Saturday

December 20, 2014

December 20, 2014

Total # Posts: 386

**Thermodynamic**

The equilibrium constant of a reaction is determined at 2 different temperatures: at -181°C, Keq = 2770 at -11°C, Keq = 640
*November 1, 2014*

**relativity**

A runs at speed 4c=5 toward B, who is at rest. C is between A and B. How fast should C run so that she sees both A and B approaching her at the same speed? i have tried this but not sure we have to use relativity i thing. else without that i solved and got 2c/5.
*October 23, 2014*

**Biology**

How do proteins leave the cell?
*October 15, 2014*

**Geometry**

The measure of an exterior angle of a regular polugon is given. Find the measure of an interior angle. Then find the number of sides. 1) The measure of the exterior angle is x.
*October 14, 2014*

**CHemistry**

Assuming the final concentration of chloride anion after the addition of HCl (precipitation step) was 0.1M, what is the remaining concentration of Ag+ in the solution? (pKsp for AgCl = 9.74)
*October 11, 2014*

**Physics**

a) An electron in an atom has a speed of 2.2 × 10^6 m/s and orbits the nucleus at a distance of 5 × 10^-11m. What is its centripetal acceleration? (already solved) 9.68x 10^22 m/s^2 b) A neutron star of radius 17 km is found to rotate at 5 revolutions per second. ...
*September 29, 2014*

**Physics HELP**

A ball is thrown horizontally at 15 m/s from a clifftop 60 m above the sea level. Find: a) the time to land; b) the angle at which it hits the water; ° below the horizontal c) the speed at which it hits the water.
*September 28, 2014*

**chemistry**

A sample of gas occupies 17mL at -112 degrees Celsius. Assuming the pressure is held constant, what volume does the sample occupy at 70 degrees Celsius?
*September 28, 2014*

**Physics**

A ball is thrown at 15.5 m/s at 42° above the horizontal. Someone located 30 m away along the line3 of the path starts to run just as the ball is thrown. How fast, and in which direction, must the catcher run to catch the ball at the level from which it was thrown?
*September 26, 2014*

**Math**

If 1/3 is equal to 2/6 how come my teacher says it is equal to 5/8?
*September 23, 2014*

**Physics**

I push a stack of six books (each weighting 4 kg) horizontally across a table to the right with a kinetic coefficient of friction uk = 0.5. I apply a force of 120 N. a) What is the acceleration of the books? b) what is the force of the rightmost book on its neighbor? Next, I ...
*July 11, 2014*

**PHYSICS**

So you know what the value for pi is, value for r is, and the value for V. So the only part is looking for h. You can achieve that by just manipulating the equation: V=pi(r^2)(h) into h=... V= pi*r^2*h V/ pi = r^2*h V/(pi*r^2) = h Then when you get the equation for h, you can ...
*July 11, 2014*

**Physics**

Do Newton's Law apply to motion inside your car? A.Yes, but only when at rest. B.Yes, but only when traveling at constant velocity or at rest. C.No, never. D.Yes, always. So I tried answering the question with D at first because I was thinking that it is a car in motion so...
*July 8, 2014*

**Chemistry**

Write the formula for a complex formed between Ni 2+ and NH3, with a coordination number of 5. Write the formula for a complex formed between Ni 2+ and CN–, with a coordination number of 4. I am having trouble with these problem because I don't really understand what ...
*June 1, 2014*

**Chemistry**

Consider a fuel cell that uses the reaction of ethanol with oxygen to produce electricity, CH3CH20H(l)+ 3O2(g)---> 2CO2(g)+3H2O Use thermodynamic data to determine the value of E°cell for this cell at 25 °C. I don't really know where to start. I got the standard...
*May 5, 2014*

**Chemistry**

Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Zn2 ] = 0.842 M and [Ni2 ] = 0.0100 M. Standard reduction potentials can be found here. reaction: Zn(s)+Ni^2+(aq)--->Zn^2+(aq)+Ni(s) standard reduction Zn: -.76 standard ...
*May 4, 2014*

**Chemistry**

separate this redox reaction into its component half-reactions. O2 + 4Cu-->2CuO Oxidation half-reaction: ? Reduction half-reaction: ? I believe that the Oxidation is copper and that reduction is oxygen. So I tried to write it as 4Cu^+ --> 4Cu + 4e^- O2^2- +4e^- ---> ...
*April 28, 2014*

**chemistry**

Where possible, classify these systems as reactant-favored or product-favored at 298 K. If the direction cannot be determined from the information given, classify the reaction as "Insufficient information". a)2A(g) + 3B(g) -->4C(g) delta H = -95kJ b)2A(g) + 2B(g...
*April 20, 2014*

**Maths **

write a directed number to show the size and direction of the number. Question john walked 10km east
*March 18, 2014*

**Physics GR12**

A bungee jumper of mass 75kg is stadnding on a platform 53m above a river. The length of the unstretched bungee cord is 11m. The spring costant is 65.6N/m. Calculate the jumper's speed at 19m below the platform on his first fall. [Also, please state which height you usd ...
*December 4, 2013*

**Please any math helper!!**

How do you do these questions, I have all my steps done until the last one: 2x(2x)^2: 2x(4x^2)? Now do I multiply or add the big numbers? also Im having trouble on these: 1. x^2(xy)^3: x2(x^3y^3) 2. 3x^2(2x)^3: 3x^2 (8x^3) 3. -2x^2y(3xy^2)^2 4. -(3x)^2: -(9x^2)? 5. 5x(2x^2)^2 ...
*September 11, 2013*

**Math Ms Sue check**

Do you know anyone else who can help?
*September 11, 2013*

**Math Ms Sue check**

Oh no, this is due tomorrow and I have a huge test on this concept tomorrow... But it's ok...
*September 11, 2013*

**Math Ms Sue check**

How do you do these questions, I have all my steps done until the last one: 2x(2x)^2: 2x(4x^2)? Now do I multiply or add the big numbers? also Im having trouble on these: 1. x^2(xy)^3: x2(x^3y^3) 2. 3x^2(2x)^3: 3x^2 (8x^3) 3. -2x^2y(3xy^2)^2 4. -(3x)^2: -(9x^2)? 5. 5x(2x^2)^2 ...
*September 11, 2013*

**Math **

How do you do these questions, I have all my steps done until the last one: 2x(2x)^2: 2x(4x^2)? Now do I multiply or add the big numbers? also Im having trouble on these: 1. x^2(xy)^3: x2(x^3y^3) 2. 3x^2(2x)^3: 3x^2 (8x^3) 3. -2x^2y(3xy^2)^2 4. -(3x)^2: -(9x^2)? 5. 5x(2x^2)^2 ...
*September 11, 2013*

**Math help**

How do you do these questions, I have all my steps done until the last one: 2x(2x)^2: 2x(4x^2)? Now do I multiply or add the big numbers? also Im having trouble on these: 1. x^2(xy)^3: x2(x^3y^3) 2. 3x^2(2x)^3: 3x^2 (8x^3) 3. -2x^2y(3xy^2)^2 4. -(3x)^2: -(9x^2)? 5. 5x(2x^2)^2 ...
*September 11, 2013*

**To: bobpursley or any math helper**

please help me on my questions, I have a big test tomorrow and I don't understand how to do some questions, please help me
*September 11, 2013*

**Math**

How do you do these questions, I have all my steps until the last one: 2x(2x)^2: 2x(4x^2)? Now do I multiply or add the big numbers? also Im having trouble on these: 1. x^2(xy)^3: x2(x^3y^3) 2. 3x^2(2x)^3: 3x^2 (8x^3) 3. -2x^2y(3xy^2)^2 4. -(3x)^2: -(9x^2)? 5. 5x(2x^2)^2 6. -...
*September 11, 2013*

**Physics II**

Two charges attract each other with a force of 3.0 N. What will be the force if the distance between them is reduced to one-ninth of its original value?
*September 10, 2013*

**to: bobpursley**

wait...so you were talking about this question: (c^2/3d^-1)^-2 I thought you were talking about this question: (2m^4n/3m^-1n^3)^-2 so is my answer to this question (2m^4n/3m^-1n^3)^-2 correct?
*September 8, 2013*

**to bobpursley**

is this the correct answer: 2m^-8n^-2/9m^2n^-6??
*September 8, 2013*

**to: bobpursley**

please help me with the last question, are the others all correct?
*September 8, 2013*

**To Ms.Sue or any Math helpers**

Can you please help me with my math law of exponent quesions, please check my answers, please its due very soon.
*September 8, 2013*

**Math: law of exponents check answers**

how would you turn this question:(2m^4n/3m^-1n^3)^-2 into a positive?
*September 8, 2013*

**Math: law of exponents check answers**

wait...so you were talking about this question: (c^2/3d^-1)^-2 I thought you were talking about this question: (2m^4n/3m^-1n^3)^-2 so is my answer to this question (2m^4n/3m^-1n^3)^-2 correct?
*September 8, 2013*

**Math: law of exponents check answers**

so the correct answer would be : 2m^-8n^-2/9m^2n^-6??
*September 8, 2013*

**Math: law of exponents check answers**

is the last one the only one that is wrong, please show me how to do the last one
*September 8, 2013*

**Math: law of exponents check answers**

how do you sqaure the last one?? please show me how
*September 8, 2013*

**Math: law of exponents check answers**

I know that anything to the power of 0 is 1 but I need help with these 2 questions and check my answers: (xy)^0 / (z^2a^1)= (-2mn^2)^1 / (pqm)^0= (xy^2z)^0= 1? Negative Exponents: it says to leave answers with positive exponents only, I did all these questions so please check ...
*September 8, 2013*

**algebra**

a store buys jeans for $24 each and marks them up 30%. what is the selling price of a pair of jeans?
*August 8, 2013*

**math please hurry**

A secret code must consist of three capital letters followed by a digit. Letters cannot be repeated. How many secret codes are possible? A. 140,400 B. 156,000 C. 175,760 D. 358,800
*May 19, 2013*

**ap calculus**

Solve the integral ∫csc(z+π/6)cot(z+π/6)dz
*May 18, 2013*

**Chemistry PLEASE HELP!**

Check all of the following statements which are TRUE for a titration. Select one or more: a. A suitable primary standard must be available. b. The concentration of the solution in the buret (the titrant) must be known before the titration is begun. c. Titrations can only be ...
*May 5, 2013*

**Chemistry 104 PLEASE HELP ME!!**

Determine the weight of Na2C2O4 which is required to react completely with 20.0ml of 0.02M KMnO4.
*May 5, 2013*

**Chemistry PLEASE HELP!**

For MnO2 it says the product is Mn2+ (manganese ions), so write For the second half-cell reaction, I got Br- + 3H2O ---> BrO3- + 6H+ 6e-. Now I believe that I have to multiply the manganese half-cell reaction by three to cancel out the number of electrons. Then, my answer ...
*May 3, 2013*

**Chemistry PLEASE HELP!**

Manganese dioxide reacts with bromide ions to form manganese ions and bromate ions in an acidic aqueous solution. Write the balanced equation for this reaction. Select one: a. Br- + MnO2 + 3H2O Mn2+ + BrO3- + 2H3O+ b. Br- + 3MnO2 + 6H3O+ 3Mn2+ + 9H2O + BrO3- c. 6Br- + MnO2 + ...
*May 3, 2013*

**Chemistry 104 PLEASE HELP ME!!**

Calculate Eo (reduction potential) for the following balanced reaction. NiO2 + 2H2O + 2Fe(OH)2 Ni(OH)2 + 2Fe(OH)3
*May 3, 2013*

**Chemistry 104**

Calculate Eo (reduction potential) for the following balanced reaction. NiO2 + 2H2O + 2Fe(OH)2 Ni(OH)2 + 2Fe(OH)3
*May 3, 2013*

**Chemistry 104**

Thank you for replying. Why do we add water to it?
*May 3, 2013*

**Chemistry 104**

The reaction of hydrogen peroxide, sulfuric acid and lead results in the production of lead sulfate in an acidic aqueous solution. Write the balanced equation for this reaction.
*May 3, 2013*

**math**

What is a unit price?
*April 22, 2013*

**Chemistry**

How many grams of magnesium nitride are formed from 45.1 moles of magnesium?
*April 16, 2013*

**heat energy**

help me convert 0.093cal/g¤c to j/kg/k
*March 20, 2013*

**Math**

18 play baseball, 17 play basketball, 30 play neither or both. I'm trying to make a Venn diagram but don't understand how. Please help!
*March 18, 2013*

**physics**

differences btw a window unit air-conditioner and split-unit air conditioner.(2)explain d working principle of a freeze dryer using a diagram
*March 14, 2013*

**physics**

what factors can affect a bodies temperature rise?
*March 14, 2013*

**Science**

how would tides be different if the moon revolves as fast as the earth rotate
*March 7, 2013*

**Chemistry**

The density of carbon in the form of diamonds is 3.51 g/cm^3. If you have a 40- carat spherical diamond, what is the diameter of the diamond in millimeters? (1 carat=0.200 g)
*March 7, 2013*

**chemistry**

which alkali metal form superoxidess?(2)explain why rubidium has a short life?
*March 7, 2013*

**chemistry**

explain why iron is paramagnetic?
*March 7, 2013*

**Chemistry**

Mercury dissolves in concentrated nitric acid, with the evolution of a reddish-brown gas, just as in the reaction shown in figure 5.4 on page 188 for copper. The oxidation state of the mercury after reaction is +2. Write a balanced net ionic equation for the reaction?
*March 7, 2013*

**Chemistry**

Mercury dissolves in concentrated nitric acid, with the evolution of a reddish-brown gas, just as in the reaction shown in figure 5.4 on page 188 for copper. The oxidation state of the mercury after reaction is +2. Write a balanced net ionic equation for the reaction?
*March 7, 2013*

**math**

y^2+4y-32=0 what is the greatest factor
*March 5, 2013*

**Social Studies**

"How was the free-trade trial of 1849 a victory for the Metis?" Was it because the 4 Metis offenders were given mercy and it also ended the HBC monopoly?
*January 13, 2013*

**algebra**

What is the solution of the system of equations? y = 3x + 7 y = x – 9
*December 21, 2012*

**algebra**

At the Wild Thing Zoo, you can rent a motorized cart to tour the grounds for a $4 initial charge and $4 per hour. An equation that represents the total cost y for x hours is y = 4 + 4x. At Safari Zoo, you can rent the same cart for a $3 initial charge and $5 per hour. An ...
*December 21, 2012*

**algebra**

In a basketball game, a regular basket was worth 2 points and a long-distance basket was worth 3 points. If there were 45 baskets in a game and 96 points total, how many regular baskets r and long-distance baskets l were made? Show the correct system of equations.
*December 21, 2012*

**algebra**

You decide to market your own custom computer software. You must invest $3,255 for computer hardware, and spend $2.90 to buy and package each disk. If each program sells for $13.75, how many copies must you sell to break even?
*December 21, 2012*

**geometery**

1.given the function y=x^2-4x+5,find the following: a.vertex b.maximum or minimum c.axis of symmetry d.y-intercept e.x-intercept(zeros) f.graph
*October 25, 2012*

**perimeter and area**

what is 800cm times 15cm help me find the area cm2
*October 19, 2012*

**Physics **

A bullet is fired straight up from a gun with a muzzle velocity of 148 m/s. Neglecting air resistance, what will be its displacement after 6.3 s? The acceleration of gravity is 9.8 m/s2 .
*October 7, 2012*

**Mathematics**

A jar has eight red, nine blue, and ten green marbles. What is the least number of marbles that you can remove from the jar and be certain that you have three of the same color?
*September 30, 2012*

**chem**

How much heat is necessary to change 5 grams of water at 10 degrees celcius to water at 70 degrees celcius?
*September 23, 2012*

**physics**

A small mass m hangs at rest from a vertical rope of length l that is fixed to the ceiling. A force F then pushes on the mass, perpendicular to the taut rope at all times, until the rope is oriented at an angle (theta)=(theta)0 and the mass has been raised by a vertical ...
*May 22, 2012*

**physics **

small mass hangs at rest from a vertical rope of length that is fixed to the ceiling. A force then pushes on the mass, perpendicular to the taut rope at all times, until the rope is oriented at an angle and the mass has been raised by a vertical distance . Assume the force&#...
*May 22, 2012*

**physics**

A large 63.0kg board is propped at a 44 degree angle against the edge of a barn door that is 2.5 m wide. How great a horizontal force must a person behind the door exert (at the edge) in order to open it? Assume that the coefficient of friction between the board and the door ...
*May 16, 2012*

**R.H dana**

i forgot my spelling words how do i prent my homework out miss.pitkin
*January 31, 2012*

**Spanish-I'm sorry SraJMcGin**

Hi SraJMcGin, I'm realy sorry I asked this question again-I never saw your post from a few days ago-I only saw what was posted by a Lore-that's why I asked what I did because the post by Lore changed some things around that I didn't understand-I never saw your post...
*January 5, 2012*

**Spanish-Thank you Ms. Sue**

Thank you. I appreciate it
*January 5, 2012*

**Spanish-Please check SraJMcGin**

Hi, I redid some of the answers as suggested yesterday from someone who responded to my post. Could you please see if I did them correctly-Thank you- I made the corrections-someone yesterday redid a question but the questions shouldn't be redone-that's my homework-the ...
*January 5, 2012*

**Spanish-8th grade-Please check**

I apologize. I posted once early yesterday and then late. The person who answered caught a few mistakes which I now corrected.However, the person who responded changed the questions which I had to answer.The questions can't be changed-all I had to do was answer them. All I...
*January 5, 2012*

**Spanish-8th grade**

I made the corrections-someone yesterday redid a question but the questions shouldn't be redone-that's my homeowrk-the answers isare mine and I'm not sure if they're correct. 1. ¿Dónde estuvo tu mama ayer? Mi mamá estuvo en la tienda. 2. &...
*January 5, 2012*

**Spanish-8th grade**

Thank you for helping- I see what is wrong in mamá-except number 3 was asking "adonde" not Dónde-would it still be same answer? Also, number 5, I'm not sure I understand-shouldn't la escuela be separate from "yo empecé" ??
*January 4, 2012*

**Spanish-8th grade**

Please check 1. ¿Dónde estuvo tu mama ayer? Mi Mama estuvo en la tienda. 2. ¿Tocaste un instrumento la semana pasada? Sí, yo toqué un instrumento la semana pasada. 3. ¿Adonde fuiste el lunes pasado? Yo fui a la escuela el lunes pasado...
*January 4, 2012*

**Spanish 8th grade**

I had to answer the above questions-I'm not sure if I answered them correctly-expecially number 3 Thank you for helping
*January 4, 2012*

**Spanish 8th grade**

1. ¿Dónde estuvo tu mama ayer? Mi Mama estuvo en la tienda. 2. ¿Tocaste un instrumento la semana pasada? Sí, yo toqué un instrumento la semana pasada. 3. ¿Adonde fuiste el lunes pasado? Yo fui a la escuela el lunes pasado? 4. ¿C...
*January 4, 2012*

**Spanish-Please check also**

Thank you for checking these-it was a typo in son conjugated as fueron Thank you again Happy New Year!!
*December 30, 2011*

**Spanish-Please check also**

I couldn't number these because it kept saying I wanted to post a website URL I had to conjugate each vwerb in the past tense for above assignment-thank you
*December 30, 2011*

**Spanish-Please check also**

hago-hice tiene-tuvo corremos-corrimos juego-jugué son-fueron juegan-jugaron piensa-pensó pienso-pensé entienden-entendieron tienen-tuvieron andan-anduvieron patinan-patinaron corren-corrieron pescan-pescaron hacen-hicieron pregunta-preguntó doy-di ...
*December 30, 2011*

**Spanish**

Thank you for answering and catching that one
*December 30, 2011*

**Spanish-Please another to check**

Please also check these-I had to post twice to get them listed-had a problem numbering the answers
*December 30, 2011*

**Spanish**

Did I conjugate these correctly? 1.tomo-tome 2.tengo-tuve 3.es-fue 4.quiero-quise 5.deseo-deseé 6.dicen-dijeron
*December 30, 2011*

**Spanish-8th grade**

I was told to conjugate poder in the past tense for 1-4-so I knew what I wa suppose to conjugate Thanks for helping me-I really appreciate it
*December 30, 2011*

**Spanish-8th grade-Please recheck**

Please recheck number eight
*December 30, 2011*

**Spanish-8th grade**

Number eight got cut off-it should read supieron I think??? I have Windows XP
*December 30, 2011*

**Spanish-8th gradePlease check**

After someone please checks this, could you also explain how to do accents on the keyboard-I always use Spanishtypeit which is a pain at times to go back and forth with- I have Windows PC
*December 30, 2011*

**Math**

An engineer is desingning a parabloic arch, the arch must be 15 m high , and 6 m wide, at a height of 8 m a) determine a quadratic fundtion that satisfies these conditions b) what is the width of the arch at its base
*October 25, 2011*

**Math**

The height , in metres, of the trajectory of a football is given by h(t)=2=28t-4.9t^2, where t is the time in height of the football and the time when the height is reached
*October 25, 2011*

**writing**

can someone proofread?
*October 10, 2011*

**writing**

Freedom Doesn’t Come Free What is something you can never show much gratitude for? Well, veterans have done many wonderful things for our country, especially freedom. Freedom is a debt that can we can never repay veterans for. One reason I said they fought for freedom was...
*October 10, 2011*