Friday

October 9, 2015
Total # Posts: 1,154

**Physics**

Two railroad cars, each of mass 7350 kg and traveling 80 km/h in opposite directions, collide head-on and come to rest. 1. How much thermal energy is produced in this collision?
*November 1, 2010*

**Physics**

A spring has a spring stiffness constant, k, of 420 N/m . 1. How much must this spring be stretched to store 30 J of potential energy?
*November 1, 2010*

**Physics**

A 66 kg bungee jumper jumps from a bridge. She is tied to a bungee cord whose unstretched length is 14 m, and falls a total of 34m. 1. Calculate the spring stiffness constant of the bungee cord, assuming Hooke's law applies. 2. Calculate the maximum acceleration she ...
*November 1, 2010*

**calculus**

find the inverse of q(x)=(x-5)^2
*October 31, 2010*

**calculus**

find the inverse of q(x)=(x-5)^2
*October 31, 2010*

**algebra**

For 1983 through 1995, the amount of private donations D (in millions) allocated to education can be modeled by D= 1.78t^3-6.02t^2+ 752t+ 6701 where t is the number of years since 1983. In what year was 14.3 billion of private donations allocated to education? (My main ...
*October 30, 2010*

**chemistry**

Thank you. I had quite a bit a trouble with this and appreciate the quick response.
*October 30, 2010*

**chemistry**

I'm kind of having difficulty with a question involving dimensional analysis. I'm confused how I would convert some units into others and what to divide. Here's the question. One 5lb Hershey's kiss is equivalent to how many little Hershey's Kisses? (1 ...
*October 30, 2010*

**MATHEMATICS**

HOW TO SOLVE THIS EQUATION: 0.2*Z + LOG(10.2*Z)= 3.512 THANKS IN ADVANCE
*October 29, 2010*

**Chemistry**

Cu (I): CN- Pb2+: CN-, SO3^2-, PO3^3-,MnO4- Ca2+: CN- Al3+: CN-, SO3^2-, PO3^3-,MnO4- Cr5+: CN-, SO3^2-, PO3^3-,MnO4- Pb4+: CN- Sn2+: CN- Mn2+:MnO4- Ag+:CN-, SO3^2-, PO3^3- H+: CN-, SO3^2-, PO3^3-,MnO4-
*October 27, 2010*

**Math PIZZAZZ**

Yeah it's halo
*October 25, 2010*

**pre-algebra**

what is 6 divided by 1 5/16?
*October 24, 2010*

**pre-algebra**

it takes 1 cup of liqiud fertilizer to make 7 1/2 gallons of spray. How much liquid is needed to make 80 gallons of spray?
*October 24, 2010*

**chemistry**

Which of the following would have a positive change in standard entropy at constant temperature? Choose all that apply. A) Burning octane to form carbon dioxide gas and water vapor B) Freezing titanium C) The endothermic dissolving of ammonium nitrate solid in water D) ...
*October 20, 2010*

**algebra**

10 2/3
*October 19, 2010*

**Organic Chemistry I**

You have isolated one of the isomeric dimethylcyclopentanes. on reaction it gives you 3 monochloroisomers, which of the possible pentanes is it? How do i do this? they dont give any choices, so how do i figure it out?
*October 18, 2010*

**Maths Calculus Derivative Integral - Urgent Please**

Use 2nd Fundamental Theorem of Calculus to find derivative of f(x) = integral of 2x^2 (at the top) to x-5 (at the bottom) of square root of Sin(x)dx
*October 18, 2010*

**physics**

sin of angle = opp/hyp (SOH) cos of angle = adj/hyp (CAH) tan of angle = opp/adj (TOA)
*October 18, 2010*

**math**

7n^2+9n+2 (7n + 2)(n + 1)
*October 17, 2010*

**Math**

Ok, so if I change it to 2x^2 to x-5 of square root of Sin(x)dx, does it make sense? We haven't done any examples with an x in both the top and bottom of the integral sign. Thanks
*October 17, 2010*

**Math**

Use 2nd Fundamental Theorem of Calculus to find derivative of f(x) = integral of 2x^2 to x-5 of square root of Sin(t)dt. Please help.
*October 17, 2010*

**math**

cosA = adj/hyp tanA = opp/adj sinA = opp/hyp
*October 17, 2010*

**Physics**

idk help
*October 15, 2010*

**college organic chemistry**

I mean, it's due in like 6 hours. And I still have no idea. !@#$%^& it.
*October 13, 2010*

**chemistry**

In which solution (acidic, basic, neutral water, or doesn't matter) is potassium bromide most soluble? a. acidic b. basic c. neutral d. doesn't matter
*October 10, 2010*

**chemistry**

A buffer solution is 1.00 M in NH3 and 1.10 M in NH4Cl. If 0.230 moles of NaOH are added to 1.00 L of the buffer, what is its pH? Assume the volume remains constant. Kb of NH3 = 1.8 multiplied by 10-5.
*October 8, 2010*

**chemistry**

How many grams of HCOOH are needed to make 3.7 liters of aqueous solution of pH=3.5? I have followed the steps for a similar problem posted;I found x to 3.16e-4 mol/L but I'm having trouble converting it to grams.
*October 6, 2010*

**chemistry**

x=3.6e-4 mol/L x 3.7L x 43.06g HCOOH/mol = 0.050g HCOOH. my online homework counted this as incorrect. am I not going about it the right way?
*October 6, 2010*

**chemistry**

I found that problem, however I'm having trouble finding the amount of gram. I found x to 3.16e-4 mol/L
*October 6, 2010*

**chemistry**

How many grams of HCOOH are needed to make 3.7 liters of aqueous solution of pH=3.5?
*October 6, 2010*

**Thermochemistry**

Path A A sample of gas in a cylinder of volume 3.96 L at 327 K and 3.28 atm expands to 7.34 L by two different pathways. Path A is an isothermal, reversible expansion. Calculate the work for Path A. Answer in units of J. Path B Path B has two steps. In the first step, the gas ...
*October 5, 2010*

**AP Chemistry !**

Can you help me with this? If you can, do it as detail as you can. If not, you can just give me the answer, i'll try to figure how you did it :| A sample of gas in a cylinder of volume 3.96 L at 327 K and 3.28 atm expands to 7.34 L by two different pathways. Path A is an ...
*October 5, 2010*

**AP Chemistry**

What is the value of w (work) when 2.6 moles of H2 expands from 25 liters to 50 liters against a constant external pressure of 1 atm, then expands further from 50 to 100 liters against a constant external pressure of 0.1 atm? Answer in calories. Answer in units of cal.
*October 5, 2010*

**geometry**

what is the area of a hexagon with a 48 inch perimeter? i know its 166.277 but i need that in square root form?
*October 3, 2010*

**AMERICAN HISTORY**

After the Emancipation Proclamation, many African Americans A)boarded trains for the West. B)opened weapons factories. C)rushed to join the Union army. D)started getting paid by planters.
*October 1, 2010*

**HISTORY**

During the early part of the war, Lincoln's main goal was to.. A.)reduce the power of the states. B.)preserve the Union. C.)stop the spread of slavery. D.)free the slaves.
*October 1, 2010*

**history**

so they bring out their own opinion? yes I think politics would be more influential then. is there anything else that would back that up?
*September 27, 2010*

**history**

law because you cant change it so you have it follow it?
*September 27, 2010*

**history**

-Law: Original intent: Literalism Meaning of the words Logical reasoning Stare decisis Balancing approaches -Politics: Preference-based approaches Strategic approaches External factors Public opinion Political partisans Interest groups
*September 27, 2010*

**history**

Discuss the role of law and politics in Supreme Court decision making. Which is more influential? Why?
*September 27, 2010*

**MATH**

A triangle with vertices A(–3, 4), B(3, 1),and C(–1, –5) is translated 5 units left and 3 units up. Find the coordinates of A', B', and C'.
*September 27, 2010*

**MATH**

28. Chase Quinn wants to expand his cut-flower business. He has 12 additional acres on which he intends to plant lilies and gladioli. He can plant at most 7 acres of gladiolus bulbs and no more than 11 acres of lilies. In addition, the number of acres planted to gladioli G can...
*September 27, 2010*

**MATH**

A triangle with the vertices A(–3, 4), B(3, 1), and C(–1, –5) is dilated by a scale factor of 2. Find the coordinates of A', B', and C'.
*September 27, 2010*

**MATH**

Which term(s) describe(s) the system? 3x – 2y = 7 –9x + 6y = –10 dependent consistent and dependent consistent and independent inconsistent
*September 27, 2010*

**MATH**

Which term(s) describe(s) this system? 4x + y = 8 3x – 2y = –5 dependent consistent and dependent consistent and independent inconsistent
*September 26, 2010*

**preschool**

Reading,Math,Social Studies,Science,Gym,Music,Writing,and Health
*September 23, 2010*

**physics**

total normal stresses of 110 and 40 kpa are applied to two planes at right angles in an element of soil. the shear stress acting on those palnes is 20 kpa. what must be the value of the pore pressure in the element if the minor principle stress in the elemnt is to be zero?
*September 19, 2010*

**10th grade**

see out of 500 if 6 people leave then how many will leave out of 600,000. so it will be (600,000 * 6) / 500.
*September 19, 2010*

**soil mechanics**

total normal stresses of 110 and 40 kpa are applied to two planes at right angles in an element of soil. the shear stress acting on those palnes is 20 kpa. what must be the value of the pore pressure in the element if the minor principle stress in the elemnt is to be zero?
*September 19, 2010*

**math(please help)**

take 2 on left hand side which would be in denominator anr square both the sides so it will be (x/2)^2 = 6x-36 now solve the equation and thr u go with the ans.
*September 19, 2010*

**maths**

for tan2x=3 i get should get two values 71.56 and 251.56 but i dnt knw how to solve to get this two values. pls help me with this. thanx in advance.
*September 19, 2010*

**AP Chemistry**

HBr is mixed with water. Which is the best description of what you would expect to find in the solution? 1. H3O+, Br1−, and water molecules 2. HBr molecules, H3O+, Br1−, and water molecules 3. Br+, OH1−, and water molecules 4. HBr molecules and water ...
*September 17, 2010*

**AP Chemistry**

so what would be the answer?
*September 17, 2010*

**AP Chemistry**

Although soluble barium compounds are toxic, suspensions of insoluble barium sul- fate are routinely swallowed for upper gas- trointestinal X-ray studies. Why is barium carbonate not used? 1. Barium carbonate is too expensive. 2. Barium carbonate is soluble in plain wa- ter. 3...
*September 17, 2010*

**math**

m of angle 7=2x + 10 m of angle 3=3x - 15
*September 16, 2010*

**calculus**

thanks
*September 14, 2010*

**calculus**

Assume a substance has a half-life of 11 years and the initial amount is 144 grams. How much remains at the end of 5 years? How long will it be until only 30 % remains?
*September 14, 2010*

**language**

I am trying to do a report on the following and can't find any sites that contain info to make report. Looking for various types of humans that have lived on earth since time began. thanks for any help
*August 26, 2010*

**college- strength of material**

Thnx drwl but i knw the fomulas but i dnt knw hw to plot a graph wen juz max load is given.
*August 19, 2010*

**college- strength of material**

i have initial and final gauge length and diameter and also have max load. Now i have to draw stress strain diagram. I know how to draw tht graph but i a not provided with failure load or yield load so i am not sure how to graph. We had performed experiment and data was given ...
*August 19, 2010*

**college**

hey we performed experiment and lecturer mailed the results which doesnt have any series of results just one result. And gauge length is length of the specimen used.
*August 18, 2010*

**college**

I have initial and final gauge length and diameter and also have max load. Now i have to draw stress strain diagram. I know how to draw tht graph but i a not provided with failure load or yield load so i am not sure how to graph. Appreciate any help. Thanx in advance
*August 18, 2010*

**Chemistry**

(50g)(0.107 cal/g degreesC)(tfinal-15C) +(25g)(1.000 cal/g degreesC)(tfinal-45C) is this correct
*August 7, 2010*

**Chemistry**

what is the final temp of the combination when 50 grams of chromium at 15 degrees celcius is added to 25 milliliters of water at 45 degrees celcius?
*August 7, 2010*

**trigo**

sin 47 degree 29 minutes = x/4728 x=4728(sin 47 degrees 29 minutes) x=3484.92m cos 47 degree 29 minutes= y / 4728 y= 4728(cos 47 degrees 29 minutes) y= 3195.20 m Am i correct?
*August 3, 2010*

**business communication**

Your boss wants to send a brief email message welcoming employees recently transferred to your department from your Hong Kong branch. They all speak English, but your boss asks you to review his message for clarity. What would you suggest your boss change in the following ...
*July 28, 2010*

**Physics**

Agree with Charlie, but try finding the net force and use Newton's 2nd law maybe.
*July 6, 2010*

**English**

So you go to Keystone Online Highschool? 9th grade? Me too. These answers were very helpful in me constructing my own answers. And you made many spelling errors, you also only had 1 space instead of 2 spaces after a period in many places. You should try putting your papers ...
*June 24, 2010*

**PARTICLE PHYSICS**

particle A has a mass of 2 and a charge of -1. particle B has a mass of 2 and a charge of +1. are particle A and particle B necessarily antiparticles? explain your answer
*June 9, 2010*

**physics**

19.6
*June 7, 2010*

**Chemistry**

15. What volume of NH3 at STP is produced if 25.0g of N2 is reacted with an excess of hydrogen gas? N2 + 3H2 →2NH3
*June 3, 2010*

**fluid mechanics**

I have got differential pressure from an inclined manometer to be 2.8kPa and density of the fluid is 784kg/m^3. I need to calculate the manometer datum height. how do i do tht?? i already did it using formula pressure=density*g*h but i want ans to be 0.165 meters which i dnt ...
*May 30, 2010*

**fluid mechanics**

yes i used the ame formula but didnt get the correct ans. cn u help me solve it. i want ans to be 6.5 inch (0.165 meters).
*May 29, 2010*

**fluid mechanics**

I have got differential pressure from an inclined manometer to be 2.8kPa and density of the fluid is 784kg/m^3. I need to calculate the manometer datum height. how do i do tht?? thnx for the help in advance.
*May 29, 2010*

**Math Algebra 1a **

Soybean meal is 18% protein, cornmeal is 9% protein. How many pounds of each should be mixed together in order to get a 360-lb mixture that is 10% protein? Cornmeal-how many pounds:__________ Soybean meal-how many pounds:______
*May 27, 2010*

**m/c**

sample statistic
*May 20, 2010*

**Geometery**

How would I calculate the perimeter of a hexagon (which can be divided into 6 congruent equilateral triangles) which is inside a circle with an area of 314^2 cm? Many thanks
*May 13, 2010*

**Math**

How would I calculate the perimeter of a hexagon (which can be divided into 6 congruent equilateral triangles) which is inside a circle with an area of 314^2 cm? Many thanks
*May 11, 2010*

**Algebra**

Hi, how would I factorise x^2-100?
*May 7, 2010*

**College Chemistry**

A spherical rubber balloon has an initial thickness of 0.45mm, and diameter 250mm. Final diameter of 1000mm. Find final thickness, true stress in the plane of the balloon wall, Air pressure required. (Assume rubber is idea and obeys Guassian statistics, and take the shear ...
*May 6, 2010*

**Chemistry**

A spherical rubber balloon has an initial thickness of 0.45mm, and diameter 250mm. Final diameter of 1000mm. Find final thickness, true stress in the plane of the balloon wall, Air pressure required. (Assume rubber is idea and obeys Guassian statistics, and take the shear ...
*May 6, 2010*

**polymer chemistry**

A spherical rubber balloon has an initial thickness of 0.45mm, and diameter 250mm. Final diameter of 1000mm. Find final thickness, true stress in the plane of the balloon wall, Air pressure required. (Assume rubber is idea and obeys Guassian statistics, and take the shear ...
*May 5, 2010*

**chemistry**

A spherical rubber balloon has an initial thickness of 0.45mm, and diameter 250mm. Final diameter of 1000mm. Find final thickness, true stress in the plane of the balloon wall, Air pressure required. (Assume rubber is idea and obeys Guassian statistics, and take the shear ...
*May 5, 2010*

**math**

A sheet of plywood measures 4 feet by 8 feet. Armand wants to build a dog house using one whole sheet of plywood for the floor. a. Armand needs to put a "2 by 4" under the outer edges all the way around the floor, and another "2 by 4" that runs down the ...
*May 4, 2010*

**Chemistry 102**

For a question like “calculate the pH of an aq.solution that is 1.0 M CH3COOH and 1.0 M CH3COONa, how do you know to write the equation like this: CH3COOH + H2O => H3O+ + CH3COO- and not like H3O+ + CH3COO- => CH3COOH + H2O for the ICE chart. This would switch the ...
*May 3, 2010*

**chemistry**

SO2 (5.00 g) and CO2 (5.00 g) were placed in a 750.0 mL container at 50.0 °C. The partial pressure of CO2 in the container was __________ atm.
*May 2, 2010*

**Physics**

given; r2 = 0.05 m r1 = 0.01 m Q = 10 liters/min = 10 E-3/60 = 1.67 E-4 m³/s P2 = 10^5 Pa ρ = 1000 kg/m³ no. # (a) Q = (A2)(v2) Q = π(r2)²)(v2) 1.67 E-4 = π(0.05)²)(v2) V2 = 0.0212 m/s no. # (b) V1 = (r2/r1)² (V2) = (5/1)² (0.0212) ...
*April 27, 2010*

**Physics**

A) V1= 10L/((pie)(.05^2)(1000)(60))=.0212m/s B) V2= 10L/((pie)(.01^2)(1000)(60)=.5307m/s C)P=P1 - P2 = 1000*[(.0212)²/2 - (.5307)²/2] P1 - P2 = 140.5 Pa P2 = 10^5 - 140.5 = 99859.5 Pa.
*April 27, 2010*

**Math 102**

if you have a pizza with a diameter of 20 that is cut equally into 4 pieces, one way horizontal and one way vertical. how do i figure out where to place 2 non-center vertical cuts so that the pizza has 8 equal parts? i found the area for the circle to be 314.159 (divided by 8...
*April 27, 2010*

**5th grade**

Find the numbers that each letter stands for in the problem below. EFGH X 4 = HGFE E= F= G= H=
*April 22, 2010*

**Science**

That depends on the density of the object along with bouyancy. A 2g rock will sink in water whereas a 2000 kg boat will not (if made right). It doesnt matter what something weighs. An object floats because it displaces an amount of water equal to or more than its own weight. A...
*April 22, 2010*

**math**

Essentially you look for key words. "At most", "no more than", "does not exceed", etc. would mean less than or equal too. Taking your example, if the cost is at most $4857.95, then it could be less, but it cannot be more. When x is less than or ...
*April 21, 2010*

**chemistry**

I did the moles of Cl found/1 L = .00863. 1.8e-10 / .00863 = 2.1e-8 * 1 L = 2.1e-8 moles .0010 / 2.1e-8 = 47619 L*1000 mL / .5 but the answer comes out wrong=/
*April 21, 2010*

**chemistry**

ag2so4 ksp = 1.5 e10-5
*April 21, 2010*

**chemistry**

A certain municipal water sample contains 46.1 mg SO42-/L and 30.6 mg Cl -/L. How many drops (1 drop = 0.05 mL) of 0.0010 M AgNO3 must be added to 1.00 L of this water to just produce a precipitate? What will this precipitate be? how do i do this problem? agcl ksp = 1.8 e-10
*April 21, 2010*

**Chemistry 102**

A certain municipal water sample contains 46.1 mg SO42-/L and 30.6 mg Cl -/L. How many drops (1 drop = 0.05 mL) of 0.0010 M AgNO3 must be added to 1.00 L of this water to just produce a precipitate? What will this precipitate be? How do i start this question? please help
*April 21, 2010*

**Chemistry 102**

The Ksp for cerium iodate, Ce(IO3)3 is 3.2 e-10. What is the molar solubility of Ce ion in pure water? = .0019 M B) A 0.031 M sodium iodate is added as a common ion. What is the concentration of Ce ion with the common ion present? C) What is the ratio of the Ce ion with the ...
*April 21, 2010*

**math**

mix and match the shake sizes to equal using 3 cups
*April 14, 2010*

**math**

Liann works in the old time soda shoppe the shop sells shakes. a single shake uses 1/8 cup syrup, a double shake uses 1/4 cup syrup, a tripple milk shake uses 3/8 cup syrup. How many shakes can she make of each with 3 cups of syrup?
*April 14, 2010*

**science**

Given the following reaction, with Kp=1.05 at 250 degrees C what is Kc? The reaction is PCl5 to PCl3+Cl2
*April 13, 2010*