Most popular questions and responses by Sara
  1. math

    Find dy/dx and d2y/dx2. x = et, y = te−t

    asked on July 28, 2014
  2. Chemistry

    Restart the PhET simulation and set it up in the following manner: select Oscillate, select No End, and use the parameters in parentheses by sliding the bars for Amplitude (1.00 cm), Frequency (1.20 Hz ), Damping (none), and tension (highest). Using the

    asked on October 18, 2018
  3. statistics

    the probability that a house in an urban area will develop a leak is 5%. if 23 houses are randomly selected, what is the probability that none of the houses will develop a leak?

    asked on April 28, 2013
  4. chemistry

    Using your answer from Part A, calculate the volume of a mole of Na atoms (in cm3/mol ). Assume that the entire volume is occupied by Na atoms leaving no gaps or holes between adjacent atoms. (Answer A is V= 2.70*10^7)

    asked on November 10, 2008

    Which of the problems in the construction of the CPI might be illustrated by each of the following situations? Explain. a. the invention of the Sony Walkman b. the introduction of air bags in cars c. increased personal computer purchases in response to a

    asked on April 12, 2009
  6. Percentage

    A flat-screen TV costs $1,400. The TV is on sale for 35% off. What's the discount price?

    asked on January 4, 2017
  7. Chemistry

    Given the thermodynamic data in the table below, calculate the equilibrium constant for the reaction: 2SO2(g)+O2--> 2SO3 Substance (DeltaH^o) (Delat S^o) SO2 -297 249 O2 0 205 SO3 -395 256 Answer (it was given) 2.32x10^24 Even though the answer is given

    asked on March 16, 2008
  8. Check my answers

    Question 1.Choose the answer that identifies the case of the parentheses word. My grandparents always go to the square dances with the Warrens and (them). nominative objective possessive *** my answer none of the above Question 2. Choose the pronoun that

    asked on October 15, 2014
  9. business math

    Jen purchased a condo in Naples Florida for $699,000. She put 20% down and financed the rest at 5% for 35years. What are Jens total finance charge?

    asked on April 12, 2015
  10. AP Chemistry

    A 5.0 M solution of HNO3 is titrated with 0.3 M NaOH. Identify the species that have the highest concenttrations in the solution being titrated halfway to the equivalence point. A 25.15 ml of 0.35 m HNO3 was titrated with an unknown concentration of NaOH.

    asked on March 29, 2015
  11. Math

    One of the sides of a parallelogram is 4.2 cm and the altitude to that side is 3.6 cm. Find the perimeter of the parallelogram if the altitude to the other side is 2.4 cm.

    asked on February 23, 2017
  12. Math

    Sarah secured a bank loan of $200,000 for the purchase of a house. The mortgage is to be amortized through monthly payments for a term of 15 yr, with interest rate of 6%/year compounded monthly on the unpaid balance. She plans to sell her house in 5 yr.

    asked on May 15, 2012
  13. Maths

    50 divided into two parts such that if 6 is subtracted from one part , 12 is added to the second part we get same number .

    asked on December 2, 2016
  14. English

    Story : The Ethanol Debate Natalie Stewart What feature of the selection BEST illustrates that it is a persuasive essay? A) < -- A? the chart showing the rise in corn prices B) the information on how farmers feed their herds C) the description of how

    asked on May 11, 2015
  15. chemistry

    When the conductivity is at a minimum, what must be true about the amount of Ba(OH)2 compared to H2SO4? The Ba(OH)2 dissociates as Ba+2 + 2 OH-. H2SO4 dissociates as 2 H+ + SO4-2. Why does it not conduct at this low point? Why does it conduct more before

    asked on July 25, 2012
  16. physics

    Three identical thin rods, each of length L and mass m, are welded perpendicular to one another as shown below. The assembly is rotated about an axis that passes through the end of one rod and is parallel to another. Determine the moment of inertia of this

    asked on November 6, 2008
  17. chemistry

    Calculate the mass of oxygen gas required to occupy a volume of 6 L at a pressure of 20.9 kPa and a temperature of 37◦C.

    asked on April 30, 2015
  18. business math

    Andres Michael bought a new boat. He took out a loan for $23,980 at 3.75% interest for 4 years. He made a $4,470 partial payment at 4 months and another partial payment of $3,180 at 9 months. How much is due at maturity?

    asked on October 10, 2014
  19. anatomy

    if you wanted to flex your arm, and both your biceps and triceps contracted simultaneously, what would happen? and where is most of the muscle weight found in humans?

    asked on October 28, 2007
  20. Chemistry (please help me!)

    H2(g) + CO2(g) H20(g) + CO(g) When H2(g) is mixed with CO2(g) at 2,000K, equilibrium is achieved according to the equation above. In one experiment, the following equilibrium concentrations were measured: [H2]=0.20 M [CO2]=0.30 M [H2O]=[CO]=0.55M a) What

    asked on February 25, 2007
  21. Biology (please help!!)

    Explain the process that takes place in the stroma including and reactants going in nd the products produced from these processes in a. bright sunlight and in b. darkness. c. what happens over an extended period of darkness of many days? What I need to

    asked on November 21, 2016
  22. Physics

    Multiple Concept Example 9 provides background pertinent to this problem. The magnitudes of the four displacement vectors shown in the drawing are A = 16.0 m, B = 12.0 m, C = 13.0 m, and D = 23.0 m. Determine the (a) magnitude and (b) direction for the

    asked on May 29, 2012
  23. math

    write each addiction vertically. decide which new groups you will make. then add to see if you were correct. 256+1.273 A new ten? A new hundred? A new thousand?

    asked on October 1, 2013
  24. math help

    Round to nearest ten thousandth: 4.803621

    asked on January 22, 2014
  25. chemistry 30a

    What volume (in mL) of an 8% w/v acetic acid solution would be needed to form 2.2 L of carbon dioxide gas at 25.2 degrees Celsius and 0.9982 atm? Assume the acid is reacted with excess sodium bicarbonate, and round your final answer to two sig figs.

    asked on March 12, 2012
  26. Mendelian Genetics

    Assume you are performing a cross between a plant that is heterozygous for the dominant traits red flowers and wrinkled seeds, with a plant that is homozygous for the recessive traits white flowers and smooth seeds. Assume the alleles are R for red

    asked on January 20, 2015
  27. English

    The speaker in “I, Too, Sing America” survives adversity because he feels faith that he will one day be affirmed by white America. he has uncovered the hypocrisy around him. he is better than the people who are oppressing him. hope that he can one day

    asked on February 6, 2012
  28. calculus

    A street light is mounted at the top of a 6-meter-tall pole. A man 2 m tall walks away from the pole with a speed of 1.4 m/s along a straight path. How fast is the tip of his shadow moving when he is 16 m from the pole?

    asked on October 16, 2012
  29. chemistry

    Based upon the intermolecular forces present, rank the following substances according to the expected boiling point for the substance: MgF2, H2O, HCl, N2

    asked on April 3, 2014
  30. Chemstry

    I just copied this because i have a couple more questions on this part.... Sulfuric acid/ Lead Battery: -the electrodes for the battery are composed of Pb(s), PbO2, and/or PbSO4. What are the half reaction occuring at each electrode? include electrolysis

    asked on April 28, 2008
  31. Math

    When a class took a math test, 15% of the class failed, 25% made some mistakes (but didn’t fail), and 24 students got perfect scores. How many students were in the class?

    asked on February 23, 2017
  32. Chemistry

    Using household bleach and saltwater of the same molarity, describe the quantities of each that would me needed to make 30 ml of a solution that contained 50% of the hypochlorite in household bleach.

    asked on February 22, 2015
  33. English-Writeacher

    Recently my class and I read a short story called "A l is Calm." It is basically about this girl named Katherine and her grandma who is suffering from the Alzheimer's disease. It starts out as this: Katherine's grandma has to be taken to the doctor because

    asked on October 5, 2010
  34. math

    The value of Sara's new car decreases at a rate of 8% each year. 1.Write an exponential function to model the decrease in the car's value each month. 2.Write an exponential function to model the decrease in the car's value each week. 3.Write an exponential

    asked on November 17, 2017
  35. Linear algebra

    Let L1 be the line passing through the point P1=(−1, −1, 8) with direction vector →d1=[1, 0, −3], and let L2 be the line passing through the point P2=(7, −11, 14) with direction vector →d2=[1, 2, −3]. Find the shortest distance d between

    asked on March 18, 2017
  36. Chemistry

    About 13% of the acid in a 0.10M solution of a weak acid dissociates to form ions. What is the H3O+ concentration? What is the OH- concentration? What is the pH of the solution?

    asked on July 18, 2012
  37. Chemistry

    Calculate the molarity and the molality of an NH3 solution made up of 30 g of NH3 in 70 g of water. The density of the solution is 0.982 g/ml. Molar Mass of NH3 = 17.04 g

    asked on December 2, 2010
  38. Physics

    Three astronauts, propelled by jet backpacks, push and guide a 118 kg asteroid toward a processing dock, exerting the forces shown in the figure, with F1 = 32 N, F2 = 56 N, F3 = 38 N, θ1 = 30°, and θ3 = 60°. What is the (a) magnitude and (b) angle

    asked on March 31, 2016
  39. English-Friendship Poem

    What are Friends For-by rosellen brown What are friends for, my mother asks. A duty undone, visit missed, casserole unbaked for sick Jane. Someone has just made her bitter. Nothing. They are for nothing, friends, I think. All they do in the end-they touch

    asked on April 7, 2010
  40. Algebra

    What is the solution to 5-t=23? My answer is 18. What is the value of b if -7+b=-8? My answer is -1. What is the solution to 5q=-75? My answer is either -25 or -15. What is the solution to -6z=72? My answer is -12. What is the solution to -7+h=12? My

    asked on September 15, 2015
  41. History

    what are two themes that would be appropriate for thematic time lines of important events from prehistory to A.D.1600.

    asked on January 18, 2015
  42. precalculus

    an airplane flying at 550 miles per hour has a bearing of N 52(DEGREES)E. After flying 1.5 hours, how far north and how far east has the plane traveled from its point of departure?

    asked on March 11, 2010
  43. AP Human Geography

    1. What role does migration play in the geographic pattern? 2. How about interaction & isolation after migration takes place? 3. When do dialects begin to become so different that they may be viewed as a different language? 4. How has the Internet

    asked on November 18, 2015
  44. physics

    A 48-kg girl stands on a 8-kg wagon holding two 19.5-kg weights. She throws the weights horizontally off the back of the wagon at a speed of 9.0 m/s relative to herself. Assuming that the wagon was at rest initially, what is the speed with which the girl

    asked on December 5, 2015
  45. math

    Two cars are side by side. One is 3.9 meters long. The other is 6% shorter. How long is the second car? I know the answer is 3.7, but how?

    asked on June 25, 2018
  46. Science-Enr. Phys.

    A box of books weighing 325 N moves at a constant velocity across the floor when the box is pushed with a force of 425 N exerted downward at an angle of 35.2 degrees below the horizontal. Fink Mu,k between the box and the floor. There have been several of

    asked on February 25, 2007
  47. Chemistry

    Prepare M/20 oxalic acid solution.Using this solution, find molarity, strength, and percentage purity of the sodium hydroxide solution.

    asked on June 13, 2016
  48. Science

    What are neap tides, and why do they occur? Neap tides are the weaker tides. They occur when the sun and the moon are perpendicular to each other with respect to earth. Please correct me if I'm wrong, thanks

    asked on February 10, 2010
  49. finance

    Jiminy's Cricket Farm issued a 30-year, 7.2 percent semiannual bond 9 years ago. The bond currently sells for 85.5 percent of its face value. The book value of this debt issue is $107 million. In addition, the company has a second debt issue, a zero coupon

    asked on May 9, 2016
  50. MATH

    You wish to mentally estimate the total cost of items that have the following prices: $1.85, $.98, $3.49, $9.78, and $6.18. Rounding off the items to the nearest half-dollar, your estimate of the total cost of these items is A. $22.50. B. $22.30. C.

    asked on August 18, 2012
  51. physics

    A ball of mass 0.075 kg is fired horizontally into a ballistic pendulum. The pendulum mass is 0.350 kg. The ball is caught in the pendulum, and the centerof mass of the system rises a vertical distance of 0.145 m in the earth's gravitational field. What

    asked on March 28, 2010
  52. English

    In the following sentence, identify the part of speech of the italicized word. Thousands of years ago, fish were caught in nets and traps. A. Verb B. Preposition C. Pronoun D. Conjunction Is it B?

    asked on August 16, 2012
  53. Maths

    divide 1000 among a,b,c in such a way that a gets 120 more than b and b gets rs 110 more than c .hw much each get

    asked on December 4, 2016
  54. Equilibrium concentrations, please help!!!

    Lead metal is added to 0.150 M Cr3+(aq). Pb(s)+2Cr3+(aq)⇌Pb2+(aq)+2Cr2+(aq). KC=3.2×10−10 What is [Pb2+] when equilibrium is established in the reaction? What is [Cr2+] when equilibrium is established in the reaction? What is [Cr3+] when equilibrium

    asked on February 17, 2017
  55. physics

    If 335 g of water at 65.5 °C loses 9750 J of heat, what is the final temperature of the water? Liquid water has a specific heat of 4.18 J/(g.°C). °C (Answer a number only, no units. Round to the tenth place). This is an example of an endothermic or

    asked on May 22, 2017
  56. English-Poetry

    My Guilt When I was a child I walked two miles to school accompanied by a neighbor boy two years younger. Freddie was fat and freckle faced with wheat-straw hair and a mean stepmother. It was late fall and one day his father bought him a new winter cap. It

    asked on April 21, 2010
  57. Physics

    Suppose your car was mired deeply in the mud and you wanted to use the method illustrated in the figure to pull it out. (a) What force in newtons would you have to exert perpendicular to the center of a rope to produce a force of 10,000 N on the car if the

    asked on November 7, 2016
  58. chemistry

    In the reaction between CV+ and –OH, one species is acting as the Lewis base, the other as the Lewis acid. (Note: A Lewis acid is not necessarily a proton donor. It is, however, always an electron pair acceptor). Which reagent is the Lewis acid? A. CV+

    asked on July 13, 2010
  59. math

    Use Green's Theorem to evaluate the line integral along the given positively oriented curve. integral of xy2 dx + 4x2y dy C is the triangle with vertices (0, 0), (2, 2), and (2, 4)

    asked on November 11, 2014
  60. Physics - Mechanics and Ocsillatory Motion

    The force shown in the figure acts on a 1.7-kg object whose initial speed is 0.44 m/s and initial position is x = 0.27 m. the figure can be found at: [[webassign dot net forwardslash walker forwardslash 07-16 dot gif]] (a) Find the speed of the object when

    asked on October 30, 2010
  61. Algebra

    can somebody please help me with this question I've spent more than 3 hours on this, still nothing Let L1 be the line passing through the point P1=(2, −4, −6) with direction vector →d1=[1, 0, 2]T, and let L2 be the line passing through the point

    asked on March 18, 2017
  62. econ

    The terms below are measures or individual components of the money supply. Specifically considering the money supply of the United States, rank these items from largest to smallest in terms of dollar value. Currency, M2,M1,Balances in savings accounts,

    asked on March 27, 2014
  63. chemistry

    a student dissolves 80 mg of a crude product in 4.5 mL( the minimum required) of methanol at 25 deg C . She cools the solution in an ice bath and obtains crystals. The crystals are recovered by filtration and rinsed with 0.5 mL of ice-cold methanol. After

    asked on February 11, 2013
  64. chemistry

    suppose you heat a hydrate too quickly and some of it was lost as it spattered out of the container. Explain how this would affect the calculated percent of mass and the chmical formula

    asked on November 18, 2009
  65. chemistry

    Aqueous sodium sulfate reacts with aqueous barium chloride to produce solid barium sulfate and aqueous sodium chloride. the solution contains 3.44g of barium chloride. you have a 0.282M solution of sodium sulfate. determine the volume of the sodium sulfate

    asked on April 17, 2016
  66. Physics

    A light ray of wavelength 610 nm is incident at an angle θ on the top surface of a block of polystyrene surrounded by water. Find the maximum value of θ for which the refracted ray will undergo total internal re- flection at the left vertical face of

    asked on January 25, 2011
  67. Chemistry

    Dinitrogen pentoxide, N2O5, decomposes by first-order kinetics with a rate constant of 0.15 s-1 at 353 K. (a) What is the half-life (in seconds) for the decomposition of N2O5 at 353 K? (b) If [N2O5]0 = 0.0579 mol·L-1, what will be the concentration of

    asked on June 28, 2013
  68. AP Chemistry

    A buffered solution was created by mixing solutions of NH4Cl and NH3 at 25 C. Which species, NH4+ or NH3, has the highest concentration in this buffered solution?. Justify your answer.

    asked on March 26, 2015
  69. Calculus

    A right circular cylinder is changing shape. The radius is decreasing at the rate of 2 inches/second while its height is increasing at the rate of 5 inches/second. When the radius is 4 inches and the height is 6 inches, how fast is the a) volume changing

    asked on November 2, 2014
  70. science

    A car of mass 2900 kg collides with a truck of mass 4800 kg, and just after the collision the car and truck slide along, stuck together. The car's velocity just before the collision was < 34, 0, 0 > m/s, and the truck's velocity just before the collision

    asked on June 25, 2014
  71. math

    The formula of a trapezoid is A=1/2h(b1+b2) Express b1 in terms of A,h,and b2 I did A=1/2hb1+1/2hb2 A=hb1/2 +hb2/2 A-hb2(2/h)=hb1/2(2/h) A-b2=b1 I am not sure if this is correct? I was confused on how to do this. Any help or explanation is greatly

    asked on October 4, 2016
  72. physics

    A string is wrapped around a uniform disk of mass M = 1.6 kg and radius R = 0.10 m. (Recall that the moment of inertia of a uniform disk is (1/2)MR2.) Attached to the disk are four low-mass rods of radius b = 0.17 m, each with a small mass m = 0.6 kg at

    asked on July 31, 2014
  73. Chemistry

    Just having some trouble with this chemistry problem.. Thanks for help! Toxic carbon monoxide (CO) gas is produced when fossil fuels such as petroleum burn without enough oxygen. The CO can eventually be converted to CO2 in the atmosphere. Automobile

    asked on January 15, 2013
  74. Calculus

    Calculate the height of a cylinder of maximum volume that can be cut from a cone of height 20 cm and base radius 80 cm , please help me

    asked on December 25, 2011
  75. Sixth Grade Simplest Form

    Im having a hard time trying to solve this problem. Can someone please help me? Marcial found a recipe for fruit salad that he wanted to try to make for his birthday party. He decided to triple the recipe. 3 1/2 cups thinly sliced rhubarb 15 seedless

    asked on September 16, 2014
  76. HELP! 5th grade math

    Trying to help my child in 5th grade. Shannon pours 4 different liquid ingredients into a bowl The sum of the liquid ingredients is 8.53 liters. Two of her measurements are in milliliters and two of her measurements are in liters. Give an example of

    asked on April 13, 2014
  77. Chemistry

    The solubility of CO2 in water at 25 degrees C and 1 atm is 0.034 mol/L. What is its solubility under atmospheric conditions? (The partial pressure of CO2 in air is 0.0003 atm.) Assume that CO2 obeys Henry's law. My Answer: 1.02 x 10^-5 mol/L

    asked on December 2, 2010
  78. biology

    A bacterium has a genome size of 6.0 X 106 base pairs. There is one Origin of Replication (ORI) and each DNA polymerase catalyzes the addition of 1,000 nucleotides/second. How much time is needed to replicate the entire genome?

    asked on February 20, 2017
  79. English

    Why don’t the narrator and the other man want to hold Edward for ransom? Is their motivation internal or external? in " Why, You Reckon?"

    asked on February 4, 2012
  80. History

    Which was not a motivation for European exploration in the fifteenth and sixteenth centuries? the Muslim invasion of Spain the desire to find a sea route to Asia-} my answer the promise of riches intellectual curiosity

    asked on February 23, 2015
  81. Square Roots

    Between what two consecutive integers does the square root of 124 lie? 11 and 12 12 and 13 13 and 14 14 and 15

    asked on November 11, 2014
  82. History

    What do you think about what I wrote? Please give me feedback! And what grade would you give it? (This homework question was removed due to a copyright claim submitted by K12 Inc.) My answer: The biggest art movement that came out of World War One was the

    asked on January 14, 2011
  83. Math

    The area of a parallelogram with a side of 5.6 in is equal to the area of a rectangle with sides 7 in and 8 in. Find the altitude to the given side in the parallelogram.

    asked on February 23, 2017
  84. Chemistry

    How to I find the spectator ions of BaCl2+K2SO4->2KCl+BaSO4

    asked on November 9, 2015
  85. Grammar

    1. Choose the answer that identifies the form of the verb in the sentence. Cindy is painting her room purple. present present participle past past participle Question 2. Choose the answer that identifies the tense of the verb in the sentence. Has the rain

    asked on September 23, 2014
  86. Chemistry

    Which of the following is a bond in which a metal transfers one or more electrons to a nonmetal? ionic bond hydrogen bond metallic bond covalent bond

    asked on December 1, 2015
  87. Chemistry

    Balance TeO3^3- + N2O4 --> Te +NO3^- using oxidation numbers

    asked on June 15, 2015

    Which indicator is best suited to determine the equivalence point of a titration of diethlyamine with HBr? pKb of diethylamine=3.16 A) phenolpthalein pKHIN ~9 B) bromo blue pKHIN ~4 C) alizarin yellow pKHIN~11 D) methyl violet pKHIN~ 1 E) phenol red pKHIN

    asked on January 29, 2011
  89. social studies

    how did the spanish conquest affect native americans and africans?

    asked on March 31, 2008
  90. How many milliliters of a stock solution of 6.00 M

    How many milliliters of a stock solution of 6.00 M HNO3 would you have to use to prepare 0.190 L of 0.490 M HNO3? I used the equation M1V1=M2V2 6M*V1 = 0.190L*0.490 M lead me to this V1=0.190L*0.490M/6.00 M =0.0931 L per M/6.00M =0.0155166L

    asked on August 28, 2015
  91. World History

    I need help. In a brief essay, explain three ways in which the Roman Catholic Church responded to the spread of Protestantism in the sixteenth century. Describe each part of the church’s response using specific facts.

    asked on April 6, 2015
  92. Science

    Why do gas giants have more moons than the terrestrial planets? The gas giants have more moons than the terrestrial planets because of their great masses which result in stronger gravitational fields. Any other info would be appreciated, please tell me if

    asked on February 16, 2010
  93. physics

    a roller coaster moves 85m horizonally, then travels 45m at an angle of 30 degrees above the horizontal. what is its displacement from its starting point?

    asked on October 29, 2008
  94. science

    A hoop of mass M = 4 kg and radius R = 0.4 m rolls without slipping down a hill, as shown in the figure. The lack of slipping means that when the center of mass of the hoop has speed v, the tangential speed of the hoop relative to the center of mass is

    asked on July 21, 2014
  95. Chemistry

    Diethyl ether has a boiling point of 34.5C, and 1-butanol has a boiling point of 117C. Both of these compounds have the same numbers and types of atoms. Explain the difference in their boiling points. The answer I found was that: only 1-butanol can form

    asked on December 6, 2010
  96. chem

    Which of the following elements would you expect to gain electrons in chemical changes? (Select all that apply.) gold chromium zirconium nitrogen iodine

    asked on September 21, 2010
  97. chemistry

    How much ice (in grams) would have to melt to lower the temperature of 350 of water from 24 to 4? (Assume the density of water is 1.0 .)

    asked on August 27, 2010
  98. Science

    9. Which one of the following statements is characteristic of liquid water? A. It has a definite shape but not a definite volume. B. It has neither a definite shape nor a definite volume. C. It has a definite volume and a definite shape. D. It has a

    asked on August 21, 2012
  99. Algebra( check my answers)

    1. Juan deposited $200 in a savings account earning 3% interest over 2 years. What was the total amount of interest earned after 2 years? $12 $24 $120 ( my answer) $240 2. Mary borrowed $11,000 at 5% interest for 4 years. What was the total interest? $22

    asked on September 19, 2014
  100. Science

    Which of the following statements is true about Earth's magnetic poles? A.They are located at earths geographic poles B.They are the areas where Earths magnetic field is weakest. C. They are the areas where Earths magneic field is strongest. D. Earth has

    asked on April 27, 2016


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