Thursday
March 30, 2017

Post a New Question

Posts by Anon

Total # Posts: 2,729

Math
A college football coach wants to know if there is a correlation between his players' leg strength and the speed at which they can sprint 40 yards. He sets up the following test and records the data: Every day for a week, he counts how many times each player can leg press ...
March 28, 2017

Social studies
What negative impact did gold and silver mining have in the West
March 27, 2017

Chemistry
I know, that is why I am confused choosing an answer.
March 26, 2017

Chemistry
The following ions contain three oxygen atoms: A) carbonate, sulfite, and nitrite B) sulfite, nitrate, and bromate C) sulfate, hypochlorite, and carbonate D) chlorate, iodate, and phosphite I know I can eliminate A and C.
March 26, 2017

Chem
Calculate the standard enthalpy change for the reaction: 2C8H18(l) + 17O2(g) --> 16CO(g) + 18H2O(l) Given: 2C8H18(l) + 25O2(g) --> 16CO2(g) + 18H2O(l): ?Hº = -11,020 kJ/mol 2CO(g) + O2(g) --> 2CO2(g): ?Hº = -566.0 kJ/mol
March 26, 2017

Chemistry
Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from 15.4ºC to 93ºC. The specific heat of water = 4.18 J/gºC. q = ms?T q = (12.0g) (4.18) (93.0 - 15.4) q = 3892.416 J ??
March 26, 2017

Chemistry
Potassium is a reactive element. Bromine is a reactive element. Write the complete balanced chemical equation using appropriate chemical symbols for the reaction when potassium reacts with bromine to make a solid product showing correct symbols and states of reactants and ...
March 26, 2017

Chemistry
The enthalpy of combustion of benzoic acid (C6H5CO2H) is –3228 kJ/mol. The burning of 1.698 g of benzoic acid in a calorimeter causes the temperature to increase by 2.865 ºC. What is the heat capacity (in kJ/ºC) of the calorimeter?
March 25, 2017

Chemistry
Given H2(g) + (1/2)O2(g) --> H2O, ?Hº = -286 kJ/mol, determine the standard enthalpy change for the reaction 2H2O(l) --> 2H2(g) + O2(g). Just checking... should end up with ?Hº = 572 kJ/mol right??
March 25, 2017

Chemistry
Given ?Hºrxn = -1670 kJ/mol for 2Al(s) + (3/2)O2(g) --> Al2O3(s), determine ?Hº for the reaction 2Al2O3(s) --> 4Al(s) + 3O2(g). I flipped Al(s) + (3/2)O2(g) --> Al2O3(s) to Al2O3(s) --> A(g) + (3/2)O2(s) and multiplied the molar values by 2. I ended up ...
March 25, 2017

Chemistry
Yes, I meant answer C.
March 24, 2017

Chemistry
Which of the following processes is endothermic? a) H2O (g) --> H2O (l) b) 3O2 (g) + 2CH3OH(g) --> 2CO2(g) + 2H2O(g) c) H2O (s) --> H2O (l) d) O2(g) + 2H2(g) --> 2H2O(g) I a guessing b, since energy has to go into the reaction for water to go from a solid to a ...
March 24, 2017

physics
Two small balls are attached to a rigid rod of mass 2.2 kg that is 6.0 m in length. The first ball has a mass of 2.25 kg and the second ball has a mass of 4.95 kg. (c) What is the moment of inertia of the rod when it spins around its center of mass?
March 23, 2017

Chemistry
So, essentially .6164 kJ/g --> kJ/mol .6165/24.31 = .0254 kJ/g
March 23, 2017

Chemistry
When .1625 g of Magnesium is burned in a bomb container that has a heat capacity of 3.03 kJ/ºC, the temperature increases by 1.252 ºC. How much heat (kJ/mol) is liberated during the burning of magnesium? Just want to make sure I am doing this correctly: q = ms?T q...
March 23, 2017

Chemistry
Calculate the enthalpy of formation if 78.5 g of carbon dioxide in the following reaction: C(s) + H2O(g) --> CO2(g) Use the following equations: a) H2O(l) --> H2(g) + (1/2)O2(g): ?°f = +285.8 kJ/mol b) C2H6(g) --> 2C(s) + 3H2(g): ?°f = +84.7 kJ/mol c) 2CO2(g...
March 23, 2017

Chemistry
In which of the following reactions is work done by the system to the surroundings? A) 2CH3OH(l) + 3O2(g) --> 4H2O(l) + 2CO2(g) B) S(s, rhombic) + O2(g) --> SO2(g) C) 2AgNO3(s) --> 2AgNO2(s) + O2(g) D)4Fe(s) + 3O2(g) --> 2Fe2O3(s) My guess is B because according to...
March 23, 2017

Chemistry
Calculate the enthalpy of formation of carbon dioxide in the following reaction: C(s) + O2(g) -> CO2(g) Use the following equations: a) H2O(l) --> H2(g) + 1/2 O2(g): ?H° = +285.8 kJ/mol b) C2H6(g) --> 2C(s) + 3H2(g): ?H° = +84.7 kJ/mol c) 2CO2(g) + 3O2(g) --&...
March 22, 2017

Math
Yes, this is what I thought!! Im so confused unless this is a trick question.
March 22, 2017

Math
Which of the following equivalences is true? x^2 ? 0 ? (x+1)^2 ? 1 x^2 ? 0 ? x^2+1 ? 1 x > 0 ? x^2 > 0 x^2 > 0 ? x^2+1 ? 1 x ? 0 ? x^2 ? 0
March 22, 2017

Maths, dynamics
A particle moves such that its velocity at time t is given by v =5t^5i + 4t^5j + t^3k. If its position x at time t = 0 is given by x ( 0 ) = i + 2j, what is the position of the particle at time t?
March 21, 2017

Maths, dynamics
A particle of mass 45 kg moves in a straight line such that the force (in Newtons) acting on it at time t (in seconds) is given by 225t^4-90 t^2-225. If at time t = 0 its velocity, v , is given by v ( 0 ) = 2, and its position x (in m) is given by x ( 0 ) = 5, what is the ...
March 21, 2017

Social Studies
C D A
March 20, 2017

Chemistry
The enthalpy of combustion of butane C4H10 is described by the reaction: C4H10(g) + (13/2) O2(g) -> 4CO2(g) + 5H2O(g) ?H°rxn = –2613 kJ/mol Given the following enthalpies of formation: ?H°f[CO2(g)] = -393.5 kJ/mol ?H°f[H2O(g)] = -241.8 kJ/mol Calculate the ...
March 18, 2017

Chemistry
What is the final temperature when 180.0 mL water at 101.3 C is added to 93.1 mL of water at 65.5 C?
March 17, 2017

Chemistry
A gas expands its volume from 4.7 L to 8.9 L at constant temperature. Answer the following: a) If the gas expands against vacuum conditions, calculate the work (in joules) done by the gas. b) Calculate the work done (in joules) by the gas if it expands against a constant ...
March 17, 2017

World History
Do you finish the test?
March 15, 2017

Chemistry
Which statement is always true if ?U sys is always negative? a) q = w b) +q>–w c) -w> +q d) +w>-q
March 11, 2017

Chemistry
Identify which of the following changes is exothermic. a) liquid water boils to steam b) liquid water freezes to give ice c) ice melts to give liquid water d) liquid water increases in temperature from 35 C to 45 C
March 11, 2017

Chemistry
what volume of oxygen is needed to react to complete reaction and to form 5cm of so3?
March 11, 2017

Accounting Help (with answers for checking)
Ben Guslists, vice-president of sales, has recommended adding a new product line. A market study and cost analysis show that the new line should yield the following annual results: New Sales $2,800,000.00 Cost of Sales $1,600,000.00 Operating Expenses $200,000.00 Total ...
March 10, 2017

Algebra
When kevin commuted to work one morning, his average speed was 45 mph. He averaged only 30 mph for the return trip because of an accident on the highway. If the total time for the round trip was 50 min determine the distance between his place of work and his home.
March 6, 2017

Math
the ratio of A to B is 3:8 and the ratio of B to C is 1:6 what is the ratio of A to C
March 6, 2017

Chemistry
Ross pours water at 6.0 C into a container with a pressure of 23. torr. He then boils the water to a temperature of 34 C. The volume changes to 18. mL and pressure to 78. torr. What was the initial volume of the water?
March 6, 2017

Chemistry
When a person got onto an airplane, she brought with her a half-full 1.0000 L aluminum water bottle that was closed inside the airport at standard pressure and a temperature of 26.000 C. After the plane takes off and climbs to 36,000. feet, the cabin pressure is at 0.82000 atm...
March 6, 2017

Algebra
For the equation -4y =8x what is the constant variation? -4 -2 1 2 Is it -2?
March 5, 2017

Chemistry
Which pair of reactants will not react? Au(s) with Hg^2+ (aq) Pt^2+ (aq) with Au(s) Ag(s) with Cu(s) Au(s) -> Au^3+(aq) + 3e- Hg(s) -> Hg^2+(aq) + e- Pt(s) -> Pt^2+(aq) + 2e- Cu(s) -> Cu^2+(aq) + 2e- My guess is all of them, but I am not entirely sure.
March 5, 2017

Chemistry
Using the following portion of the activity series for oxidation half-reactions, determine which element(s) can react with an acid to produce H2 gas. Co(s) ? Co^2+ (aq) + 2e- Ni(s) ? Ni^2+ (aq) + 2e ? Sn(s) ? Sn^2+(aq) + 2e - H2 (g) ? 2H+ (aq) + 2e ? Cu(s) ? Cu^2+ (aq) + 2e ? ...
March 5, 2017

History
That was really rude. I came on here because I just needed some help because my class is hard and I've read my materials. I will be giving this website a bad rating and never using it again. You could give me a link that I could read to help me understand everything but ...
March 2, 2017

History
Which type of rule allowed western governments to run colonies themselves? A: Direct rule B: indirect rule C: Sphere of influence D: protectorate I think it's c or d. I read my textbook but it all seems like they are under some type of government.
March 2, 2017

math
ahh
March 1, 2017

math
25 + 20 + 18 + 17 = 80 27 (2) seaters = 54 spots to sit. 80 students.. 54 spots to sit. :/ Not sure how that would work out
March 1, 2017

math
And std 1 , 2 ,3 and 4 are the different classrooms?
March 1, 2017

math
two*
March 1, 2017

math
What's "(2) seaters"? Is it something that seats too people? I'm confused..
March 1, 2017

math
30% of 5,000 is 1,500. 60% of the 1,500 kids are boys. That means 40% of 1,500 kids are girls. 40% of 1,500 is 600. There are 600 girls in the town.
March 1, 2017

art
Yes I agree.
March 1, 2017

Math
Does anyone have the answers for the Penn Foster Math for Business and Finance proctored exam? 060497
February 28, 2017

health
I think 1. is A and 2. is B or C So yeah I agree with you.. sadly I don't know between B and C either..
February 27, 2017

social studies
what was major cause of problems with the sharecropping system
February 26, 2017

Trig identies, Calculus
Use the identities cos^2 x + sin^2 x =1 and cos2x=cos^2 x -sin^2 x to show that cos^4 x -sin^4 x = cos2x Im not sure how, I can solve my problem with half angle identities but im not sure where to start with this.
February 25, 2017

matrix, linear transformations
To add this is the matrix multiplication im doing to get the answer: {{4,0},{0,6}}*{{0,1},{1,0}}*{{1,2},{0,1}
February 25, 2017

matrix, linear transformations
Morning, Bit confused: I have been given the following: g(x,y)=(4x,6y) h(x,y)=(x+2y,y) k(x,y)=(y,x) and ive got the following matrix for each of them: g={{4,0},{0,6}} h={{1,2},{0,1}} k={{0,1},{1,0}} So ive been asked to prove the linear transformation f=k.h.g has the matrix: A...
February 25, 2017

Math Derivatives
Find f''(2) of function f(x)=xsin(pi/x)
February 22, 2017

math help asap
For the data in the table does y vary directly with x? if it does write an equation for the dorect variation. x;y 10,15 16,24 20,30 a:yes; y=1.5x b:yes;y=2x c:yes;y=x+5 d: y does not vary directly with x if you are from connections and know any other answers/know to help with ...
February 22, 2017

Differential equations,Calculus
Thanks Steve.
February 22, 2017

Differential equations,Calculus
Just to add, by doing what I described above my answer for c would be the same value as for k (i.e 3.9 or 5/4pi) so my particular solution would be. t=k(-1/r)+5/4pi
February 22, 2017

Differential equations,Calculus
So I have the following differential equation. The general solution I have is: t=k(-1/r)+c I now need to find the particular solution when t=0 and the radius (r) = 1cm. So k is a constant which is approx 3.9 (5/4pi) So for the particular solution im really just plugging in the...
February 22, 2017

Algebra
1. The perimeter of a rectangle is 78 cm. The length is 3 greater than twice its width. Find the dimensions.
February 21, 2017

chemistry
Confused on how to find the reactants in these two compounds Ba(OH)2 (aq) + I2Zn (aq) -> ?? Additionally, I am not really sure how to find the ionic equation for this.
February 21, 2017

Differential equation, calculus
Thanks, just testing out methods and got carried away!
February 21, 2017

Differential equation, calculus
Hiya, Dt/dr =k/r^2 Is this directly solvable or do I need to separate variables. I've got t=-k/r+c from the former and something along the lines of r^3=kt+c from the latter. Think I'm doing it all wrong. Thanks
February 21, 2017

Biology
What is the path that electrons take in C3 photosynthesis?
February 20, 2017

chemistry
Balance the following chemical reaction and determine the number of moles of HI produced when 2.33 moles of H2(g) are consumed in the following chemical reaction: ___H2(g) + __I2(g) -> ___HI (g)
February 19, 2017

Chemistry
Hello, I was hoping that I could get some help with calculating the mass needed to completely react with this question. In the following chemical reaction between H2 and N2 to produce NH3, what is the mass of N2 needed to completely react with 0.65 g H2 to produce 3.68 g of ...
February 19, 2017

Differential equation
A spherical balloon remains spherical as it is slowly inflated. The radius of the balloon r (in cm) at time t (in seconds) satisfies the differential equation. Dr/dt = k/r^2 where k is a positive constant. When the radius is 3 cm, the radius is increasing at the rate of 5/36pi...
February 19, 2017

social studies
The World May Never Know: Thank you so much!
February 15, 2017

Social Studies---Please Help!
The answer is D
February 8, 2017

Accounting
Cupid Co. has total assets of $600,000 and its liabilities are equal to two-thirds of its total assets. What is the amount of Cupid Co.'s Owner's Equity? Please explain how you got this answer.
February 7, 2017

Math - limits
Let f(t)=sint where t is the measure of the angle in degrees. Thus f is the sin function on your calculator if you select degree mode. Then: lim(t->0)(f(t)/t)= (Your answer will be a real number.)
February 7, 2017

History
How did the issue of states' rights influence South Carolina's decision to secede? this is a short answer, so there are no options. please help. thanks in advance :)
February 7, 2017

History
How did the results of the presidential election in 1860 influence South Carolina's decision to secede? there are no choices, it is a short answer. please help :)
February 7, 2017

Math
Which ordered pair would be plotted by starting from the origin and moving 0.25 units left and then 3 units up? A) (3, -0.25) B) (0.25, -3) C) (-0.25,-3) D) (-0.25, 3)
February 7, 2017

Math
How do I shift f(x)=x^2+sinx 3 to the right and 7 up?
January 31, 2017

Algebra
Name a pair of complementary angles A- anglesign 1 and anglesign 4 B- anglesign 1 and anglesign 6 C- anglesign 3 and anglesign 4 D- anglesign 4 and anglesign 5 I think it's D
January 30, 2017

american goverment check answers
yup the answer is D. 2 is B and C and 3 is D btw :)
January 27, 2017

Math
Ah okay. Thanks!
January 26, 2017

Math
5!=120 1/120= 0.0083 but the options are 0.1 0.054 0.0167 Impossible to determine Am I missing something?
January 26, 2017

Math
5 students are randomly seated along the side of a table. What is the probability that they are seated in order of age?
January 26, 2017

Math
Ms. Sue read the question wrong. Set a variable for floor value. x*1.95=184.49 x=184.49/1.95
January 26, 2017

Physics
You drop a rock into a deep well. You can't see the bottom of the well but you can hear the impact after T seconds. Suppose the speed of sound is c feet per second and the depth of the falling rock at time t is gt^2/2 feet. Compute the depth d of the well. Your answer will...
January 26, 2017

SS
The correct answer was D from monarchy to democracy. I took the same quiz, the answers are: 1. A 2. C 3. A 4. D 5. D
January 24, 2017

american goverment check answers
1. A 2. C 3. C and D 4. C just took the quick check 100% :)
January 23, 2017

math adv funcrions
2sin5xcos4x-sinx=sin9x Can u do this without triple angle formula and how
January 23, 2017

Social Studies
You work for President Lula's government. You are most likely to support A) tax cuts for corporations.**** B) privatization of industry C) redirection of oil wealth to provide social services. D) budget cuts to education and health care
January 22, 2017

Social Studies
My textbook? My textbook is online and it didn't say anything about Roman Catholicism.
January 22, 2017

Social Studies
Brazil's culture reflects what unique aspect of its colonial history? A) its Roman Catholic missionary roots B) its ties to the West African slave trade C) its rule and settlement by the Portuguese D) its peaceful blending of native and European peoples
January 22, 2017

Social Studies
Okay thank you!
January 21, 2017

Social Studies
Wealth disparity in Brazil results mostly from? A)unequal land distribution.**** B)insufficient arable land. C)lack of oil and mineral resources. D)emphasis on cash crop exports.
January 21, 2017

Physics
A very long uniform line of charge has charge per unit length 3.70 µC/m and lies along the x-axis. A second long uniform line of charge has charge -2.20 µC/m per unit length and is parallel to the x-axis at y = 0.400 m. What is the net electric field (magnitude and...
January 19, 2017

English
i also just took it and "whatever"'s answers are correct.
January 18, 2017

English
can confirm these are 100%
January 18, 2017

English
Those answers above are right
January 18, 2017

Geometry
The base of a right triangular prism is a right isosceles triangle whose equal sides measure 25 cm each. The volume of the prism is 0.075 cubic meters. Find the height of the prism
January 10, 2017

Social studies
Nope Unknown is 100% correct Mrs.Sue looks like the prankster XD
January 10, 2017

language arts
@Cam'Ron KILL YOURSELF
January 6, 2017

am I right ? or no?
Which equations represent exponential growth? Which equations represent exponential decay? Drag the choices into the boxes to complete the table. Exponential Growth: y=4000(1.0825)^t ,y=12,000(0.72)^t , y=8000(0.97)^t , Exponential Decay: y=1700(1.25)^t , y=240(1/2)^t , y=1.5(...
January 4, 2017

Algebra 1- Urgent
The price of products may increase due to inflation and decrease due to depreciation. Derek is studying the change in the price of two products, A and B, over time. The price f(x), in dollars, of product A after x years is represented by the function below: f(x) = 0.69(1.03)x ...
December 17, 2016

Algebra 1- Help please
Belinda wants to invest $1000. The table below shows the value of her investment under two different options for three different years: Number of years 1 2 3 Option 1 (amount in dollars) 1100 1210 1331 Option 2 (amount in dollars) 1100 1200 1300 Part A: What type of function, ...
December 17, 2016

Algebra 1 Please help
f(n) = 8(1.05)^n, sorry
December 17, 2016

  1. Pages:
  2. 1
  3. 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. 7
  9. 8
  10. 9
  11. 10
  12. 11
  13. 12
  14. 13
  15. 14
  16. 15
  17. Next>>

Post a New Question