Friday

July 31, 2015

July 31, 2015

Total # Posts: 284

**algebra 2 and trig**

The scores on a chemistry test are normally distributed. Approximately 95 percent of the scores fell between 78 and 92. What is the standard deviation for this distribution?
*May 18, 2015*

**Chemistry**

That is part of what I am confused about. This is all I have, plus the half eqs, [Sn]2+ + 2e- <-> Sn (s) V -0.13 and [Pb]2+ + 2e- <-> Pb (s) V -0.126
*May 4, 2015*

**Chemistry**

What is the value of the equilibrium constant at 25°C for the reaction between each of the following? (a) Sn(s) and Pb2+(aq) (b) Cr(s) and Cu2+(aq) I have been unable to get either and have spent the last two hours attempting it. I have been using the equation K = 10^(...
*May 4, 2015*

**Literature**

Thank you for your help.
*April 30, 2015*

**Literature**

Okay... Odysseus needs to reconnect to his family for the sake of his own identity and for the sake of his family and the people of Ithaca. Is this still too vague? Could this be considered an argument?
*April 30, 2015*

**Literature**

I have an 8-10 page final essay due concerning the Odyssey. I know my topic I want to use for my essay is FAMILY. The problem I having is forming an argumentative thesis. My question is... How would I begin to form an argumentative thesis? I continue to argue the importance of...
*April 30, 2015*

**Literature**

I am currently writing a compare/contrast paper discussing Flannery O'Connor's literary works and Dennis Covington's novel Salvation on Sand Mountain. My question is... Would I use present perfect or past perfect when discussing Dennis Covington's novel ...
*April 26, 2015*

**Biology **

Could you potentially use up all of your memory B and T cells for a specific antigen and become susceptible to that antigen again?
*April 13, 2015*

**Chemistry**

A professor wanted to set up a similar experiment as the one you performed in lab. The professor wanted to use Al(OH)3 in place of Ca(OH)2. Calculate how many mL of saturated Al(OH)3 solution it would take to titrate against 12.00mL of 0.0542M HCl solution? The Ksp of Al(OH)3 ...
*April 8, 2015*

**Chemistry**

Thank you!! I got 15.6%!
*April 6, 2015*

**Chemistry **

Instead of using ratios for back titrations we can also use molarities if our solutions are standardized. A 0.188g sample of antacid containing an unknown amount of triprotic base Al(OH)3 was reacted with 25.0mL of 0.101M HCl. The resulting solution was then titrated with 10....
*April 6, 2015*

**Chemistry**

Instead of using ratios for back titrations we can also use molarities if our solutions are standardized. A 0.188g sample of antacid containing an unknown amount of triprotic base Al(OH)3 was reacted with 25.0mL of 0.101M HCl. The resulting solution was then titrated with 10....
*April 3, 2015*

**Chemistry**

1. Imagine you have a saturated solution of Ca(OH)2, at equilibrium, that has some undissolved Ca(OH)2 precipitated on the bottom of the test tube. If you add an additional scoop of Ca(OH)2 to the solution will concentration of [OH-] in the solution (increase, decrease, or be ...
*March 16, 2015*

**Chemistry**

.0955molacid*.030L weak acid= .002865 mol acid/.1233 mol base= .02325 L base/2=11.62mL I got confused once I found my moles of acid, did I finish it correctly?
*March 11, 2015*

**Chemistry **

Calculate the volume at which pH = pKa if 30.00mL of weak acid with a concentration of 0.0955M is titrated against a strong base with a concentration of 0.1233M.
*March 11, 2015*

**Chemistry **

Hydrogen sulfide decomposes according to the following reaction, for which Kc = 9.30 10-8 at 700°C. 2 H2S(g) 2 H2(g) + S2(g) If 0.46 mol H2S is placed in a 4.6 L container, what is the equilibrium concentration of H2(g) at 700°C? So I thought that by using ice H2 would...
*March 9, 2015*

**Chemistry**

￼f=e^(-Ea/RT) f=e^(-151.0/(8.314e-3 x 292)
*March 4, 2015*

**Chemistry**

Never mind! I didn't change my R to kJ
*March 4, 2015*

**Chemistry **

At 19.0°C, what is the fraction of collisions with energy equal to or greater than an activation energy of 151.0 kJ/mol? I got 1.06 which wasn't right
*March 4, 2015*

**Chemistry**

Thanks!!
*February 17, 2015*

**Chemistry**

If all the H2O2 in 25mL of a 3% solution of H2O2 decomposed, calculate the diameter of a sphere that would contain the resulting O2 at 1 atm and 296K. I understand how to do the problem if I have moles but I am not sure how to get moles. I thought n=0.075moles because 3% ...
*February 17, 2015*

**Chemistry **

The coinage metals -- copper, silver, and gold -- crystallize in a cubic closest packed structure. Use the density of gold (19.3 g/cm3) and its molar mass (197 g/mol) to calculate an approximate atomic radius for gold. Work So Far: {[1/(19.3x197)]x.74}/6.022e23 =3.2319e18 [(3....
*February 3, 2015*

**ela**

is there another way of saying better understand? the snetence im trying to write is "imagery can also help the reader to better understand the poem thus the reader is able to ...(is it appropriate to write better understand again here?)"
*February 2, 2015*

**Honors Physics**

A canoeist is trying to paddle upstream in a river that has a velocity of 6.1 m/s. If he can paddle his canoe at a velocity of 6.2 m/s, will he make any headway? What will his velocity relative to the shore be?
*December 18, 2014*

**Chemistry**

So I got 251.5 Is that right? And thank you so much!
*December 14, 2014*

**Chemistry**

A gas is allowed to expand at constant temperature from 4.274L to 6.877L against an external pressure of 1.977 atm. If at the same time the gas absorbs 773 J of heat from the surroundings, what is Delta E for this process? (Note: Pay attention to units; 1 L atm = 101.325 J) I ...
*December 14, 2014*

**Chemistry**

A 500 mL flask has a measured volume of 586.0 mL. A 0.608g sample of an unknown vapor occupies the flask at 373K at a pressure of 0.981atm. Assume the vapor behaves ideally. What is the molecular weight of the unknown vapor?
*December 7, 2014*

**Chemistry**

A student analyzing 2.000g of Epsom Salt found that it contained 39.0% by mass water. What is the hydration number for this sample?
*December 7, 2014*

**Chemistry**

A student was isolating copper metal from a copper salt. If the student started with 1.255g of copper (II) sulfate how many grams of copper solid would you expect them to recover?
*December 7, 2014*

**chem/science **

A piece of an aluminum can was cut into small pieces. Then 0.422 g of the chips from the can was used to prepare potassium alum according to the procedure we used. Calculate the theoretical yield (in g) of potassium alum that could be obtained in the reaction. (Alum MW=474.41 ...
*November 24, 2014*

**please help! physics**

A 1200 kg car is moving at 95 km/h when the driver notices a deer down the road. He immediately moves his foot toward the brake pedal, taking only 0.50 seconds before the car starts slowing down. The brakes cause a net force of 2400 N (backwards) on the car for 2.0 seconds. ...
*October 21, 2014*

**Geology**

Hi, I am doing a geology course and I am really struggling with the topography graph. Currently, I am doing a test/quiz that involves me finding out what the contour interval is,the elevations of lines, and so on. I have tried looking back over the information but it is ...
*July 18, 2014*

**Math Homework: Check Answers**

Thank you!
*May 27, 2014*

**Math Homework: Check Answers**

1. Suppose you earned 8t - 3 dollars on Monday and 6t + 5 dollars on Tuesday. What were you total earnings? Simplify your answer. A) 2t + 2 B) 2t - 8 C) 14t + 2 D) 14t - 8 Answer: A 2. f^2 • f^4 A) (2f)^8 B) (2f)^6 C) f^8 D) f^6 Answer: D 3. 100^12/100^8 A) 100^12/8 B) ...
*May 27, 2014*

**Data Management **

Emilio has played ten rounds of golf this season. His mean score is 80 and standard deviation is 4. Assume Emilio's golf scores are normally distributed. a) Find the 95% confidence interval of Emilio's mean golf score b)Find the 95% confidence interval of Emilio's ...
*May 14, 2014*

**physics**

A square loop of wire of side 2.8 cm carries 3.0 A of current. A uniform magnetic field of magnitude 0.67 T makes an angle of 43° with the plane of the loop. (a) What is the magnitude of the torque on the loop? (b) What is the net magnetic force on the loop?
*May 13, 2014*

**physics**

What is the average linear speed of the Earth about the Sun? (The distance from the Sun to the Earth is 1.50 1011 meters. The orbital period around the Sun is 365.3 days.)
*May 12, 2014*

**Algebra 1**

Can you please check my work? A city planning committee surveys 100 people waiting at a bus stop about the expansion of the public transportation system. Is this an example of a: random sample, systematic sample, self-selected sample, convenience sample, bipartisan sample, or ...
*April 27, 2014*

**Algebra 1**

Will you please check my work? :) Choose ALL (if any) applicable terms for the events described, then calculate the probability of the events. Jason has a cube with colored sides: red, orange, yellow, green, blue and purple. 1. Rolling a red or a primary color. Choices: ...
*April 27, 2014*

**Algebra 1**

Thanks :)
*April 27, 2014*

**Algebra 1**

Can you please check my work and help me with the parts that I don't understand? For each event, choose the most appropriate term and solve the problem. 1. In a sweepstakes with nine hundred entries, the first winner selected receives the grand prize, the second receives ...
*April 27, 2014*

**Chemistry**

Write the balanced net ionic equations for the reactions of the halogens with copper metal. The halogens are oxidizing agents and the copper metal is a reducing agent. a) Bromine (Br2)+copper metal (Cu) b) Iodine (I2) + copper metal (Cu) Based on your observations and ...
*April 16, 2014*

**math**

What is 8% of 15?
*April 14, 2014*

**Math Polygons**

I am a closed shape made of 6 line segments. I have 2 angles less than a right angle and no right angles. What shape am I? Draw an example in the workspace.
*March 19, 2014*

**Chemistry**

a solution is prepared by dissolving 22.0g of NaOH in 117.0g of water. The NaOH solution has a density of 1.15 g/mL. what is the Molarity(M) of the solution.
*March 14, 2014*

**ALGEBRA! URGENT.**

1. What data are represented by the stem-and-leaf plot below? 3 | 7 8 9 4 | 1 3 7 5 | 2 4 Key: 4 | 1 means 41 a. 37, 38, 39, 41, 43, 47, 52, 54 b. 73, 83, 93, 14, 34, 74, 25, 45 c. 7, 8, 9, 1, 3, 7, 2, 4 d. 37, 38, 39, 14, 34, 74, 25, 45 2. Find the mode and the median of the ...
*March 5, 2014*

**Math Help? Check my answers.**

Ms. Sue? Can you help me with this?
*March 5, 2014*

**Math Help? Check my answers.**

Help please! :)
*March 5, 2014*

**Math Help? Check my answers.**

1. What data are represented by the stem-and-leaf plot below? 3 | 7 8 9 4 | 1 3 7 5 | 2 4 Key: 4 | 1 means 41 a. 37, 38, 39, 41, 43, 47, 52, 54 b. 73, 83, 93, 14, 34, 74, 25, 45 c. 7, 8, 9, 1, 3, 7, 2, 4 d. 37, 38, 39, 14, 34, 74, 25, 45 2. Find the mode and the median of the ...
*March 5, 2014*

**life orientation**

identify three study fields/career paths in order of preference and provide two reasons for each choice
*March 5, 2014*

**Molecular cell Biology**

The following chemicals have the indicated formula weights:Sucrose-342.3,Potassium dihydrogen phosphate(KH2PO40-136.09,Tris -121.14.You also have the following solutions made:20%SDS,5M NaCl,500mM EDTA.You have a 40%glycerol solution and 10X TBE.List the steps to make the ...
*January 18, 2014*

**Math**

If you can buy three raffle tickets for $5, how many tickets can you buy for $55? I need to know to different ways to solve this problem...
*November 13, 2013*

**physics**

I am having a really hard time figuring this question out, would somebody be able to help me? Imagine a giant dry-cleaner's bag full of air at a temperature of -35∘C floating like a balloon with a string hanging from it 12km above the ground. Estimate what its ...
*August 5, 2013*

**PreCalculus**

Could someone check these? I'm finding the magnitude for 5 and 6. 5. v=3i+j My magnitude is 3.16 6. v=2i+3j My magnitude is 3.61 For 22 and 23 I'm finding each specified vector or scalar. u=2i-5j, v=-3i+7j, w=-i-6j 22. v+w answer: -4i+j 23. u-v answer: 5i-13j
*June 10, 2013*

**PreCalculus**

I'm having trouble with these problems.. Could someone please explain how to find the domain of either of these functions? 3. f(x) =(x-2)/(x^2+6x+8) 7. g(x)= sqrt[(9)/(x+3)]
*June 10, 2013*

**English**

Jane Eyre. And I was leaning towards B because when I think of gothic elements I think of words like demonic, fiery, passion/love, mystery...
*May 26, 2013*

**English**

Which of the following is NOT a Gothic element in this novel? A. the low, demonic laugh in the hall at midnight B. strange laughter in a hidden, upstairs room C. the mysterious fire in Rochester’s bedroom D. the young Jane’s growing love for the older, moody ...
*May 26, 2013*

**Pre-Calculus**

I'm having trouble with this problem because I'm not sure what to do with the 1.. 21. (x-5)^2+(y+2)^2=1 (x-(5))^2+(y+2)^2= ???? center= (5,2) radius= ???
*May 10, 2013*

**Pre-Calculus**

I'm currently working with parabolas, and I'm not sure if I am doing this specific problem correctly.. 12. x= y^2-6y+6 y= -b/2a = 6/2(1)= 6/2= 3 x= (3)^2+6(3)+6 x= 33 y=3 (33,3) <--- what I graphed
*May 10, 2013*

**Pre-Calculus**

45. log b sqrt 7x 46. log b sqrt (3/y) Could someone please explain these?
*May 5, 2013*

**Pre-Calculus**

My book doesn't explain how to do these problems.. The examples they tell me to refer to have no relevance whatsoever. Any help would be appreciated. Use the power property to rewrite each expression. 17. log_3(x)^2 18. log_2(x)^5 19. log_4(5)^-1 20. log_6(7)^-2
*May 5, 2013*

**Pre-Calculus**

Thank you
*May 1, 2013*

**Pre-Calculus**

Could someone check my answers? 25. 32^(2x-3)=2 Answer- x= 8/5 26. 9^(2x+1)=81 Answer- x= 1/2 27. 1/4=2^3x Answer- x= -2/3 28. 1/27=3^2x Answer- x= -3/2 29. 9^x=27 Answer- x= 3/2 30. 32^x=4 Answer- x= 2/5 31. 27^(x+1)=9 Answer- x= 1/2 32. 125^(x-2)=25 Answer- x= 7/2 33. 81^(x-...
*May 1, 2013*

**Pre-Calculus**

I'm having problems understanding how to do these problems. 25. 32^(2x-3)=2 27. 1/4= 2^3x 29. 9^x=27 33. 81^(x-1)= 27^2x
*April 26, 2013*

**World Geography**

Cultures often develop along with science and ____________.
*April 23, 2013*

**Pre-Calculus**

Thank you for your help
*April 22, 2013*

**Pre-Calculus**

Could someone check my answers? 27. (16/9)^2/3 = 64/27 28. (49/25)^3/2 = 343/125 31. (-64)^2/3 = 8 32. (-8)^-4/3 = 1/16 or -1/16
*April 22, 2013*

**Excel**

Which option must be selected for all sheets within a workbook to be printed?
*April 16, 2013*

**Pre-Calculus**

Thank you both!
*April 10, 2013*

**Pre-Calculus**

I'm having trouble understanding how to do complex fractions.. My book doesn't explain it very well.. 12. (x+3/12)/(4x-5/15) 14. (2/x^2 + 1/x)/(4/x^2 - 1/x) 16. (1/y + 3/y^2)/(y + 27/y^2) If you could please explain how to begin the process I would appreciate it.
*April 10, 2013*

**World Geography**

For ques. #2 i have (b) is that correct Ms Sue?
*April 5, 2013*

**Math**

I have some white and black marbles in a box. There are 30 white marbles. There are 14 more white marbles than black marbles. How many black marbles do I have?
*April 5, 2013*

**Physics**

Nicole throws a ball straight up.Chad watches the ball from a window 5meters above the point where Nicole released it . The ball passes Chad on the on the way up, and it has a speed of 10m/s as it passes him on the way back down.Determine how fast Nicole threw the ball upwards
*April 4, 2013*

**trig**

An airplane pilot wishes to maintain a true course in the direction 250° with a ground speed of 400 mi/hr when the wind is blowing directly north at 60 mi/hr. Approximate the required airspeed and compass heading
*April 1, 2013*

**Math**

Gertrude and Ernest received their typing results. The results are normal and are shown below. Types Of Errors per Page Gertude - (Mean) 10 Standard Deviation- 1 Ernest - (Mean) 10 Standard Deviation- 4 Which statement is true? A. Gertrude probably has more pages with exactly ...
*March 30, 2013*

**Math**

Susan owns a chocolate store. She sells her chocolate by the gram and needs to compare the weights of two chocolate batches. She randomly selects 100 pieces from each batch. The distrubition of both samples are normal. Batch 1 - (Mean Weight) 56 grams Standard Deviation - 6 ...
*March 30, 2013*

**E**

Which is the best way to learn new material? A. Use techniques that appeal only to your preferred learning style. B. Review notes every day. C. Consistently study the same way. D. Use techniques that appeal to all three learning styles
*March 28, 2013*

**chemistry**

how many moles of O2 are contained in 6.53 L with 297 K and 6.6 atm
*March 26, 2013*

**Maths**

Ray and Roxanne leave from the same spot for their morning run. Roxanne runs due North at 8 km/h while Ray runs due East at 11 km/h. Find the distance and bearing of Roxanne from Ray after 20 minutes. Round your answers to one decimal place.
*March 19, 2013*

**Pre-Calculus**

How would I write this in exponential form? log(3)1/27= -3
*March 15, 2013*

**Social Studies**

what is 2
*March 11, 2013*

**Pre-Calculus**

*** final answer 3+5/4(3x-5) 3+5/12x-20
*February 27, 2013*

**Pre-Calculus**

Simplifying Complex Fractions [(x+3)/12] / [(4x-5)/15] [(x+3)/12] x [15/(4x-5)] (x+3)5/4(3x-5) (5x+15/12x-20)<-- final answer Did I do this right. If not could you please explain how to do it correctly
*February 27, 2013*

**science**

I think it is gravity but its probably wrong because I suck at science and I get like B's and hardly A's
*February 6, 2013*

**PHY 101**

An archer aims an arrow precisely horizontally over a large, flat field and lets it fly. At the same instant, the archer's watchband breaks and the watch falls to the ground. Does the watch hit the ground before, at the same times as, or after the arrow hits the ground? ...
*February 5, 2013*

**Pre-Calculus**

Could you please explain how to use a matrix (matrices) to solve a system of linear equations (two variables)? My book doesn't explain it in a way I can understand. Please and thank you.
*January 24, 2013*

**Pre-Calculus**

Thank you.
*January 22, 2013*

**Pre-Calculus**

Thank you so much.
*January 22, 2013*

**Pre-Calculus**

Solve by using the substitution method 1.x=-3y+4 and 3x+9y=12 3(-3y+4)+9y=12 -9y+12+9y12 0=0 x=-3(0)+4 x=4 Would there be infinite solutions or would it be (0,4)? 2. x=3y-1 and 2x-6y=-2 2x-6y=-2 2(3y-1)-6y=-2 6y-2-6y=-2 0=0 x=3y-1 x=3(0)-1 x=-1 Would there be infinite ...
*January 22, 2013*

**Pre-Calculus**

I have to use the substitution method to solve the system of equations. 4x-y=9 and 2x+3y=12 I worked this problem myself and could not find a possible solution. So I put that it is inconsistent. Is that correct? If not could you please help me?
*January 22, 2013*

**Pre-Calculus**

If you solve the following system of equations by substitution, which statement is true? x = z x - 2y + z = 6 2x + y - 2z = 1 A. You can substitute z for x into the second and third equations. B. You can substitute x for z into the second and third equations. C. Both methods ...
*January 22, 2013*

**Pre-Calculus**

What they did in their example is substitute x with one. I wasn't exactly sure why they were doing that so I came on here in hopes that someone could better explain it. Thank you!
*January 22, 2013*

**Pre-Calculus**

State the domain and range of the relation y = 2x + 3 My answer: y= 2x+3 y= 2(1)+3=5 domain: 1 range: 5 This is how my book showed me how to do it. I just wanted to make sure I did it right. If not could you please give me an example?
*January 22, 2013*

**Pre-Calculus**

Driving down Bald Mountain in Wyoming, Bob dean finds that he descends 1600 feet in elevation by the time he is 2.5 miles (horizontally) away from the high point on the mountain road. Find the slope of his descent (Hint: 1 mile = 5280 feet) After converting the miles to feet I...
*January 10, 2013*

**Spanish 2**

Ms.Sue thanks for sending it to the expert. And SraJMcGin thanks so much for taking a look at it and helping me. I'm going to speak with her. Thanks so much and sorry about the separated answers.
*January 3, 2013*

**Spanish 2**

I turned these in and my teacher said all my answers were wrong. I'm so confused because when I go through my chapter it says differently.Can someone please help?! A. Supply the correct form of the adjective. 1. rojo Hay una pluma _____ encima de la mesa. 2. alto La chica ...
*January 3, 2013*

**jmhs help**

B. An individual can learn using only his or her preferred learning style.
*December 13, 2012*

**Physics**

A force compresses a bone by 0.10mm. A second bone has the same length but twice the cross-sectional area as the first. By how much would the same force compress the bone?
*December 9, 2012*

**Science Help!**

A light beam has a frequency of 5 x 1015 Hz. What is its wavelength?
*November 13, 2012*

**Science**

1. A certain radar installation transmits electromagnetic radiation with a wavelength of 2.5 cm. What is the frequency of this radiation? 2. For the radar above, how many seconds will it take for a signal to reach an airplane 15 km away, and return to the radar installation
*November 13, 2012*