine the amount if heat transferred in the reaction when the Heat = -483.6 kJ
*December 12, 2011*

**physiology**

Pepsin would have the greatest activity... a.)when the pH of the chyme is greater than 3. b.)immediately upon entering the duodenum. c.)immediately upon secretion into the stomach. d.)when the pH of the chyme is less than 3.
*December 10, 2011*

**physiology**

True or False The secretion of GnRH, FSH, and LH are pulsatile instead of continuous?
*December 4, 2011*

**physics**

A propeller spins at 1850 rev/min. (a) What is the angular velocity in rad/s? (b) What is the angular displacement of the propeller in 4.10 s?
*November 28, 2011*

**chemistry**

i have this exact same problem and i cannot figure out the answer. can you please help?
*October 3, 2011*

**chemistry**

did u get the answer?
*October 3, 2011*

**math**

sig figs for.. 1.399 x by 10-3 0.0763 m2 212.080 g 673.133 K 6.69808e+06 cm
*October 2, 2011*

**Academic and Professional Success**

Email a teacher, or tell your partner how you feel. Kindly, just give them advice on what to improve on in their portion. If that doesn't work, talk to a teacher and tell them that you feel your partner's work is insufficient, and that you want and feel you deserve an...
*September 30, 2011*

**Physics**

At 1:00 p.m. a car, traveling at a constant velocity of 96 km/h toward the west, is 24 km to the west of our school. How far from the school will it be at 3:30 p.m.? Answer in units of km. I've been attempting this problem for at least 30 minutes and not getting the right ...
*September 30, 2011*

**Science**

The problem I'm trying to answer is: Ann is driving down a street at 59 km/h. Suddenly a child runs into the street. If it takes Ann 0.719 s to react and apply the brakes, how far will she have moved before she begins to slow down? Answer in units of m. I know the first ...
*September 30, 2011*

**calculus**

Find the volume of the solid obtained by rotating the region under the graph f(x) = x2 - 3x about the x-axis over the interval [0, 3].
*September 25, 2011*

**Art**

What elements of painting are important to Renaissance artists?
*September 17, 2011*

**Art History**

How does Perugino's work represent the ideas of Humanism and the Renaissance?
*September 17, 2011*

**chemistry**

If a swimmer has a lung volume of 6 at sea level, what would the volume of her lungs be when she is at the bottom of a pool that is 5 deep? Assume that the temperature and amount of the air in the lungs remain unchanged.
*September 2, 2011*

**math**

16 divided by 2[8-3(4-2)] +1
*June 27, 2011*

**Chemistry **

where in the atom would you put a region of fixed small volume if you wished to maximize the chance o finding the electron inside the volume?
*April 24, 2011*

**English**

It's all right, the way I changed the paragraph nullified the use of a semi-colon anyways :) Thanks!
*April 19, 2011*

**English**

Is this a correct use of a semi-colen?: "However Petra was taken over in 100 CE by the Romans, and was still occupied during the Byzantine period; but it soon became not as much of an importance after that, besides being used as a fort for the Crusaders in the 12th ...
*April 19, 2011*

**English**

Thanks!
*April 10, 2011*

**English**

What does the word "curfew" mean in this sentence: "A game well played, but curfew is past!"
*April 10, 2011*

**Physics rollerblading question**

1) Suzie (of mass 38 kg) is roller-blading down the sidewalk going 20 miles per hour. She notices a group of workers down the walkway who have unexpectedly blocked her path, and she makes a quick stop in 2 seconds. What is Suzie’s average acceleration? Answer in units of ...
*March 25, 2011*

**English **

What does it mean when your teacher asks you "identify" the climax of a novel?
*March 16, 2011*

**chemistry**

what mass of K2SO4 would you measure out to prepare 550 mL of a 0.76 M solution?
*February 7, 2011*

**science**

C2H508+x02_>2C02+3H2=X=23 DUMB***
*February 6, 2011*

**Chemistry**

5x8=40 4x10=40 5 bun packages 4 hotdog packages
*January 31, 2011*

**English**

Thank you! :)
*January 11, 2011*

**English**

Would this be an example of figurative language? Sorry, I am really terrible at this kind of thing, and knowing what is right and wrong really helps me. "O, gentlemen, see, see! dead Henry's wounds Open their congeal'd mouths and bleed afresh!"
*January 11, 2011*

**English**

Thank you so much!
*January 11, 2011*

**English**

Are the following sentences figurative language: "With lies well steel'd with weighty arguments."
*January 11, 2011*

**English **

Is this sentence a type of figurative language? "That laid their guilt upon my guiltless shoulders"
*January 11, 2011*

**chemistry**

Idk how to do
*January 6, 2011*

**Finance**

NPV= 13 IRR= 50
*January 2, 2011*

**General Chemistry**

C6HO2
*December 8, 2010*

**Chemistry**

What is the theoretical yield of PI3 from the reaction of 27.0 g of P and 68.0 g I2? 2P(s)+3I2(s) 2PI3(s)
*December 8, 2010*

**Chemistry**

I dont understand how to do any of this stuff. it just goes over my head.
*December 8, 2010*

**Chemistry**

A sample of unknown ore was analyzed and fgound to contain 12.7% Al, 19.7% N,and 67.6% O. What is the empirical formula of this ore?
*December 8, 2010*

**Chemistry**

Calculate the energy of a photon of light with a wavelength of 360 nm?
*December 8, 2010*

**Chemistry**

using the gas laws, What is V in the table below? initial: 1420 torr 75 mL 200 K Final: 760 torr V 360 K What is T using the gas laws? Initial: 91.8 mL 365 K Final: 45.8 mL T
*December 8, 2010*

**chemistry**

using the lewis dot structures, predict the formula for the compound formed between lithium and chlorine.
*December 5, 2010*

**science**

Baceria are placed into two different areas . these area are??
*December 4, 2010*

**physics **

A cannon fires a shell at an angle of 55.0° above the horizontal. The shell has a mass of 17.5 kg, and its initial speed as it leaves the cannon is 289 m/s. The cannon is not anchored to the ground. It is mounted on a base—a large block of wood—which is sitting ...
*November 1, 2010*

**physics **

A playground carousel (“merry-go-round”) is free to rotate frictionlessly in the horizontal plane (and air resistance is negligible). Without riders, the carousel has a moment of inertia of 152 kg·m2. But there is a single rider, initially standing 1.85 m from...
*November 1, 2010*

**Psychology ; the mind at work**

I got a 35 thanks to S. Almost none of your answers were correct.
*October 21, 2010*

**AP Chemistry Born-Haber Cycle?**

When using the Born-Haber Cycle for Na2S, do I double the ionization energy of Na since there are two Na ions for every S ion in Na2S? Also, the problem asked me to find the change in energy for S- (g) + e- => S2- (g). Assuming that you do double the ionization energy, I ...
*October 17, 2010*

**Math**

-4=x/7+3 i need to find the answer for "x"
*October 11, 2010*

**9th grade Science (Biology)**

i think its the volume
*August 1, 2010*

**ipc**

a box 5 m long 2m wide and 2m high applies 12 Pa of pressure to the table that it is resting on how much force does the box exert
*June 3, 2010*

**poetry**

i need help with 3 more lines: "two boys were playing bythe curb, a trail of ants close by did swerve, the blazing sun beat down from on high, ------------------------ ------------------------ ------------------------
*May 17, 2010*

**math**

i did 26 *26*9 because there are 26 letters in an alphabet, and just 1 letter can go into 26 (counting its self) and 9 because it has to be 1 number. so 26*26*9=6084
*May 17, 2010*

**math**

i have more than one question so if u no any of the answers please tell me 1.) write the point-slope form of the equation of the line with slope -2 passing through the point ( -5, -9). 2.) write the point-slope form of an equation of the line through the points at ( -9, -9) ...
*May 17, 2010*

**9th grade**

bryan berg built an 83-story house of cards in 1995. he used 27,000 playing cards to accomplish this feat. at this same rate, about how many cards would it take to build a 100-story house of cards?
*May 17, 2010*

**Chemistry**

i. calculate the pH of the .833 sodium acetate solution ii. Calculate the pH after adding .700 grams of NaOH to the 35 ml of .833 M sodium acetate solution iii. Calculate the pH after adding 1.5 mL of 12 M HCl to the original 35 mL of .833 M sodium acetate solution
*April 30, 2010*

**Geography**

Ms. Sue retire. It is a nation-state:a political entity (a state) associated with a particular cultural entity (a nation)
*April 21, 2010*

**music help PLZ**

any 1 plzz
*April 18, 2010*

**music help PLZ**

i am on windows media player tryin to make a mix cd. i made a playlist but i wanna cut some parts into smaller pieces like if i only want a certain part of the song then it will continue to the next song does any1 no how to do that ..Like how to cut the songs into 2 cetain ...
*April 18, 2010*

**drwis**

can some1 plz help me with this question i have 2 submit my exam
*April 17, 2010*

**drwis**

-Which greek base means narrow? 1. sten- 2. platy- 3. mer- 4. xanth
*April 17, 2010*

**plzzz help me with this questionnn**

omg Thank You so much ive been tryin 2 get this answer 4 ever lol
*April 17, 2010*

**plzzz help me with this questionnn**

which word is a synonym of the word evolve? a.recession b.decline c.progress d.retrogression plzzzz some1 give me the answer:((
*April 17, 2010*

**physics**

ok well off 2 bed adios...lol
*April 16, 2010*

**physics**

sorry samuel i dont no if u gonna get any help wit that now at this time ive been tryin to get respawns for the past 10 min post agian 2mmorow remember jiskha is the best:)
*April 16, 2010*

**math**

The vertex of a parabola is(-2,-4). One x-intercept is 7. What is the other x-intercept?
*March 22, 2010*