Saturday

December 20, 2014

December 20, 2014

Total # Posts: 678

**Math**

Write the sum (in sigma notation) 1 + 3/2 + 2 + 5/2 + 3 + 7/2 + 4 Sigma notation?
*December 15, 2014*

**Science one question!**

Explain how gravitational, electrical and magnetic force act on a maglev train? I just need help on magnetic thanks!
*December 2, 2014*

**Chemistry**

Thank you DrBob222. I really appreciate your help.
*November 27, 2014*

**Chemistry**

I don't know how to do this question, or even start it. Please Help. 2 kg copper kettle (specific heat capacity 0.385j/gC) has .0500 kg of water at 20C. How much heat is needed to raise the temperature of the kettle and content to 80C?
*November 27, 2014*

**math probability**

How many three digits codes (single digits 0-9) are possible part A is codes must exceed value of 400 i think answer is 400 multiply 10 multiply 400 or 400x400x400 as three digits
*November 14, 2014*

**math probability**

In box containing marbles 1-75, how many ways A) first marble are chosen Answer, i think 1/75 Part B) two marbles are chosen i think answer are inconclusive Part C is ball with number 37 is chosen i think answer is 1/74
*November 14, 2014*

**math probability**

A box has ten dollars, one is five dollar and four of one dollars. If two bills are chosen at random without replacement, find probability of getting A) amount of valued fifteen dollars B) amount of twelven dollars... is it 4 from 19-15 for A and 7 from 19-12= 7?
*November 14, 2014*

**Math**

theta = 16 pi / 5 How to find the reference angle in radians? Do i have to use degree to pi conversion?
*November 7, 2014*

**sentence structure**

The subject are the children. The predicate is what is being told about the subject, in this case the predicate is what is being said about the children. So; Subject: children Predicate: waiting
*November 7, 2014*

**Math Calc**

Solve the equation 7sin(theta)=6 for theta, an angle in the right triangle Round your answer to three decimal places. Theta = 58.998? I don't think I got this right.. Please help
*October 31, 2014*

**statistics**

Assume that the readings on the thermometers are normally distributed with a mean of 0 degrees and standard deviation of 1.00 degrees C. A thermometer is randomly selected and tested. Draw a sketch and find the temperature reading corresponding to p subscript 99, the ...
*October 30, 2014*

**math**

Jenna says that no row or column contains products with only odd numbers. Do you agree? explain.
*October 27, 2014*

**Physics**

A 1200 kg car pulls a 510 kg trailer. The car exerts a horizontal force of 4040 N against the ground in order to accelerate. What force does the car exert on the trailer? Assume an effective friction coefficient of 0.160 for the trailer.
*October 25, 2014*

**chemistry**

H3PO4+3Ca(OH)2=Ca3(PO4)2=6H2O If 44.6g of Ca3(PO4)2 are formed in the above reaction, how many moles of H3PO4 must have been consumed?
*October 24, 2014*

**physics**

A long jumper leaves the ground at an angle of 24.4◦to the horizontal an data speed of 9.52m/s.How far does he jump?The acceleration due to gravity is 9.8m. What maximum height does he reach?
*October 23, 2014*

**Math**

6 rectangular sheets of paper with the demensions of o.5m and 0.8m, if they do not overlap what is the total area covered
*October 23, 2014*

**algebra**

(a+10)(a-10)/(a-10)(a+4) Simplify rational expressions
*October 21, 2014*

**Algebra**

From a survey of 100 college students, a marketing research company found that 45 students own ipods, 45 owned cars and 25 owned both cars and ipods. How man students owned either a car or an ipod (but not both) and how many do not own either a car or an ipod?
*October 17, 2014*

**english**

which of these is an example of direct characterization The students gasped at the teachers tremendous height Mr Lightner is cruel and is no friend to animals Sasha hid the toys Melissa plays tennis I chose the 3rd one
*October 5, 2014*

**English**

Identify the common noun in the sentence Every year Black Middle School host its annual Spring Fling I thought it was year maybe
*October 5, 2014*

**AP European History**

I have to write an essay and the instructions are Analyze the economic, technological and institutional factors responsible for Western Europe’s domination of world trade from 1650-1800 I must have 2 examples for each of the three so far I have Economic: Mercantilism ...
*October 5, 2014*

**English**

Thank you!
*October 5, 2014*

**English**

I think the first one
*October 5, 2014*

**English**

Which of these is an example of direct characterization Treys voice remained calm as he shared the news Taya was well known for her good looks Marcus is shy and has difficulty speaking to a crowd
*October 5, 2014*

**Algebra**

Of 375 musicians some play only jazz band, some play only the marching band, some play both.If 250 play in the jazz band and 130 play in both, how many play in the marching band? My answer is 135
*October 4, 2014*

**Algebra**

It is travailing at 30 feet per second. Sorry
*October 4, 2014*

**Fraction**

One egg is 1/12 of a dozen. How many eggs is 3/4 of a dozen?
*October 2, 2014*

**Math**

A quart is one fourth of a gallon. Dan drank half a quart of milk. What fraction of a gallon did Dan drink?
*October 2, 2014*

**Math**

On what day in the year 1943 was the earth 300 000 minutes old? (give the month and day)
*October 1, 2014*

**Math**

Take the 9100 and add or subtract each of the numbers one by one. Ex 9100 + 1200 = 10,300 9100-900=8200 9100 + 1000 = 10,100 9100 - 800 = 8300 Add all the sums and divide by 4 = 9225
*September 29, 2014*

**Math**

Sorry Ms. Sue but I am confused does that include the 9100. I thought the want the average altitude should it be 925.
*September 29, 2014*

**Math**

Pat and Kelly went hiking in the mountains. They started at 9,100 ft. They climbed 1,200 ft the first day, descended 900 ft the second day, and climbed 1,000 ft the third day. On the fourth day they descended 800 ft. What was the average altitude at which they hiked?
*September 29, 2014*

**Physics**

This is a vector problem. A man starts at home and runs 5 miles north and then 5 miles in a direction 23 degrees south of west. Now he wants to go back home in a straight line. How far does he need to go and in what direction? so i found that the hypotenuse equals 5.4 miles ...
*September 23, 2014*

**English**

I have to write a 500-750 word essay using exemplification as a method of development. This is my first draft. Can someone proof read this for any errors and help let me know the areas that I need to work on. Do you think this is a good Exemplification Essay? my instructors ...
*September 16, 2014*

**English**

For one of my homework assignments I had to read 3 different narratives. I then had to choose one of the narrative essays that I had read and explain what the point is with that essay. Can you please read over my answer and let me know if their are any grammatical errors that ...
*September 16, 2014*

**Physics**

A body weighing 980N is moving with constant speed of 5 m/s on a horizontal surface. The coefficient of sliding friction between the body and the surface is 0.25. What horizontal pull is necessary to maintain the motion?
*September 10, 2014*

**English**

Can someone please help me proof read my paper and help me to know where my errors are and how I can better this paper? Is this good for a descriptive essay? Is their something I should elaborate more or less on? Are my paragraphs ok or do I need to shorten them? Any and all ...
*September 8, 2014*

**English**

I see it now; a narrative essay would explain/describe the complete process of childbirth. A descriptive essay would elaborate on maybe one aspect of childbirth, such as the contractions more in-depth; overly describing the contractions in every way, shape or form. Is their ...
*September 7, 2014*

**English**

I have to write a "Descriptive essay" for my composition class and I need help proof reading my essay. This is the third draft I have done. I had to cut out over 400 words. The essay can be no more than 750 words. That is exactly how many I have right now. I have ...
*September 7, 2014*

**math**

Zoe had a board 5 1/4 feet long. She cut off a piece. Now the board is 3 5/6 feet long. How long was the piece she cut off?
*September 5, 2014*

**English**

Look at the following sentences, which use the passive voice. Then rewrite each sentence in the active voice, and decide which version you prefer and why. 1. Mistakes were made. a. I made mistakes. 2. Musical legends such as Ray Charles, Billie Holiday, and Johnny Cash have ...
*September 3, 2014*

**English**

Revise the following sentences as needed to create pronoun-antecedent agreement and to eliminate the generic he and any awkward pronoun references. 1. While shopping for a new computer for school, I noticed that a laptop costs much less that they used to. a. While shopping for...
*September 3, 2014*

**English**

Sorry I forgot my answer to question 5. 5. In my previous job, I sold the most advertising spot and was given a sales excellence award. a. In my previous job, I was given the sales of excellence award for selling the most advertising spots.
*September 2, 2014*

**English**

34.1 Revise the following sentences to eliminate unnecessary shifts in tense, mood, voice, or person and number and between direct and indirect discourse. 1. The greed of the 1980s gave way to the occupational insecurity of the 1990s, which in turn gives way to reinforced ...
*September 2, 2014*

**HISTORY**

If you were one of the new immigrants who arrived in America in the 1880s, it's most likely that you would have been A. German and Lutheran. B. Italian and Catholic. C. Swedish and Protestant. D. Irish and Protestant. I AM BETWEEN A and D can you please help me ?
*August 28, 2014*

**Physics--check answers please**

1. Resolve an acceleration vector of 40m/s^2 [25 degrees E of S] into its components For this I got 17 as my x component and 36 as my y component 2. A player is positioned 35m [40 degrees W of S] of the net. He shoots a puoock 25m [E] to a teammate. What second displacement ...
*June 23, 2014*

**Math**

Hi, I need someone to check my work and I have a question. Polygon: pentagon Number of sides: 5 Smallest number of interior triangles: 3 Now, here's my question: Sum of degrees of the interior angles: ___*180=_____ degrees
*June 4, 2014*

**math**

Stuart estimates that he will need $25000 to set up a small business in 7years. Answer A=$10,926.92 Answer B=$14,073.08
*June 3, 2014*

**updated question**

I am given this data table: Time After Consumption (min): 30, 60, 90, 120, 150, 180 Amount of Codeine in Blood (mg): 27.0, 23.5, 21.2, 18.7, 16.6, 14.5 Question: I created a scatter plot of the data. Would y=3.5/30x+30.5 be an equation to model the amount of codeine in the ...
*June 2, 2014*

**Calculus Help**

I am given this data table: Time After Consumption (min): 30, 60, 90, 120, 150, 180 Amount of Codeine in Blood (mg): 27.0, 23.5, 21.2, 18.7, 16.6, 14.5 Question: I created a scatter plot of the data. How would I determine an equation to model the amount of codeine in the ...
*June 2, 2014*

**Math**

Draw a concave quadrilateral that is not an arrowhead
*May 28, 2014*

**Question**

what the condition in which a child is born with a third copy of one of its 23 sets of chromosomes
*May 24, 2014*

**biology Help **

The fertilized egg undergoes cell divisions that form a ball of cells during (A)__________. During (B)__________, the endoderm, ectoderm, and mesoderm form. All the tissues of the adult body will come from these three germ layers. Differentiation is the process where cells are...
*May 19, 2014*

**Physics**

A 2kg begins at the top of a 1m high frictionless, inclined plane on top of a 1.5m high table. If it is loaded onto a spring with spring constant 50N/m and compressed 10 cm from equilibrium and then released, how far from the edge of the table will the block land?
*May 9, 2014*

**Physics**

A cannonball is hot straight up from the edge of a cliff with an initial velocity of 30m/s. A second cannonball is shot straight downward from the edge of the same cliff with an initial velocity of -30m/s. How do the speeds of the two cannonballs compare when they reach the ...
*May 8, 2014*

**Physics**

Peter is shooting arrows at a target with a bow. The target is 10m above the arrows launch point and some distance from Peter. If the arrows are shot with initial velocity Vo at 60 degrees with respect to the ground, then they will hit the target at the highest point of their ...
*May 8, 2014*

**Physics**

I got the wrong answer. My answer key says the answer is 7m/s. t = sqrt(20/9.8) = 1.428 d = 1/2(9.8)(1.428)^2 = 10 d*t = 14.28 What am I doing wrong?
*May 8, 2014*

**Math**

Circle the angle(s) that could never be the smallest angle of a triangle. 8 degrees 47 degrees 88 degrees 91 degrees
*May 7, 2014*

**chemistry**

Oh ok, I see what I did wrong, I switched the masses for Electron and Neutron. Ok now we're on the same page. So then to get kg you multiplied 0.813986 amu by 1.66054x10-27 kg = 1.3516563E-27 kg. Then, plug it into the equation E=mc^2 I got 1.216E-10 . Then divide that by ...
*May 2, 2014*

**chemistry**

or no it equals to 12.29. Then i divided it by 1000 because I thought that's how I would get kg
*May 2, 2014*

**chemistry**

No it seems we aren't. So this is what I did to find the P E N of Rb #protons=#electrions=37 (from the periodic table) Neurtrons= 87-37=50 with that I multiplied by their masses. Added them together to get 74.6176. Then I did 86.909187-74.6176 = .01229
*May 2, 2014*

**chemistry**

How much energy in MeV is released to form one atom of 87Rb from protons, electrons, and neutrons if the nucleus has a mass of 86.909187 amu? The masses of the proton, electron and neutron are 1.00728 amu, 0.000549 amu and 1.00867 amu, respectively. 1.602x10-13 J = 1 MeV; 1 ...
*May 2, 2014*

**Algebra - HELP!!!**

Would 21 be negative 10.35, and positive 1.35 Would 20 be negative 11.56 and positive 1.56
*April 22, 2014*

**Algebra - HELP!!!**

I can't! the formatting is odd.
*April 22, 2014*

**Algebra - HELP!!!**

For 20 and 21 are the x values in both negative and the y values positive?
*April 22, 2014*

**Algebra - HELP!!!**

negative 16t to the second power plus 85. :)
*April 22, 2014*

**Algebra - HELP!!!**

– 16 t^2 + 85 (sorry for having to repost so many times)
*April 22, 2014*

**Algebra - HELP!!!**

–16t^2 + 85
*April 22, 2014*

**Algebra - HELP!!!**

Here is a better copy of 11: 11. If an object is dropped from a height of 85 feet, the function h(t) = –16t^2 + 85 gives the height of the object after t seconds. Approximately, when will the object hit the ground? (1 point) 85.00 seconds 69.00 seconds 0.33 seconds 2.30 ...
*April 22, 2014*

**Algebra - HELP!!!**

Can someone help me and check these? 1. Graph the function and identify the domain and range. y = –.5x² (1 point)graph *domain: (–∞, ∞) range: [0, ∞) graph domain: (–∞, ∞) range: (–∞, 0] graph domain: (–∞...
*April 22, 2014*

**Chemistry**

I had conducted an experiment to figure out the percent by mass of baking soda in a mixture by titration. I had to standardize 1.0M HCl. Through the standardization process and the titration curve of the primary standard and the HCl, the molarity has to be found, but is this ...
*April 13, 2014*

**Chemistry**

The overall hydrogen burning reaction in stars can be represented as the conversion of four protons to one alpha particle. Use the data for the mass of H-1 and He-4 to calculate the energy released by this process.
*April 10, 2014*

**Chemistry**

years
*April 10, 2014*

**Math**

I get a black strip every 10 days. A white strip every 20 days, and a red strip every 21 days. I just got all 3 strips. How long 'till I get all of them again on the same day?
*April 9, 2014*

**Science**

A gas sample in a sealed vial originally at 0.6 atm and 300 K, was heated to 450 K. What other property of the gas has changed? What is the value of this property after heating?
*April 7, 2014*

**chemistry**

A gas sealed vial originally at 0.6 atm and 300 K, was heated at 450 K. What other property of the gas has changed? What is the value of this property after heating?
*April 7, 2014*

**chemistry**

calculate the molar weight of Freon-II, of 8.29 liters of its vapor at 200 degrees celcius and 790 mm Hg has a mass of 30.5 g.?
*April 7, 2014*

**Calculus**

Determine whether the series is convergent or divergent. If it is convergent, find its sum. If it is divergent, enter NONE. sum from 1 to infinity of (5^n+4^n)/20^n It is convergent, but I do not know how to find the sum.
*April 3, 2014*

**Calculus**

Determine whether the series is convergent or divergent. If it is convergent, find its sum. If it is divergent, enter NONE. sum from 1 to infinity of 1/e^2n. It is convergent, but I do not know how to solve for the sum.
*April 3, 2014*

**Chemistry**

How does dissolved CO2 in distilled water affect the accuracy of the determination of a NaOH solution's concentration? How is the term acid anhydride applied here? I know you had answered this already, but what if KHP is used to titrate the NaOH. In this experiment KHP was...
*March 29, 2014*

**Chemistry**

In this experiment NaOH is standardized to titrate it with vinegar so thtat the percent by mass of the acetic acid can be determined. How does dissolved CO2 in distilled water affect the accuracy of the determination of a NaOH solution's concentration? How is the term acid...
*March 29, 2014*

**Chemistry**

In this experiment NaOH is standardized to find out the percent by mass of the acetic acid in a sample of vinegar. A student had not allowed the NaOH pellets to dissolve completely before standardizing it with KHP, but when the student refilled the buret with NaOH to titrate ...
*March 29, 2014*

**Chemistry**

Titration was used to determine the molarity of acetic acid in vinegar. A primary standard solution of KHP was used to standardize the NaOH. 1. When performing this experiment, impure KHP was used to standardize the NaOH solution. If the impurity is neither acidic or basic, ...
*March 28, 2014*

**Chemistry**

I got think I got the following questions almost figured, but I just want someone to make sure that I am correct. 1) The whole experiment involves using the ideal gas law to predict the molar mass of an unknown liquid. The formula is molar mass of liquid = gR(0.0821)T(...
*March 28, 2014*

**CHEMISTRY**

The mass of an erlenmeyer flask is 78.639g and the mass of the flask and water is 327.039. If the density of water is 1 g/ml then what is the true volume of the flask? so i had subtracted the mass of just the flask from the mass of the flask and the water and got 248.4. Would ...
*March 28, 2014*

**mat116 algebra**

1-5x-4>-3
*March 21, 2014*

**statistics**

99% of men scored between -52.68 ,64.64 where did 95% of the values for weight relative to the ideal lie?
*March 19, 2014*

**Calculus**

Solve the initial-value problem. y'' - 2y' + y = 0 , y(2) = 0 , y'(2) = 1
*March 16, 2014*

**Calculus**

Solve the boundary-value problem. y'' + 5y' - 6y = 0 , y(0) = 0 , y(2) = 1
*March 16, 2014*

**Chemistry**

3. How does dissolved CO2 in distilled water affect the accuracy of the determination of a NaOH solution's concentration? The CO2 in the distilled water will create a more acidic solution which will affct the determination of NaOH solution's concentration? How is the ...
*March 11, 2014*

**chemistry**

Titration was used to determine the molarity of acetic acid in vinegar. A primary standard solution of KHP was used to standardize the NaOH. 1. When performing this experiment, impure KHP was used to standardize the NaOH solution. If the impurity is neither acidic or basic, ...
*March 11, 2014*

**Math**

Gold medalist, in freestyle skiing, Justine Duford-Lapointe, is trying to get to her hotel. She can travel north and east. The grid is a 5*5 followed by a 2*2, followed by a 8*8. How many ways can she take to her hotel?
*March 3, 2014*

**chemistry**

What is the product for Ni(s) + 2Na^+? I don't think this is possible. Am I wrong?
*March 2, 2014*

**Chemistry: Check my answers please!**

How would each of the following affect the Cr(VI) concentration determined in this experiment? Justify the answers with an explanation. In the experiment, absorption spectroscopy was used to obtain the concentration of Cr(VI) ions. 1) A student adds more standard solution than...
*March 2, 2014*

**Chem**

How would one be able to identify the lambda max of Cr(III) at a concentration less than 70ppm from a graph? I couldn't post the graph, but I don't understand how one would be able to do this? Can you please justify the answer with an explanation? I would want to know ...
*March 2, 2014*

**Chemistry**

How would one be able to identify the lambda max of Cr(III) at a concentration less than 70ppm from a graph? I couldn't post the graph, but I don't understand how one would be able to do this? The graph had the Chromium Absorbance Spectra of 70ppm for Cr(VI) and Cr(III...
*March 2, 2014*

**Chemistry**

How would one be able to identify the lambda max of Cr(III) at a concentration less than 70ppm from a graph? I couldn't post the graph, but I don't understand how one would be able to do this? The graph had the Chromium Absorbance Spectra of 70ppm for Cr(VI) and Cr(III...
*March 2, 2014*

**Chemistry**

How would each of the following affect the Cr(VI) concentration determined in this experiment? Justify the answers with an explanation. In the experiment, absorption spectroscopy was used to obtain the concentration of Cr(VI) ions. 1) A student adds more standard solution than...
*March 2, 2014*

**chemistry**

1) List a series of tests that would determine the order of activity (least active to most active) for Zn, Mn, and Ag. 2) What would be the reaction for the addition of excess OH- ions to Mg(NO3)2 and Cu(NO3)2? This is a complex ion forming reaction. Would the complete ionic ...
*March 2, 2014*

**Chemistry**

Why is a blank solution used in absorption spectroscopy? I know it is to nullify the reflection, refraction, and diffraction that occurs, but if the blank solution was a dilute solution rather deionized water, how would the concentration of Cr(VI)in a sample be affected?
*February 25, 2014*

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