Sunday
October 4, 2015

Posts by anna

Total # Posts: 2,211

Physics
A skier speeds down a smooth ski slope which is at an angle of θ = 21° with the horizontal. The mass of the skier is 75 kg. Take the downhill direction to be positive and uphill to be negative. What is the net force acting on the skier? Ok, so I have set up these ...
September 28, 2015

2nd Law Physics
You fashion a sling shot with a rather long and wide rubber band and practice hurling pebbles. You pull back on the center of the band with a force of 2.31 N. The angle between the two halves is 107°. What is the tension in the band? I get the gist of setting up Newton'...
September 28, 2015

Math
Gisela has 135 cds 11 are pop music she has 3 times as many rocks cds as she had classical how many rocks cds does she have?
September 27, 2015

chemistry (Physchem)
Calculate the standard heat of reaction at 250C (298K) and 1 atm pressure of 3FeO(s) + 2Al(s) → Al2O3(s) + 3Fe(s) in terms of per mole of Al2O3 formed, per mole of Fe formed, per mole of FeO reacted, per mole of Al reacted and per g of Fe formed. ΔH298K,FeO(s) = -63...
September 27, 2015

Physics
A mover has to move a heavy sofa of mass 146 kg to the second floor of the house. He uses a rope to pull the sofa up a ramp from the first to the second floor. As he pulls the sofa he makes sure that the rope is parallel to the surface of the ramp which is at 30.0° to the ...
September 27, 2015

math
What is the commission on a sale total of \$300,000 if you keep 8%? help!
September 23, 2015

Math
The fence in David's backyard is 14 feet 5 inches long how many total inches is that
September 20, 2015

Chemistry college
You are given a recipe for a buffer that contains 5% (w/v) MgSO4.7H2O. However, you only have MgSO4 anhydrous available to you. How much MgSO4 anhydrous do you need to make 0.5L of the buffer with the same molar concentration as in the recipe? Show your calculations
September 16, 2015

physics
A 10.0 microCoulomb point charge is fixed in place at the origin. A 2.00-microCoulomb point charge is released from rest at x = 0.500 m. Because of the repulsive force between the two point charges, the 2.00-microCoulomb charge is accelerated in the +x direction. What is the ...
September 15, 2015

chemistry
Hi! Can you please check if my answers are correct? And, can you please tell me any other details you think are important to add. Also, the last two questions i have no clue how to answer. can you help? thanks so much! 3.A burning candle produces a luminous flame. What is the ...
September 11, 2015

chem
If you have a properly adjusted hot flame, which is pale blue with three distinct cones, what is observed if the gas control valve is slightly closed? Explain.
September 11, 2015

Math
by 3 pm the temperature had increased by another 5 degrees. was the temperature at 3pm positive or negative
September 9, 2015

Chemistry
I'm having trouble turning mM to mOsmoles. The equation goes like this: red blood cell are placed into a beaker filled with .5L of a 150mM NACL solution. NACL is non-penetrating solute and will not cross the red blood cell membrane. I have 150mM/0.5L * 2mOsM/100mM But ...
September 8, 2015

Physics
A constant force of friction of 50 N is acting on a body of mass 200kg moving initially with a speed of 15m/s. How long does the body take to stop? What distance will it cover before coming to rest?
July 30, 2015

Geometry
A square football field 3 mi. wide.
July 29, 2015

Solving Geometry Formulas
If the perimeter of a rectangle is 48 ft. and the width is 9 ft., what is the length of the rectangle?
July 29, 2015

Solving Geometry Formulas
The perimeter of a rectangle is 56 meters. If the width of the rectangle is 7 meters, find the length.
July 28, 2015

Intro to Algebra- Geometry
2 cans will be needed.
July 28, 2015

Intro to Algebra- Geometry
A sail on a sailboat has a base of 10 ft. and a height of 18 ft. and needs to be sealed with water repellent. One can of water repellent will cover 50 sq. ft., how many cans will be needed to cover the sail?
July 28, 2015

Intro to Algebra
Sally is making a tablecloth and wants to put lace around the edges. How much lace will she need to purchase if the radius is 1.5 ft.
July 28, 2015

Probability and statistics
The hydrocarbon emissions at idling speed in parts of million (ppm) for automobiles of 1980 and 1990 model years are given for 20 randomly selected cars. 1980 models: 141 359 247 940 882 494 306 210 105 880 200 223 188 940 241 190 300 435 241 380. 1990 models: 140 160 20 20 ...
July 20, 2015

english teachers?
are there any english teachers on here at this time?
July 17, 2015

Biology
I have any idea for these.
July 15, 2015

Biology
1) Microscopic hairs of the windpipe are always __________. 2) The cilia of the windpipe move harmful substances __________. 3) You build a heavy gust of air when you __________ or __________. 4) Coughing and sneezing help push harmful substances from the __________.
July 15, 2015

Biology
1 hair 2 mucus 3 mucus
July 15, 2015

English
I am writing a 300 word short story(or a "'personal' narrative essay") for the prompt: lessons we learn affect one's future. So far I have a general idea: I want the lesson to be loyalty and truth and I want the effect to be that the character would learn...
June 21, 2015

Physics
So we did this lab about how we are to measure the half life of the beta decay of indium 116 (the indium 116 is captured by indium 115 and undergoes beta decay to become tin 116. Since the Indium 116 I reused I understand that every time we use it, the indium 116 becomes a ...
June 17, 2015

Physics
The Golden Gate Bridge in San Francisco has a main span of length 1.28 km, one of the longest in the world. Imagine that a steel wire with this length and a cross-sectional area of 4.00 x 10-6 m^2 is laid on the bridge deck with its ends attached to the towers of the bridge, ...
June 15, 2015

Physics
What is the significance in the observation of discrete spectral lines in the emission spectrum of hydrogen??
June 15, 2015

Physics
A converging lens has a virtual object located a finite distance away. Which of the following must be true? (Select all that apply.) a) f > q b) The image is virtual. c) p < 0 d) The image is real. e) p > 0 Hi, can someone explain which is correct or incorrect? Thank ...
June 10, 2015

English
I am just about the processes of writing a short story and I am looking for a word/phrase that can properly describe a departure, without a destination(I am not going to specify anything to reflect the tone and theme of my story) that is just taken based on whim and for self ...
June 9, 2015

Physics
A pair of speakers separated by distance d = 0.900 m are driven by the same oscillator at a frequency of 670 Hz. An observer originally positioned at one of the speakers begins to walk along a line perpendicular to the line joining the speakers as in the figure below. (a) How ...
June 8, 2015

Physics
A pair of speakers separated by distance d = 0.900 m are driven by the same oscillator at a frequency of 670 Hz. An observer originally positioned at one of the speakers begins to walk along a line perpendicular to the line joining the speakers as in the figure below. (a) How ...
June 8, 2015

Physics
I did a lab about Standing waves on a string and it asked me the following qeuestions: Discuss any errors arising from the method used to establish the standing wave pattern. - I think air resistance, linear density of string is non uniform, tension of the string is not ...
June 5, 2015

Physics
Suppose you have a string that is being made to vibrate at a specific frequency, f. The speed of waves on the string is v. The length of the string that is vibrating, L, is adjustable. When the length of the string has been adjusted so that the fundamental standing wave ...
June 4, 2015

Physics
thank you!
June 4, 2015

Physics
A stretched string is attached to an oscillator. On which of the following quantities does the wavelength of the waves on the string depend? Select all that apply. The choices are: A) The frequency of the oscillator. B) The tension applied to the string. C) The amplitude of ...
June 4, 2015

Math
Wait! Nevermind, figured it out! Use linear equation right?
June 3, 2015

Math
Which of the following equations gives the relationship between S and T in the table below? S 1 2 3 4 5 6 T 1 4 7 10 13 16 How do you find equations again?
June 3, 2015

Math
1. Cate went on a trip of 120 miles at x miles per hour. Returned over same route at 5miles/hour faster than previous rate.If time for return trip was one-third of an hour less than time for the outgoing trip,how do you find x? (Set up the chart right, and used the time column...
June 3, 2015

Math
June 2, 2015

Math
I brought a book and paid \$1.80 in sales tax. If the tax was 8%, what was the cost of the book. How do I solve this problem?
May 25, 2015

Language Arts
Each day, Wyatt created both humorous and touching poetry in his attic room. his attic room both humorous and touching poetry Each day in his attic room
May 23, 2015

english
Please place all of the chairs in the middle of the room.
May 11, 2015

Spanish
Thank you so much Sra. You are always so kind to help.
May 2, 2015

Spanish
Sra. does this essay look ok? It is comparing the Hispanic views on death and the US view. Cultura hispana celebra la muerte de muchas maneras, mientras que la cultura americana creo que es demasiado triste para la vida diaria. La vida para los hispanos es difícil. La ...
May 2, 2015

Computer Architecture!!
How can we find the value in decimal stored in the AC register, after executing the MARIE program
April 24, 2015

college algebra
a chemist needs to prepare 28 ounces of a 8% hydrochloric acid solution. find the amount of 14% solution and the amount of 7% solution he should mix to get this solution.
April 20, 2015

math word problem
You are in a car. The car begins your journey by traveling 3 miles south in a straight path. The car then travels 9 miles east in a straight path and then turns and travels another 9 miles south in a straight path to end the journey. What is the straight-line distance between ...
April 16, 2015

SOUTH CAROLINA STATE HISTORY
9. Which event did NOT change the culture of the United States during the early 1920s? (1 point) a. bank failures that closed factories and decreased job opportunities b. installment plans used to purchase expensive consumer goods c. boll weevil infestations which changed ...
April 15, 2015

Economic
Suppose that Betsy’s utility function is given by the equation U=Y0.3 where Y is measured in thousands of dollars. Betsy’s current job pays her \$20,000 per year and she can earn this amount next year with certainty. Betsy is offered a different job but in this new ...
April 15, 2015

Physics
You have 250 g of water in an aluminium calorimeter with a mass of 125 g. How long will it take to increase the temperature of the water and calorimeter from 20C to 37C if the system is heated by a resistive heating element with 8 V across the resistor and 0.75 A flowing ...
April 12, 2015

English
What are each of these are like: 1. Control 2. Conformity 3. Equality 4. Individualism
April 12, 2015

Trigonometry (identities) (last help needed)
I apologize; it is simplifying. The homework is for my identities unit, though. And number 1 does not have a typo. Sorry!
April 9, 2015

Trigonometry (identities) (last help needed)
1. (2cosx-2secx)(3cosx^2+3secx^2+β) 2. (16tanxsecx-4secx)/(8tanxsecx+4secx) 3.sinxcosx^3+cosx^4 (hint: GCF) 4. (cosβ+sinβ)^2
April 9, 2015

Trigonometry (identities)
I tried these but for 4 I seemed to get a reasonable answer: cos^2(β)-cot^2(β) How does that look? Please correct me if I'm wrong - it felt too simple.
April 9, 2015

Trigonometry (identities)
1. (-8cosxsinx+4cos2x)^2 +(4cosx^2+8sinxcosx)^2 2. cos(α-β)cosβ-sin(α-β)sinβ 3. 1+(sinx-cosx)(sinx+cosx) 4. (cosβ-cotβ)(cosβ+cotβ)
April 9, 2015

Physics
A parachutist drops out of a plane at an altitude of 150m and accidentally drops his camera. If the parachute opens the instant he drops out of the plane and he descents at a constant speed of 6 m/s, how much time separates the arrival of the camera on the ground from the ...
April 5, 2015

Trigonometry (identities)
Simplify: 1. sin(α+β)+sin(α-β) 2. (-8cosxsinx+4cos2x)^2 + (4cos^2x+8sinxcosx)^2 3. sqrt(sin^4xcosx) * sqrt(cos^3x)
March 31, 2015

chemistry
Answer is 40.1L. After conversions, plug it all into V=nRT/P
March 31, 2015

chemistry
Try PV=nRT, where R=0.08206, P=pressure, V=volume, n=moles, and T=temperature. Convert temperature to Kelvin, Torr to atm (pressure), and g to moles (divide by molar mass).
March 31, 2015

Chemistry
This sounds right to me! Next step to find kJ per gram, would be to convert your J to kJ, and divide by the amount of grams given. This is odd, however, since normally these problems want kJ per mole, not gram. I hope this helps!
March 31, 2015

chemistry
Keep in mind: n=moles, so divide your grams by molar mass to get moles. Then, as said above, plug everything in. V=nRT/P
March 30, 2015

Chemistry
Set up: convert units --> PV=nRT --> PV/RT=n --> moles to molecules. (0.993atm*2.00L)/(0.08206*296.15K)=0.08176 mol N2 0.08176 mol*(6.022x10^23 molecules/1 mol)=4.92x10^22 molecules N2 Let me know if this helps!
March 30, 2015

English
B. It's for sure.
March 27, 2015

math
The area of a circle is given by the formula A = ðr2, where r is the radius. If increasing the radius of a circle by 1 inch gives the resulting circle an area of 100ð square inches, what is the radius of the original circle?
March 26, 2015

History
ohhhhh its C xD
March 24, 2015

History
so A :)
March 24, 2015

History
South Carolina .
March 24, 2015

History
Why did the popularity of the Grange decline? a.)Its leaders were weak and ineffective. b.) It became corrupt and lost the farmers' trust.**** c.) It did not address the farmers economic needs. d.) it was not able to obtain political power in the state
March 24, 2015

History
thank you mrs.sue and reed :) if i have anymore questions do you mind helping ? if not its ok i understand :)
March 24, 2015

History
so for the last one would it be A ?
March 24, 2015

History
wait would number 2 be b ? i was confused on that one . and be for the last question also ?
March 24, 2015

History
im confused about that last one would it be a or b ? and yes for number 1 and im not sure for number 2 because thats the whole question
March 24, 2015

History
please help i have my answers just not sure if im correct :( what criticism did tillman direct at conservations? a.)they controlled the office of the govnr b.)they didnt think blacks should vote ****** c.)they believed in white supremacy d.)they didnt care about the common ...
March 24, 2015

Spanish
Hola Sra. Do these look ok? Part I Complete el párrafo por llenar los espacios en blanco con la forma correcta de los verbos entre paréntesis. ¡OJO ! No todos requieren el subjuntivo. Hoy martes estoy en el aeropuerto y tengo que pasar la aduana. El aduana ...
March 20, 2015

Pre-Algebra
Equation M: y = 3x + 4 Equation P: y = 3x + 7 Which of the following options is true about the solution to the given set of equations? No solution One solution Two solutions Ininite solutions I thought it was infinite solutions but i got the answer wrong.
March 20, 2015

chemistry
How much energy is needed to completely remove an electron from n = 2 in a hydrogen atom?
March 18, 2015

Spanish
Thank you so much for your tips. Hopefully these are better. 1. La fiesta se considera excesa pero todo el mundo participa. 2. Se abrazan, celebran y bromean acerca de la muerte. 3. Ella era una buena madre y estaba triste que su hijo era un ladrón. 4. Él pens&...
March 12, 2015

Spanish
Hola Sra.! Do these look ok? Escriba un párrafo (por lo menos 5 oraciones) para contestar cada una de las preguntas siguientes. 1. Identifique dos temas principales de “The Day of the Dead” por Octavio Paz. El ensayo es sobre la cultura de la fiesta y de la ...
March 12, 2015

math
Sinx/Cscx -1+sinx/Cscx +1= 2tan^2x
March 8, 2015

Chemistry
i converted from pKa to Ka for all three values. i don't know where to go from there.
March 5, 2015

Chemistry
Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.250 M phosphoric acid solution. [H3PO4] = ? [H2PO4^-] =? [HPO4^2-]=? [PO4^3-]=? [H^+]=? [OH^-]=? pH=?
March 5, 2015

chemistry
A container of gas at 24 psi is compressed to one eighth its original volume. What is the new pressure of the gas? Answer in units of psi.
March 5, 2015

chemistry
A chemist prepares a sample of hydrogen bromide and ﬁnds that it occupies 249 mL at 60◦C and 552 Torr. What volume would it occupy at 0◦C at the same pressure? Answer in units of mL
March 5, 2015

Precalc+trig
Solve tan(40/90) for the double angle cos(2theta). I know I use the x^2 + y^2 = r^2 formula and cos(2theta) = cos^2theta - sin^2theta. But I don't understand my answer
March 4, 2015

calculus
Find Indefinite Integral of dx/(x(x^4+1)). I think that Im complicating it too much. I moved the dx out making it 1/(x(x^4+1))dx than 1/(x^5+x)dx. I think i have to use formula indef integral of dx/(x^2+a^2) = 1/a(tan^-1(x/a)) but im stuck i dont know what to do next. I would ...
March 3, 2015

chemistry
Given the following balanced chemical equation, if 15.4 g AgNO3 are reacted, how many moles of AgCl are produced? 2 AgNO3 + BaCl2 → 2 AgCl + Ba(NO3)2
March 1, 2015

chemistry
A sample of oxygen that occupies 2.5 × 10−6 mL at 508 mm Hg is subjected to a pressure of 1.2 atm. What will the ﬁnal volume of the sample be if the temperature is held constant? Answer in units of mL
February 25, 2015

physics
Ohh I see the pulling force is 220.5 The frictional force is 66 For the normal force I actually got 367.85 I just don't understand how you solved for acceleration by saying 1/2-1/5*7.96
February 22, 2015

physics
Sorry I meant 47 kg.
February 22, 2015

physics
For the frictional force I got 61.4 For the magnitude of the Normal force I got -398.5 and for the amount of force pulling you down the slope I got -250.2 I don't think that's right though.
February 22, 2015

physics
Oh sorry. To find the frictional force is it (0.18)*(47.0)(9.80)cos37 degrees and the magnitude of the Normal force is (47.0)(9.80)cos37 degrees
February 22, 2015

physics
Is this right? (45.0)*(9.80)*(sin35 degrees)= a number a number - frictional force = answer
February 22, 2015

physics
You are skiing and have a mass of 47 kg and are on a slope making an angle of 37 degrees above horizontal. The coefficient of kinetic friction between the skis and the snow is 0.18. What is the amount of force pulling you down the slope? What is your acceleration down the slope?
February 22, 2015

statistics
I also need help with this question!!!!
February 22, 2015

Spanish
Thank you Sra. Yes I got the question and answers backwards in part II. SCAMP really helps. I will add that to my notes. Thank you.
February 20, 2015

Spanish
Hola Sra. Are these correct? Part I Indique si las palabras dadas son sinónimos, antónimos o que no son relacionadas. 1. maletas y equipaje sinónimos 2. despegar y aterrizar antónimos 3. abrochar y confirmar no son relacionadas 4. ida y vuelta sin&...
February 20, 2015

Math Help
Hi! Can someone please help me with these? Thanks! :) Directions: Look for the direction angle for vector v. If necessary, round your answer to the nearest tenth of a degree. 1.) v = 8i - 10j 2.) w = -4i - 3j
February 18, 2015

Math
u = <7, -3> and v = <-2, 4>. Find u + 3v.
February 18, 2015

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