Thursday
December 8, 2016

# Posts by Ellen

Total # Posts: 220

Physics
My teacher didn't specify if 9.821 m/s^2 is the value of the North Pole. We don't have class this week because of Spring Break and it's due the morning we get back, so I can't ask him any questions. But I got C through F now, thank you!
March 4, 2011

Physics
Consider a pendulum of length 4.557 m. The acceleration of gravity is 9.832 m/s2 . a) What is its period at the North Pole? Answer in units of s. b) What is its frequency? Answer in units of Hz. c) What is its period in Chicago, where g = 9.803 m/s2? Answer in units of s. d) ...
March 4, 2011

Physics
A trapeze artist swings in simple harmonic motion with a period of 3.2 s. The acceleration of gravity is 9.81 m/s2 . Calculate the length of the cables supporting the trapeze. Answer in units of m.
March 4, 2011

Physics
A mass of 0.38 kg is attached to a spring and is set into vibration with a period of 0.22 s. What is the spring constant of the spring?
March 4, 2011

math (calculus)
A cap of a sphere is generated by rotating the region about the y-axis. Determine the volume of this cap when the radius of the sphere is 5 inches and the height of the cap is 1 inch.
February 13, 2011

math (calculus)
A cap of a sphere is generated by rotating the region about the y-axis. Determine the volume of this cap when the radius of the sphere is 5 inches and the height of the cap is 1 inch.
February 13, 2011

Physics
The hoover dam produces 2x10 to the 9 W of electricity. It is composed of 7x10 to the 9 kg of concrete. To produce 1 kg of concrete requires 1 MJ of energy. How much energy did it take to produce the dam? How long was the "energy payback time" for the dam? The area ...
February 2, 2011

Physics
the relationship between rotational speed and net force is direct right? and also can u say why it is direct
January 31, 2011

physical science 2
It takes 6 seconds for a stone dropped from rest to the bottom of a well,what is its final speed A; 6 meters/second B: 30 meters/seconds C: 36 meters/seconds D: 60 METERS/SECONDS A is incrrect
January 29, 2011

Physical Science 2
Ten seconds after starting from rest,a freely falling object will have a speed of about______ rn/s A: 10 B: 50 C: 100 D: 120 I know that the answer A is not correct.
January 29, 2011

physical science 2
A block is dragged at constant velocity in a straight line path across a level surface by force of 6 N. What is the friction between the black and the surface? a: 6 N B: less than 6 N C: More than 6N d: ZERO
January 29, 2011

physical science 2
the force required to maintain an object at a constant velocity in free space is equal to: b: the mass of the object. c: the force required to stop it. d zero
January 29, 2011

physical science
A kg ball of lead rests next to a 10 kg rock. which statement below is true:a:the lead ball and rock have the same amount of inertia,b:if the lead ball and the rock fell from the same height in a vacuum, the rock would hit the ground first because it is less massive,c: on the ...
January 29, 2011

physical science
a car traveling in a lage circlepasses by a motorcycle that is trveling in a straight line north to south.both of their speedometers read 10m/s.which statement is true; a: the car and motorcycle have the same speed ,but different velocities,b:the car and motorcycle have the ...
January 29, 2011

physics
The centers of a 6.0 lead ball and a 70 lead ball are separated by 8.0 . What gravitational force does each exert on the other? What is the ratio of this gravitational force to the weight of the 70 ball?
October 31, 2010

Chemistry
A calorimeter contains 21.0 mL of water at 14.0 degreesC. When 1.90 g of X (a substance with a molar mass of 70.0 g/mol) is added, it dissolves via the reaction X(s)+H_2O(l)reacts to make X(aq) and the temperature of the solution increases to 28.5degreesC. Calculate the ...
October 22, 2010

Chemistry
80.0 mL of water is initially at room temperature (22degrees C). A chilled steel rod at 2 degrees C is placed in the water. If the final temperature of the system is 21.2 degrees C, what is the mass of the steel bar? Specific heat of water = 4.18J/g(degreesC) Specific heat of ...
October 22, 2010

Chemistry
sorry. didn't mean to post twice
October 10, 2010

Chemistry
Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of Helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721 mmHg? Express your answer ...
October 10, 2010

Chemistry
Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721mmHg? Express your answer ...
October 10, 2010

Chemistry
Typically, when a person coughs, he or she first inhales about 2.50 L of air at 1.00atm and 25 degreesC. The epiglottis and the vocal cords then shut, trapping the air in the lungs, where it is warmed to 37 degrees C and compressed to a volume of about 1.70L by the action of ...
October 10, 2010

Chemistry
Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. For example, a solution of hydrogen peroxide,H2O2, can be titrated against a solution of potassium permanganate, KMnO4. The following equation represents the reaction: 2KMnO4(aq)+...
October 3, 2010

Chemistry
A volume of 50.0 mL of aqueous potassium hydroxide was titrated against a standard solution of sulfuric acid. What was the molarity of the KOH solution if 19.2 mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq) +H2SO4(aq)-» K2SO4(aq)+2H2O(l)
October 3, 2010

physics
A duck has a mass of 2.3 kg. As the duck paddles, a force of 0.07 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.26 N in a direction of 48° south of east. When these forces begin to act, the velocity of the duck is 0.15 m/s ...
September 23, 2010

math
i have 3 pints oil and 12 gallons of gas,each lawn mower uses 0.5 pints of oil and 1.5 gallons of gas. How many days can she mow lawns?
September 16, 2010

chemistry
Thank you! Now I am having problems with part e.
July 29, 2010

chemistry
I put in the wrong numbers for the second part.
July 29, 2010

chemistry
I can't figure out how to get the initial pH. Also, when I tried part B I used 21.0 mL*.100M=XmL*0.130 and it wasn't the correct answer.
July 29, 2010

chemistry
Consider the titration of 21.0 mL sample of 0.110 M HC2H3O2 with 0.130 M NaOH. what is the initial pH? what is the volume of added base required to reach equivalance point? what is the pH at 5.00 mL of added base? pH at one half o the equivalence point? pH at the equivalence ...
July 29, 2010

chemistry
Calculate the pH of the solution that results from the mixture. 170 mL of 0.12 M C2H5NH2 with 285.0 mL of 0.22 M C2H5NH3Cl.
July 28, 2010

chemistry
what is the pH of 0.15 M NaF?
July 28, 2010

chemistry
If 5.05mL of 0.1000 M NaOH solution is needed to just neutralize excess acid after 20.00 mL of HCl was added to 1.00 g of an antacid, how many moles of acid can the antacid counteract per gram?
July 27, 2010

chemistry
If 5.00 mL of HCl require 4.03 mL of 0.9581 M NaOH to just consume the HCl, what is the concentration of the HCl?
July 25, 2010

chemistry
need help with these problems: The concentration of glucose in blood is usually about 0.10% (w/v). If 7.0 L of blood are in an average man, how many grams of glucose are in his blood? To obtain the solute for 118 g of a 19.2% (w/w) solution of sugar we would weigh out ________...
July 20, 2010

chemistry
need help setting this problem up: The heat of fusion of water is 335 J/g. How much heat would be required to melt 10.4 g of ice?
July 20, 2010

Chemistry
The following reaction was monitored as a function of time: AB--->A+B A plot of 1/[AB] versus time yields a straight line with slope 5.2×10−2 . If the initial concentration of is 0.240M , and the reaction mixture initially contains no products, what are the ...
July 18, 2010

chemistry
The following reaction was monitored as a function of time: AB--->A +B A plot of 1/[AB] versus time yields a straight line with slope 5.2 x 10^-2 M*s. What is the value of the rate constant (k) for this reaction at this temperature?
July 17, 2010

ch102
The rate constant of a reaction at 30 was measured to be 5.7×10^-2. If the frequency factor is 1.2 x10^13 /s what is the activation barrier?
July 16, 2010

CH102
nevermind! figured it out
July 16, 2010

CH102
If a temperature increase from 18.0 to 34.0 triples the rate constant for a reaction, what is the value of the activation barrier for the reaction?
July 16, 2010

Chemistry
i tried that but it says its wrong
April 16, 2010

Chemistry
An air sample contains 0.038% CO2. If the total pressure is 764 mm Hg , what is the partial pressure of CO2?
April 16, 2010

Physics
thank you so so so much. the answer is .3626
March 24, 2010

Physics
A hollow plastic spherical bobber of mass 0.005 kg and volume of 50 cm3 floats on the surface of a lake supporting a submersed fishhook and a bait with a combined mass of 0.01 kg and a combined volume of 2 cm3. The density of water is 0.001 kg/cm3. If a fish grabs the bait, ...
March 24, 2010

ENVIRONMENTAL SCIENCE
A viewpoint expressed in the video material emphasizes the idea that every type of species has its meaning and purpose, and is important part of biodiversity. Unique characteristics of different species contain the secret of harmony in the world, benefiting from each other by ...
January 19, 2010

Algebra/story problem
Can someone help me work this problem please? The equation y= -1777x+27,153 can be used to predict the number of gun deaths in the United States x years after 2000, that is x=0 corresponds to 2000, x=2 corresponds to 2002, x=4 corresponds to 2004, and so on. Predict the number...
January 7, 2010

Marketing
What arguments can you make against the common assumption that marketers only worry about advertising?
December 1, 2009

General Physics
A 0.40 - kg object connected to light spring with a force constant of 19.6 N/m oscillates on a frictionless horizontal surface. If the spring is released from rest, determine the maximum speed of the object.
November 12, 2009

math
when y=-sinx and y=sin2x - sinx are added together and graphed, why do the maximum values of two sin functions occur where they do?
October 13, 2009

Chopsticks
3x^2-8x+1=0
August 31, 2009

literary
I am writing my father's obituary - he passed away unexpectedly on Monday. He was from a very small town and always quoted verse that ended with "And when I go (return) home, I am a boy again" Walt Whitman. Dylan Thomas. Please. Please. I have a deadline tomorrow...
June 24, 2009

algebra
Graph the equation using the slope and the y- intercept y= 8/5x+5
June 7, 2009

7th pre-algebra
I need help understanding how to slove two step equations. Example -10 - k=-36
May 11, 2009

math
This is incorrect
April 9, 2009

art -year8-writeacher
thankyou for finding those websites for me they are a great help. i looked at those myself but i wasn`t sure if they were right. thanks again!
April 3, 2009

art -year8
i need to design a renaissance outfit for art. please could someone help me find some websites that show some outfits that can help me. thankyou.
April 3, 2009

Orientalism
What are the three aspects of Orientalism
March 25, 2009

Reiny! Reiny! Reiny!
1. Oanh walked from her home to the grocery store at 3 mi/h and jogged home at 6 mi/h. Her total round trip was 15 minutes (1/4h). How far from Oanh's home is the grocery store? (use an equation to solve this) Help, I am totally clueless on this.
February 5, 2009

Rewrite each polynomial as the product of two binomials. 1. y^2 + 6y + 9 2. 25x^2 - 10x + 1 3. 36 - y^2 I don't understand how to do these problems, especially what the direction is telling me to do. Someone help me please?
January 16, 2009

Algerba 1
Rewrite each polynomial as the product of two binomials. 1. y^2 + 6y + 9 2. 25x^2 - 10x + 1 3. 36 - y^2 I don't understand how to do these problems, especially what the direction is telling me to do. Someone help me please?
January 16, 2009

Chemistry
Thank you for helping me with this.
December 16, 2008

Chemistry
We did a flame testing lab today with the following metal ions: Sodium, Na^+1 Barium, Ba ^2+ Calcium, Ca ^2+ Copper, Cu ^2+ Potassium, K ^+1 Strontium, Sr ^2+ Lithium, Li ^+1 The question asks to explain the effect of the nitrate ion solution on the color emission. Please help...
December 16, 2008

algebra
yes. thank you very much
December 1, 2008

algebra
how would you go about solving this problem? a x 2b/6 x 4/5a
December 1, 2008

algebra
so would i do this: 82.1 - 86 = -3.9 now that i have the -3.9 would that be the final answer to the question "what is the deviation from the mean that day?"
November 9, 2008

algebra
so would i do this: 82.1 - 86 = -3.9 now that i have the -3.9 would that be the final answer to the question "what is the deviation from the mean that day?"
November 9, 2008

algebra
How would i go about answereing this question? The mean temperature in new york one summer was 86 degrees. if the temperature on july 22 of that summer was 82.1 degrees, what was the deviation from the mean that day?
November 9, 2008

math
How would i go about answereing this question? The mean temperature in new york one summer was 86 degrees. if the temperature on july 22 of that summer was 82.1 degrees, what was the deviation from the mean that day?
November 9, 2008

Writing
thanks, do you have any ideas that interest you that would be about 3,000 words
November 8, 2008

Writing
thank you very much. my main interest was the white house. do you have any topics with why question that i could do for that??
November 8, 2008

Writing
i have to do a research paper for journalism class. It has to be something that has to do with washington, d.c. but the topic cant be too generalo. it has to be something specific that i will be able to write 1,500 to 3,00 words. Also, the topic has to answer a "WHY"...
November 8, 2008

physics
A pendulum consists of an object of mass 1.07 kg that hangs at the end of a massless bar, a distance 1.14 m from the pivot point. Calculate the magnitude of the torque due to gravity about the pivot point if the bar makes an angle of 22° with the vertical.
October 9, 2008

physics
A 4422.0 kg truck is parked on a 10.8° slope. What is the friction force on the truck?
October 9, 2008

physics
A woman has a mass of 64.2 kg. What is her weight on earth?
October 9, 2008

Algebra
Solve sytems of equations for 7x-3y=31 and y-5=3x I need to find what x and y equal. thanks!
April 20, 2008

Algebra
Explicitly explain how to tell an answer is correct when solvingi systems of equations. -thanks so much!
April 3, 2008

math
find distance from (-4,2) to (5,14)
March 23, 2008

Physical Science
If you poked 3 holes in a vertical line in a bottle filled with water, which hole will spurt water the furthest? Why? -thanks so much for your help!
March 17, 2008

finance and accounting
Account Word Problems like this I seem not to get the concept , please give me an exam as how to figure out this problem. 1. The liabilities of Acosta Corporation equal one-third of the total assets. And stockholders equity is \$160,000. What is the amount of the liabilities. ...
March 4, 2008

finance and accounting
Account Word Problems like this I seem not to get the concept , please give me an exam as how to figure out this problem. 1. The liabilities of Acosta Corporation equal one-third of the total assets. And stockholders equity is \$160,000. What is the amount of the liabilities. ...
March 3, 2008

Science
How does the ozone effect the wind patterns
January 22, 2008

US history
Hi! i am wondering if you can explain amendmant 7 in more depth. Thanks!
January 19, 2008

Algebra
What is the differance between a discrete graph and a continuous graph? Thanks so much!
January 16, 2008

Pre
A) List two examples of pairs of numbers that share a common factor. B) List a variable pair with a common factor. C) Why do u think ab+ac is called "simplified form"? I don't really what they are asking me to do... ummmm, anyone help me?
January 7, 2008

Just Wondering
Whats Christmas anyways? Like, how did it become a true holiday? What is the story behind it?
December 24, 2007

Math
You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and algebraic equation that shows...
December 10, 2007

Pre-Algebra
You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and algebraic equation that shows...
December 10, 2007

Pre-Algebra
You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and algebraic equation that shows...
December 10, 2007

French
so, how do u really say this quote in french? "You are in love when suddenly reality is in your dreams, and you cannot sleep anymore." help?
December 4, 2007

Pre-Algebra
What does P-E-M-D-A-S mean? I know they are the orders of operation, but I forgot what each letter stand for??? HELP!
November 28, 2007

Pre-Algebra
Thank you!
November 28, 2007

Pre-Algebra
okay so the decimal is 0.001 and I need to convert it to a fraction and a precent? how do I do that??
November 28, 2007

OMG! thank you sooo much! genius! it works by the way!!!
November 26, 2007

X- 0 1 2 3 4 5 6 Y- -7 -4 -1 2 5 8 11 this is a x and y table I need to find out wat the rule is to get y. So the equation would start out like: Y=?????? wat do u need to do with x to get y? and I need help badly! so please!
November 26, 2007

algebra
(p+3)(p-4)(p-3)(p+4)
November 25, 2007

algebra
consider three consecutive even intergers, the least of which is x. Write a polnomial representing the product of these three intergers.(p+3)(p-4)(p-3)(p+4)
November 25, 2007

math
1/4 think money like 25 cents
November 12, 2007

Social Studies
Name 3 documents and or important people involving the government? For example: as one of the documents, The Articles of Confederation can be one. Can anyone name 2 more at least??? PLZ!
November 12, 2007

Pre-Algebra
So since 2/3 of Spinner 1 is sedans (The 3rd is a truck), and 1/2 of Spinner 2 is purple (the other half is a green), write a multipilcation problem to describe the probability of spinning a purple sedan. Write a problem to describe the probability of spinning a purple truck. ...
November 8, 2007

Pre-Algebra
So since 2/3 of Spinner 1 is sedans (The 3rd is a truck), and 1/2 of Spinner 2 is purple (the other half is a green), write a multipilcation problem to describe the probability of spinning a purple sedan. Write a problem to describe the probability of spinning a purple truck. ...
November 8, 2007

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