Questions Asked in December 2006

Most Popular Questions of December 2006

  1. physics

    THree blocks of masses 3m, 2m and m are connected to strings A,B, and C. The blocks are pulled along a rough surface by a force of magnitude F exerted by string C. The coefficient of friction between each block and the surface is the same. Which string

  2. finding c: calc

    let f(x)=square root x. if the rate of change of at x=c is twice its rate of change at x=1, then c=? what???? i don't get get it. to begin with, i took the derivative if that helps which is 1/(2*sqrtx) . f'(x) = 1/(2*sqrtx) is correct f'(x=1) = 1/2 The

  3. physics.

    A car travels forward with constant velocity. It goes over a small stone, which gets stuck in the groove of a tire. The initial acceleration of the stone, as it leaves the surface of the road is, a)vertically up b)horizontally forward c)horizontally

  4. AP chem

    I have a problem set due tomorrow, and two problems in it were not covered in class. The first is this: Molybdenum has an atomic radius of 0.145 nm. The volume of its cubic unit cell is 0.0375 nm^3. What is the geometry of the molybdenum unit cell? I have

  5. ap chemistry

    Discuss briefly the relationship between the dipole moment of a molecule and the polar character of the bonds within it. WIth this as a basis, account for the difference between the dipole moments of CH2F2 and CF4. does anyone have any idea? the greater

  6. physics

    A student is testing the kinematic equations for uniformly accelerated motion by measuring the time it takes for light-weight plastic balls to fall to the floor from a height of 3 m in the lab. The student predicts the time to fall using g as 9.8 m/s^2 but

  7. Physic (concepts-please check my thoughts)

    A net torque applied to a rigid object always tends to produce? a)translational acceleration b) rotational equilibrium c) rotational acceleration d) rotational inertia e) none of these work (c) Torque produces torsion and tends to produce rotation. The net

  8. Chemistry

    In a lab, we added NH3(aq) to CuSO4(aq), and the solution turned dark blue with a precipitate. The problem is that the products ( Cu(NH3)4 and SO4) should be soluble, no? The question is then, what is the percipitate? The ppt is Cu(OH)2. The dark blue

  9. Economics

    An industry currently has 100 firms, all of which have fixed costs of $16 and avg. variable cost as follows: Q Avg. Variable Cost ($) 1 1 2 2 3 3 4 4 5 5 6 6 a. Compute marginal cost and avg. total cost. b. the price is $10. what is the total quantity

  10. MATH -BRAIN TEASER- PLEASE HELP

    page # D-76 What Relation Is a Doorstep to a Doormat? Both are stepped on. no You didn't put any parameters on this and I think its a great answer. How bout the relation being a stepson (steps on) I got astearther.... No wait it's A Step Farther eh....??

  11. Last physics help question (my thoughts given)

    A 160-N child sits on a light swing and is pulled back and held with a horizontal force of 100N. The tension force of each of the two supporting ropes is: a) 60N b) 94N c) 120N d) 190N e) 260N work: weight is down, the pull is back, so the tension must act

  12. phyiscs

    How do I do these? Draw a free-body diagram for each of the following objects? a. a projectile in motion in the presence of air resistance b. a rocket leaving the launch pad with its engines operating c. a heavy crate being pushed across a rough surface a.

  13. science

    is paper towel a conductor or insulator? How good does it conduct or insulate. insulator. Dry paper is a good insulator.

  14. physics (please check work)

    A uniform rod AB is 1.2 m long and weighs 16N. It is suspended by strings AC and BD. A block P weighing 96N is attached at E, 0.30N from A. The tension force in the string BD has a magnitude. My work: Taking torque around AC string

  15. calc help showed work

    If the function f has a continuous derivative on [0,c], the the integral(o to c) of f'(x)dx= a)f(c)-f(0) b)absolute value (f(c)- f(0)) c) f(c) d)f'(x)=c e)f"(c)-f"(0) My work: so the the answer to the integral is f(x) and when find the answer from o t0 c,

  16. english

    "Injustice anywhere is a threat to justice everywhere" what does this mean? Someone explain it plz. I think it means that if there is no justice or no fairness in a certain place, makes others think that doing the same thing is okay. thanx.

  17. SCIENCE

    Please see if I have the right answer. The three atoms in a water molecule are held together by oxygen bonds, covalent bond, surface tension, hydrogen bonds, or gravity. I think it's covalent bonds. Am I right? Water molecules, even inflowing water, can

  18. physics

    When there is no air resistance objects with different masses fall with....... A. equal accelerations and different displacements B. equal accelerations and similar displacements C. different accelerations and similar displacements D. different

  19. Physics questions ( I posted all my work)

    A uniform rod AB is 1.2 m long and weighs 16N. It is suspended by strings AC and BD. A block P weighing 96N is attached at E, 0.30N from A. The tension force in the string BD has a magnitude. My work: Taking torque around AC string

  20. d/dx

    d/dx( ln |sin(pi/x)| ) = ? Thanks. If those are absolute value signs, the derivative will not exist when sin (pi/x) = 0, because of the sign change that occurs there. Assume sin (pi/x) > 0 Let u(x) = pi/x and v(x) = sin x, and use the chain rule. d/dx ln

  21. PHYSICS

    1. Vecor A is 3 units in length and points along the positive x-axis. Vector B is 4 units in length and points along a direction 150 degrees from the positive x-axis. What is the direction of the resultant relative to the positive x-axis? a. 80 degrees b.

  22. Chemistry

    Compounds like CCL2F2 are known as chloroflourocarbons, or CFCs. These compounds were once widely used as refrigerants but are now being replaced by compounds that are believed to be less harmful to the environment. The heat of vaporization of CCl2F2 is

  23. The lord of the flies-English

    Why is percival unable to remember his name and address? Please help!! :( He is one of the "littleuns". He is so traumatized by the events he lives through that he forgets what civilization is about, including his name.

  24. ap chem

    A mole of helium gas contains 6.02x10^23 helium atoms. How many helium atoms are there in a micromole of helium? How many moles of helium does 1.25x10^20 atoms of helium represent? ~I have no idea how to start or what the value of a micromole is?

  25. physics

    what kind of force field surrounds a stationary electric charge? What additional field surrounds it when it moves? "what kind of force field surrounds a stationary electric charge?" Electric field. "What additional field surrounds it when it moves?"

  26. Statistics

    Find the probability of correctly answering the first 2 questions on a multiple choice test if random guesses re made and each question has 6 possible answers. My answer is 1/36 Assume that the data has a normal distribution and the number of observations

  27. Chemical Formulas and Reactions

    When aqueous copper(II)chloride reacts with aqueous ammonium phosphate, soluble ammonium chloride forms and copper(II) phosphate precipitates out of solution. 1. Write the balanced molecular equationfor this reaction. 2. Write the balanced complete ionic

  28. calc

    the volume of a cylindrical tin can with a top and a bottom is to be 16*pi cubic inces. if a minimum amont of tin is to be used to construct the can, what must be the height, in inches, of the can? volume of cyliner is pi*r^2*h do i like take derivitive of

  29. physics (work posted)

    For a body to be in equilibrium under the combined action of several forces. a) all the forces must be applied at the same point b) all of the forces form pairs of equal and opposite forces c) the sum of the components of all the forces in any direction

  30. Spanish

    What does this mean? "¡Viva el espanol!" I looked up on an online translator and is said "Spanish lives". Is that correct though? Is that what it would really mean in spanish? Thanks for your help! it means long live spanish THanks! Be careful with using

  31. Math

    I need help with my math homework.I searched for homework help forums and I found the Jiskha Website on the Google Website so this is my first time.I am new. Math Homework: What is the value of number 3 in 2,539? What is the value of number 9 in 4,879 What

  32. Chem

    Fungal laccase is .390% Cu by mass. If a fungal laccase molecule contains 4 Cu atoms, what is the molar mass of fungal laccase? Molar mass= mass of 4Cuatoms/.390

  33. Physics

    An object is dropped from rest from the top of a 400 m cliff on Earth. If air resistance is negligible, what is the distance the object travels during the first 6s of its fall? a)30m b)60m c)120m d)180m e)360m I got a) as my answer. I used x-x_i = v_i * t

  34. physics

    An object is thrown with velocity v from the edge of a cliff above level ground. Neglect air resistance. In order for the object to travel a maximum horizontal distance from the cliff before hitting the ground, the throw should be at an angle theta with

  35. chemistry

    0.872g sample containing only NaBr and KBr gives 1.052g AgBr. what's the % of each salt? This is the type of problem that cannot be answered without other information. I think you have made a typo in your problem I worked through it and I get negative

  36. frogs

    Two girls caught 25 frogs. Lisa caught four times as many as Jen did. How many frogs did Jen catch? Lisa => 4x Jen => x 4x + x = 25 x = 5 Lisa => 20 Jen => 5 jen caught 5 frogs

  37. physics

    A block of mass 3 kg initially at rest is pulled along a friction less horizontal surface with a force of 4N. The speed of the block at t=2s is a)4/3 m/s b)8/3m/s c)4 m/s d)8m/s e)24m/s For this problem this is a graph. Some of the points on the graph are

  38. Probaility

    The rates of on time flights for commercial jets are continuously tracked by the US Department of Transportation. Recently, Southwest Air had the best rate of 80% of its flight time on time. A test is conducted by randomly selecting 15 southwest flights

  39. some science

    a filter tip or a cigarette acts as both a filter and a condenser. which of the following cannot be removed, assuming the filter tip is 100% efficient? a. carbon monoxide, boiling point -191 degrees. b. nicotine, boiling point 247 degrees. c. tar, boiling

  40. physics concepts (please check over my work)

    A uniform cyclinder made of lead has the same mass and the same length as a uniform solid cylinder made of wood. The rotatonal inertia of the lead cylinder compared to the wooden one is: I thought at first that the rotational inertia cannot be known or

  41. Environmental Science

    only 10 percent of the energy is passed from one trophic level to the next. Explain where the other 90 percent of the available energy goes. Thank you for using the Jiskha Homework Help Forum BUT we are here to HELP you not to DO the work for you. It is

  42. chemistry

    Can someone help me with this? 1)What new element is formed if magnesium-24 is bombarded with a neutron and then ejects a proton? Write a balanced nuclear equestion for this transmutation. Is this beta decay? That's what I'm thinking, but I'm not sure. It

  43. physiology

    The single most important factor influencing potassium ion secretion is a) the potassium ion content in the renal tubule cells b) intracellular sodium levels c) potassium ion concentration in blood plasma d) pH of the ICF c

  44. organic chemistry!

    Just wanted to know if I have named the following compounds correctly..and wanted to know if there are any short-hand or easier methods of naming organic compounds because they are a bit confusing!I tried drawing structural formulas for the following as

  45. Forces w/ tension

    Assume that three blocks portrayed below move on a frictionless surface and that a 42 N force acts on the 3.0 kg block. Determine (a) the acecleration given the system, (b) the tension inthe cord connecting the 3.0kg and the 1.0 kg blocks, and (c) the

  46. algebra

    solve the compound inequality 3x-5>-17 and 4x+3

  47. Microeconomics

    Larry, Moe, and Jo run the only saloon in town. Larry wants to sell as many drinks as possible without losing money. Jo wants the saloon to bring in as much revenue as possible. Moe wamts to make the largest possible profits. Using a single diagram of the

  48. Another Problem...PLz Help COunt Iblis

    Statements Reasons 1. 3x - 7 = -4 2. 3x - 7 + 7 = -4 + 7 3. 3x + 0 = -4 + 7 4. 3x + 0 = 3 5. 3x = 3 6. (1/3) 3x = 3 (1/3) 7. (1/3) 3x = 1 8. 1x = 1 9. x = 1 Is this problem about explaining each step? yeah like you have to write the property of each Are

  49. Chemistry

    Can you please answer this question: Both water and carbon dioxide are triatomic molecules. Explain why one of these molecules is polar and the other is nonpolar? Carbon dioxide is linear :C::O::C: and therefore has no net electrical dipole. Water is a

  50. Economics

    you are hired as the consultant to a monopolistically competitive firm. The firm reports the following information about its price, marginal cost, and average total cost. Can the firm possibly be maximizing profit? If the firm is profit maximizing, is the

  51. ETH

    1400 WORD AUTOBIOGRAPHICAL RESEARCH PAPER THAT ANALYZES THE INFLUENCES OF RACE AS IT RELATES TO YOUR COMMUNITY. HOW HUMAN INTERATION IN YOUR COMMINTY HAVE BEEN RACIALIZED. FOR THE COMMINITY YOU CAN CONSIDER RELATIONS WITHIN YOUR NEIGHBORHOOD, LOCAL

  52. Cash Budgeting Question

    Cash Budgeting – Helen Bowers, owner of Helen’s Fashion Designs, is planning to request a line of credit from her bank. She has estimated the following sales forecasts for the firm for parts of 2006 and 2007: May 2006 $180,000 June

  53. Chem 12

    How can I do this: 3KNO3(aq)+ Fe(SCN)3(aq) + NaOH(aq) ? what do you have to do? write the products it makes. I don't know the products it makes. I have to figure out what adding all those produces. Im not sure its even possible? yes it is possible. first

  54. MATH -BRAIN TEASER- PLEASE HELP

    Page # D-74 How Would You Describe a Dead Skunk? A skunked skunk. no What kind of answers do you have for the ones you have correct? exstankt extinct

  55. literature

    When did the book To Kill a Mockingbird take place? Harper Lee wasn't specific about the dates, but apparently it took place in the mid 1930s. Check this background out. http://www.sparknotes.com/lit/mocking/context.html Yes, that's what I thought.

  56. Finance

    Please answer following: 1. The purpose of secondary trading is to provide liquidity and competition between investments. provide a market for securities not handled in primary trading. provide jobs for brokers and dealers. provide lower commissions than

  57. Economics

    You’ve been hired by an unprofitable firm to determine whether it should shut down its unprofitable operation. The firm currently uses 70 workers to produce 300 units of output per day. The daily wage (per worker) is $100, and the price of the firm’s

  58. islamic studyes

    is it bad to fight? why? Most religions believe it is bad to fight -- except when you're defending yourself -- or fighting bad impulses within yourself.

  59. Math

    8 runners are entered in the 1000-meter run. How many different first, second, and third place finishes could possibly occur? Is the answer 24? No. 8x7x6 = 336 The first place can be any of eight. For each first place possibility, there are seven possible

  60. Economics

    Among monopoly, oligopoly, Monopolistic competition, and perfect competition, how would you classify the markets for each of the following drinks? a. tap water b. bottled water c. cola d. beer I think it would be... a. Monopoly b. Oliopoly c. monopolistic

  61. Subject Verb agreement.

    Which of the following sentences does illustrate subject verb agreement? I think it's this one, but I'm not sure. Tricia, as well as all her colleagues, are being trained on new equiptment. The subject and verb in that sentence agree. Good job. Each

  62. math,algebra

    can someone correct this for me: Translate the following statements into inequalities. Let x represent the number in each case. 2 times a number, increased by 28, is less than or equal to 6 times that number. My answer: 2x+28

  63. Critical Thinking

    What is the meaning of validity, truth, and soundness as they relate to the area of logical syllogisms http://www.memoriapress.com/articles/logic.html scroll to Truth, Validity and Soundness What is the meaning of validity, truth and soundness as they

  64. Physics

    A sled weighing 60 N is pulled horizontally across snow so that the coefficient of kinetic friction between the sled and the snow is 0.100. A penguin weighing 70 N rides on the sled. If the coefficient of static friction between the penguin and the sled is

  65. Economics

    6. Show the effect of each of the following events on the market for labor in the computer manufacturing industry. Use graphs. a. Congress buys personal computers for all American college students. Wouldn't the demand curve shift to the right while the

  66. The children of willesden lane

    1.How does Lisa Jura's music shape her identity? 2.How important is Lisa's religion to her identity? 3.What changes does Lisa and her family experience so far in the book? Which do you think were te most difficult for Lisa to accept? for her parents? how

  67. physics

    An object weighting 300 N is suspended by means of two cords. (There is a cord on the ceiling with is at 45 degrees. The second cord is attached to the wall and is horizontal. These two cords are attached to a cord which has the 300N object on it.) The

  68. Physics

    A 50.0 kg parachutist jumps out of an airplane at a height of 1.00 km. The parachute opens, and the jumper lands on the ground with a speed of 5.00 m/s. By what amount was the jumper's mechanical energy reduced due to air resistance during this jump? so,

  69. physics

    Identical forces act for the same length of time on two different masses. The change in momentum of the smaller mass is A) smaller than the change in momentum of the larger mass, but not zero. B) larger than the change in momentum of the larger mass. C)

  70. Physics

    A stationary arrangement of two crayon boxes and three cords. Box A has a mass of 11.0kg and is on a ramp at angle è=30.0 degrees; box B has a mass of 7.00 kg and hangs on a cord. The cord connected to Box A is parallel to the ramp which is frictionless

  71. Physical Education

    I just want to know what different branched there are in taking a major in physical education. I know you can go into teaching, athletic training, but I want to know if there are any other areas. Physical tharapy, Sports Medicine, Phisiology of astronauts

  72. Math

    I have a question: How would you solve this? a dozen dozen apples at half a dozen dimes a dozen? In this cause is dozen 12? And half a dozen dimes in 60 cents? would that be 120? b/c a dozen dozen is 24 so u have 24 apples and then you have 60 cents per

  73. FRENCH! HELP!

    so i have this french test tomorrow on imparitive, and subjonctif. i have had a lot of trouble remembering them, and telling them apart. can anyone help!? that would be fantastic! thank you so much! its urgent! Imperative (note spelling) means giving a

  74. Economics

    50. In both monopolistic competition and non-price-discriminating monopoly, isn't the marginal revenue curve lies below the demand curve? 51. A monopolistically competitive firm is producing an output level where marginal revenue is greater than marginal

  75. Microbio

    Can someone check my answer please? How does the antibiotic penicillin kill bacterial cells? Is it more effective against gram positive or gram negative organisms? Explain. Most bacteria produce a cell wall that is composed partly of a macromolecule called

  76. Algebra

    What is the sum of 38 and twice a number is 124. Find the number 43 The sum of 38 and twice a number is 124. Find the number.

  77. physics (please check work)

    Four identical particles, each with mass m, are arranged in the x,y plane like a cross. They are connected by light sticks to form a rigid body. If m=2.0kg and a=1.0 m the rotational inertia of this array about the y axis is: work: I know that I= mr^2

  78. Science help plz

    Since all matter is made up of atoms that have positive and negative charges, how can an object be neutral? Explain. thanks Well, if the number of postive equals the number of negative, we define that as neutral. They spread evenly in matter, so no net

  79. Physics

    Three identical balls, with masses M, 2M, and 3M are fastened to a massless rod of length L as shown. The rotational inertia about the left end of the rod is: That's the layout below. Would calculus be needed in this problem (intergration) because then Im

  80. Probability

    Roll two fair dice. what is the probability that you get a 2 and a 5 without regard to which is on which die? What is the probability of at least one 2 or one 5? What is the probability of a sum of 7? "what is the probability that you get a 2 and a 5

  81. math

    concrete can be purchased cubic yard. How much will it cost to pour a slab 17 feet by 17 feet by 2 inches for a patio if the concrete costs $40.00 per cubic yard? Change 2" to feet, find volume of patio in cubic feet, change to cubic yards, and multiply by

  82. Business Calculus

    A manufacturer has found that marginal cost is dc/dx=3x^2-60x+400 dollars per unit when x units have been produced. The total cost of producing the first 2 units is $900. What is the total cost of producing the first 5 units? I would integrate, you are

  83. Analytical Proof

    The Theorum of Apollonius states in triangle ABC, if M is the midpoint of BC, then AB^2 + AC^2 = 2AM^2 + 2MC^2. Prove this theorum using analytic methods.

  84. Environmental Science

    Explain how the nitrogen used for making proteins in a lion's body traveled from the atmosphere to the lion. How will it be returned to the atmosphere after the lion dies? Google Nitrogen cycle animal

  85. physics rework (please help)

    A 160-N child sits on a light swing and is pulled back and held with a horizontal force of 100N. The tension force of each of the two supporting ropes is: A uniform plank is supported by two equal 120N forces at X and Y at both ends of the plank.The

  86. rate of change

    A missile rises vertically from a point on the ground 75,000 feet from a radar station. If the missile is rising at the rate of 16,500 feet per minute at the instant when it is 38,000 feet high, what is the rate of change(in radians per minute) of the

  87. Economics

    3. Suppose the Clean Springs Water Company has a monopoly on bottled water sales in California. If the price of tap water increases, what is the change in Clean Springs' profit-maximizing level of output, price, and profit? Explain in words and with a

  88. Math

    HELLO, THIS IS MY FIRST TIME USEING THE JISKHA WEBSITE. I NEED HELP WITH MY HOMEWORK. PLEASE HELP ME WITH MY HOMEWORK! THANK YOU! _______________________________________ MY MATH HOMEWORK: 30 DIVIDED BY 10 56 DIVIDED BY 6 55 DIVIDED BY 10 30/10=3 55/10=5.5

  89. Physics

    A ball is launched with a velocity of 10 m/s at an angle of 50.0 degrees to the horizontal. The launch point is at the base of a ramp of horizontal length 6.00 m and 3.60 m high. A plateau is located at the top of the ramp. a) Does the ball land on the

  90. Urgent-Chemistry Help

    I need help with the heat effects and calorimetry worksheet. Please explain how to solve it! Thank you so much! A metal sample weighing 45.2g and at a temperature of 100.0 C was placed in 38.6g of water in a calorimeter at 25.6 C. At equilibrium the

  91. math , algebra

    Can someone correct these (1) -5^2-3 25-3 22 (2) The sum of m and n, divided by the difference of m and n. My answer: (m+n)/ (m-n) (3) The quotient when 3 more than a number is divided by 3 less than that same number My answer: (x+3)/(x-3) These are all

  92. chemistry

    Use the following information to identify element A and compound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it has been filled with nitrogen gas at a pressure of 790. torr and a

  93. Art

    whats the definition of proportion http://www.answers.com/proportion See definitions 1, 2, and 4 especially. Then scroll down to see additional information from different dictionaries and thesauri. =)

  94. physics

    A novice pilot sets a plane's controls, thinking the plane will fly at 2.50 * 2 to the 2nd power km/h to the north. if the wind blows at 75km/h toward the southeast, what will the plane's new resultant velocity be? use graphical techniques. Are you sure

  95. TO ALL STUDENTS

    Please remember these things: 1. This is a homework help website; please put your subject (math, science, English, or ??) in the subject line to make it faster for each teacher to find those questions in his/her areas. An even better subject heading would

  96. physics

    The nucleus of a hydrogen atom is a single proton, which has a radius of about 1.0 10-15 m. The single electron in a hydrogen atom normally orbits the nucleus at a distance of 5.3 10-11 m. What is the ratio of the density of the hydrogen nucleus to the

  97. solving for x math

    2e^(4x^2)=3 how do i solve for x. do i use the ln methode because i don't know how to do that. by calculator, i got x=.168 but i don't know how to show my work. please help me solve for x. Take natural logs of both sides. ln 2 + 4 x^2 = ln 3 4 x^2 = ln

  98. Chloral Hydrate

    What is the molar mass of chloral hydrate and how many moles of C2H3Cl3O2 molecules are in 500 g chloral hydrate. Also, what is the mass in grams of 2.0 x 10^-2 mol chloral hydrate? Molar mass? You can add them up. Starting at the left, 2 carbons, three H,

  99. physics

    It is known that the possible values for the magnetic quantum number m range between -9 and +9. Determine the orbital quantum number and the smallest possible value of the principle quantum number. l = n =

  100. ENGLISH

    Hello, what is the format of "affiliation" in a lab report? A lab report? Are you sure this isn't a science assignment?? http://www.google.com/search?hl=en&q=affiliation+lab+report&btnG=Google+Search ??