Questions Asked in April 2007

Most Popular Questions of April 2007

  1. Physics

    One end of a uniform meter stick is placed against a vertical wall. The other end is held by a lightweight cord that makes an angle, theta, with the stick. The coefficient of static friction between the end of the meter stick and the wall is 0.390. A. what

    asked by Karla on April 3, 2007

    WHAT ARE SOME ADVANTAGES FOR BOTH REVIWER AND WRITER-OF PEER REVIEWS? HOW WOULD YOU ENCOURAGE A RELUCTANT Idella, when you type in all-caps, two things happen: ~~it's harder

    asked by IDELLA JONES on April 13, 2007
  3. Physics

    A cylinder is fitted with a piston, beneath which is a spring, as in the drawing. The cylinder is open at the top. Friction is absent. The spring constant of the spring is 4100 N/m. The piston has a negligible mass and a radius of 0.023 m. (a) When air

    asked by Mary on April 24, 2007
  4. Calculus

    I really need help with this problem an automobile accelerates from rest at 1 + 3(square root)t mph/sec for 9 seconds. How far does it travel in those nine seconds? I have found that the velocity, after nine seconds, is 63 I have figuredout the answer but

    asked by James on April 1, 2007
  5. physics

    Three point charges, q1, q2, and q3, lie along the x-axis at x=0, x=3 cm, and x=5 cm, respectively. Calculate the magnitude and direction of the electric force on each of the three points when q1=+6.0 muC, q2=+1.5 muC, and q3=-2.0 muC. I would add the

    asked by Mischa on April 11, 2007

    Ok I don't understand how to find similar figures when using proportions. Can someone explain it to me? Two figures that have the same shape are said to be similar. When two figures are similar, the ratios of the lengths of their corresponding sides are

    asked by Ashley on April 24, 2007
  7. calculus

    a particle moves along the curve xy=10. if x=2 and dy/dt=3, what is the value of dx/dt. i'm guessing this is something to do with parametric equations. if x is 2, then y=5. but how do i get dx/dt. you have to differentiate the equation with respect to t so

    asked by Anonymous on April 21, 2007
  8. Economics

    Suppose that the residents of Vegopia spend all of their income on cauliflower, broccoli, and carrots. In 2006 they buy 100 heads of cauliflower for $200, 50 bunches of broccoli for $75, and 500 carrots for $50. In 2007, they buy 75 heads of cauliflower

    asked by Sarah on April 2, 2007
  9. chemistry

    Why if you dissolve cobalt chloride solution in distilled water and then pour acetone in it, the bottom part of the graduated cylinder is red and the top part is blue? What do you mean by it has one color with water of crystallization? CoCl2*6H2O is a

    asked by Lydia on April 11, 2007
  10. Math (Statistics)

    How do I go about tackling this problem? The American Medical Association wishes to determine the percentage of obstetricians who are considering leaving the profession becaose of the rapidly increasing number of lawsuits against obstetricians. How large a

    asked by Edward on April 29, 2007
  11. Sales tax

    tom paid 695.5 for a tv when 7% sales tax was included in that price what was the price of the tv before the tax and how much sales tax did tom pay? You can set it up this way: 1.07x = 695.5 x = _______ That will tell you the price of the TV. The

    asked by Arkuk on April 13, 2007
  12. sum geometric series

    what is the sum of geometric infinite series 3/2+ 9/16+ 27/128+ 81/1024=.... i know the formula is S=a/(1-r) my teacher, he usually transforms into a formula of the sum series and finds out a and r.but i don't how to do that. the pattern i saw is 3/2 +

    asked by david on April 9, 2007
  13. Chemistry

    Phthalic acid, H2C8H404, is a diprotic acid used in the synthesis of phenolphthalein indicator. Ka1= 1.2x 10^-3, and Ka2 = 3.9 x 10^-6. a) Calculate the hydronium-ion concentration of a .015 M solution. b) What is the concentration of the C8H4O4^-2 ion in

    asked by Rachael on April 2, 2007
  14. balanced equation

    ? MnO4– + ?H+ + ?C2O42– --> ?Mn2+ + ?H2O + ?CO2 what's the balanced equation? correct coefficients? is it 1MnO4- + 2H+ + 1C2O42- --> 1Mn2+ + 1H20 + 2CO2 ? c2042..? are you missing parenthesis somewhere? oh i see, no i believe this is correct: MnO4- +

    asked by christine on April 29, 2007
  15. Economics

    5. (Ch. 17 # 5) Sparkle is one firm of many in the market for toothpaste, which is in long-run equilibrium. a. Draw a diagram showing Sparkle’s demand curve, marginal revenue curve, average cost curve, and marginal cost curve. Label Sparkle’s

    asked by Amanda on April 8, 2007
  16. chemistry

    The vapour denisty of a mixture containing NO2 & N2O4 is 38.3 at 27 deg C. Calculate the moles of NO2 in 100 g of mixture. The vapor density is the mass of a volume of the mixture divided by the mass of an equal volume of H2 at the same P and T. If we take

    asked by sumati on April 10, 2007
  17. math,help

    Is this trinomial a perfect square x^2-6x+9 if the trinomial starts with x^2 and 1/2 of the middle term coefficient squared equals the last term, then it is a perfect square. tell me what you found. i thought it was not a perfect square. because i tried

    asked by jasmine20 on April 19, 2007
  18. physics

    A glass bottle of soda is sealed with a screw cap. The absolute pressure of the carbon dioxide inside the bottle is 1.80 x10^5pa. Assuming that the top and bottom surfaces of the cap each have an area of .0004M^2, obtain the magnitude of the force that the

    asked by CJ on April 8, 2007
  19. physics

    At high noon, the Sun delivers 1000W to each square meter of a blacktop road. If the hot asphalt loses energy only by radiation, what is its equilibrium temperature? so I know that the formula to find the RATE OF RADIATION= the constant (5.6696 x 10^-8

    asked by jean on April 26, 2007
  20. related rates with work shown

    this is a relate rates problem in calculus in a right triangle, the hypotenuse is 5 and the vertical side is x and the angle is theta. so if theta increases at a constant rate of 3 radians per minute, at what rate is x increasing in units per minute when x

    asked by Anonymous on April 15, 2007
  21. Chem 2

    what is the solubility of silver carbonate in water in 25 degrees celcius if Ksp=8.4X10-12? i don't know what to do Write the equation. Ag2CO3(s) ==> 2Ag^+ + CO3^= Ksp = (Ag^+2)(CO3^=) Let x = solubility of Ag2CO3. At equilibrium,(Ag^+) = 2x; (CO3^=) = x.

    asked by joe on April 28, 2007
  22. astronomy

    A line in star's spectrum lies at 400.0 nanometers. In the laboratory, that same line lies at 400.2 nanometers. How fast is the star moving along the line of sight; that is, what is its radial velocity? Is it moving toward or away from us? Since the

    asked by Sethi on April 27, 2007
  23. chemistry

    Write a net ionic equation for the reaction of the aqueous species ammonia and hydrofluoric acid. I don't think mine is coming out right- I don't know how NH3 reacts with other species, because I end up getting hydrogen as both an anion and a cation in the

    asked by Christine on April 29, 2007
  24. Chem

    Which coordination compound will most likely form a precipitate when treated with silver(II) nitrate (aqueous)? [Cr(NH3)3Cl3] [Cr(NH3)6Cl3] Na3[Cr(CN)6] Na3[CrCl6] I tried the solubility rules, but that didn't work out. Any help would be great. I made a

    asked by Londy on April 21, 2007
  25. solving trig. equations

    tan(3x) + 1 = sec(3x) Thanks, pretend 3x equals x so tanx + 1 = secx we know the law that 1 + tanx = secx so tanx + 1 becomes secx and... secx = secx sec(3x) = sec(3x) [just put 3x back in for x- you don't really have to change 3x to x but it kinda makes

    asked by Jen on April 12, 2007
  26. Chemistry

    Hi, I posted yesterday with this lab question. "Calculate the molar amounts of NaOH used in the reaction with the HCl solution and with the HC2H3O2. I think I got the answer to that with the help that I received. I had 5 mL of HCl, and I was using .100 M

    asked by Rachel on April 22, 2007
  27. chem

    a test tube containing CaCo3 is heated until all the compound decomposes. If the test tube plus calcium carbonate originally weighed 30.08 grams and the loss of mass during the experiment is 4.40 grams, what was the mass of the empty test tube? Write the

    asked by laura on April 15, 2007
  28. Somebody answer

    answer questions Ask a question. I have been working on the question for at least an hour. The question is: I have to spend 100 dollers and by 100 brains. Cow brains 5.00 Pigs 2.00 sheep 0.10 I have to buy one of each. I am very confused. Are teacher gave

    asked by dfsfd on April 1, 2007
  29. Econ MC

    !@#$%^& owns a dog whose barking annoys !@#$%^&'s neighbor Jane. !@#$%^& receives personal benefit from owning the dog, and Jane bears a cost of !@#$%^&'s ownership of the dog. Assuming !@#$%^& has the legal right to keep the dog, which of the following

    asked by Econ on April 17, 2007
  30. physics

    35 amps of current goes through a 40 amp fuse. What happens? 25 amps of current goes through a 15 amp fuse. What happens? Think about what a fuse is used for. Why would you put a fuse in a circuit?

    asked by Anonymous on April 13, 2007
  31. chemistry

    Can some one please balance this equation for me Fe + O2---> Fe2O3. Fe + O2 ==> Fe2O3. Here is the way to balance these equations by inspection, meaning, by trial and error. Rule #1. You may not change any subscripts. Equations are balanced by changing

    asked by Biggy Smalls on April 30, 2007
  32. ..physics.

    At 20.0 C, an alumium ring has an inner diameter of 5.0000 cm and a brass rod has a diameter of 5.0500 cm. a. If only the ring is heated, what temperature must it reach so that it will just slip over the rod? b. WHAT IF? If both are heated together, what

    asked by jean on April 19, 2007
  33. Chemistry

    1.Arrange the following oxides in the order of increasing basicity. -Al2O3 -B2O3 -CaO -Ga2O3 -In2O3 -RaO 2.Arrange the following oxides in the order of most basic to most acidic. -Al2O3 -Cl2O7 -Cs2O -N2O5 -Na2O -P2O5 -SO3

    asked by Mark on April 23, 2007
  34. Chemistry

    Explain why acetic acid has four hydrogens, but is a monoprotic acid The formula for acetic acid is CH3COOH so yes it does have four hydrogens. But the only hydrogen that is able to easily come off and be donated to another molecule is the H from COOH and

    asked by John on April 1, 2007
  35. Math

    If 4X + Y =H, Then X is equal to? 4X + Y =H Move Y to other side by subtracting Y from both sides. 4X + Y - Y = H - Y Combine terms. 4X = H - Y Now divide both sides by 4 to get 1X. 4X/4 = (H - Y)/4 X = (H-Y)4 or (1/4)(H-Y)

    asked by Pam on April 16, 2007
  36. Physics (torque, if possible)

    An electric motor turns a flywheel through a drive belt that joins a pulley on the motor and a pulley that is rigidly attached to the flywheel. The flywheel is a solid disk with a mass of 80.0kg and a dimaeter of 1.25m. It turns on a frictionless axle. Its

    asked by Anderson on April 18, 2007
  37. physics

    A rod of length 30.0 cm has linear density(mass-per-length) given by [lambda]= 50.0g/m + 20.0x g/(m^2) where x is the distance from one end, measured in meters.(a) What is the mass of the rod? (b) How far from the x=0 end is its center of mass? never mind.

    asked by jean on April 19, 2007
  38. stat

    the average number of pushups a United States Marine does daily is 300, with a standard deviation of 50. A random sample of 36 marines is selected. What is the probability that the sample mean is at most 320 push-ups? With a mean of 300, you are looking

    asked by Anonymous on April 15, 2007
  39. English

    whats figurative language? Check this site for a great explanation and examples. Thank you for using the Jiskha Homework Help Forum. If you are seeking a definition for "figurative language" it is used

    asked by kev on April 13, 2007
  40. Chemistry

    The complex ions of Zn2+ are colorless. Why? Keith, Natali, Cindy, Joel, or whoever, Please note that we don't do students' homework for them. Our tutors try to give you the information to help you complete your assignment on your own. If there's not a

    asked by keith on April 27, 2007
  41. Physics please check

    Three moles of an ideal monatomic gas are at a temperature of 345 K. Then, 2531 J of heat are added to the gas, and 1101 J of work are done on it. What is the final temperature of the gas? delta U= 3/2nR(T final -T initial) (2531J - 1101J) =

    asked by Mary on April 15, 2007
  42. Chem 2

    Propane (C3H8) burns in oxygen to produce carbon dioxide and water vapor. The balance equation for this reaction is C3H8 + 5O2 ----> 4H20 + 3CO2. What volume of carbon dioxide id produced when 2.8 L of oxygen are consumed? Here are the steps for solving

    asked by Katie on April 27, 2007
  43. Econ MC

    I am having trouble solving this MC. Marylyn and Rebecca sell lemonade on the corner. Each glass costs them $0.05 to make. At the end of the day, they have sold 50 glasses and received a total producer surplus of $12.50. That would mean that Marylyn and

    asked by Econ on April 17, 2007
  44. chem

    Consider the decomposition of ammonium hydrogen sulfide: NH4Hs(s) NH3(g) + H2S(g) In a sealed flask at 25*C are 10.0 g NH4HS, ammonia with a partial pressure of .692 atm, and H2S with a partial pressure of .0532 atm. When equilibrium is established, it is

    asked by Chris on April 9, 2007
  45. math

    The amount of money in an account with continuously compounded interest is given by the formula A = Pert, where P is the principal, r is the annual interest rate, and t is the time in years. Calculate to the hundredth of a year how long it takes for an

    asked by Greg on April 22, 2007
  46. CHemistry

    im not sure how u solve these types of problems... How many moles of NaOH are contained in 200ml of a 0.1M of NaOH? How many grams of NaOH are contained in 500ml of a .5M solution of NaOH? A 0.1 M solution has 0.1 moles of the solute NaOH per liter. You

    asked by Phil on April 21, 2007
  47. physics

    You are riding your bicycle directly away from a stationary source of sound and hear a frequency that is 2.5% lower than the emitted frequency. The speed of sound at the temperature that day is 339 m/s. What is your speed? f = f0(v + vo)/v. Here, vo is the

    asked by Coreen on April 30, 2007
  48. Chemistry - Periodic Trends

    For the isoelectronic series S2-, Cl-, Ar, K+, and Sc3+, which species requires the least energy to remove an outer electron? thanks They all have the same number of electrons (40) in the same shell arrangements, but S(2-) has the least nuclear charge.

    asked by alexa on April 21, 2007
  49. chem

    Barium nitrate is added to a solution of .025 M sodium fluoride. a) At what concentration of Ba+2 does a precipitate start to form? b) Enough barium nitrate is added to make [Ba+2]= .0045 M. What percentage of the original fluoride ion has precipitated?

    asked by chris on April 10, 2007
  50. Physics please check

    The "karat" is a dimensionless unit that is used to indicate the proportion of gold in a gold-containing alloy. An alloy that is one karat gold contains a weight of pure gold that is one part in twenty-four. What is the volume of gold in a 20.0 karat gold

    asked by Mary on April 9, 2007
  51. Economics

    What components of GDP (if any) would each of the following transactions affect? Explain. (b) Aunt Jane buys a new house. (c) Ford sells a Mustang from its inventory. (g) Honda expands its factory in Marysville, Ohio. My Answers: (b) Investment since I

    asked by Sally on April 4, 2007
  52. physics

    In preparation for shooting a ball in a pinball machine,a spring (K=675N/m) is compressed by 0.0690m relative to its unstrained length. The ball(m=0.600kg) is at rest against the spring at point A.When the spring is released, the ball slides (without

    asked by Cavin on April 1, 2007
  53. Physics

    A 3.2 kg block is hanging stationary from the end of a vertical spring that is attached to the ceiling. The elastic potential energy of this spring/mass sytem is 2.2 J. What is the elastic potential energy of the system when the 3.2 kg block is replaced by

    asked by Mary on April 2, 2007
  54. science

    can you inscramble these letters to make 2 words first word 12 letters, 2nd word 5 letters ietnnrncuinvtohte Thank you for using the Jiskha Homework Help Forum again. I answered the first one I saw, which was just before this one!

    asked by katie on April 19, 2007
  55. physics - SHM

    Two sinusoidal waves with identical wavelengths and amplitudes travel in opposite directions along a string with a speed of 11 cm/s. If the time interval between instants when the string is flat is 0.33 s, what is the wavelength of the waves? wavelength =

    asked by COFFEE on April 14, 2007
  56. Chemistry

    How many valence electrons does molybdenum have? (give only 1 answer) Go to this site and look for the electrons available in the outside shells. Click on element #42 and scroll down the menu on the left side until you come to electron configuration.

    asked by Al on April 1, 2007
  57. U.S. History

    What slowed down the United States entrance into World War one? European countries had been fighting wars off and on for many years. There was a strong feeling in the U.S. that we didn't want to be involved in Europe's wars. Germany was not a direct threat

    asked by Felicia on April 6, 2007
  58. Social Studies

    Thank you for using the Jiskha Homework Help Forum. Excellent choice: Mansa Musa commissioned great mosques to be built in Timbuktu, Mali's capital, and in other Mali cities. Under Musa's patronage, Muslim

    asked by SraJMcGin on April 27, 2007
  59. Physics

    Radio amateurs are permitted to communicate on the "10 meter band." What frequency of radio waves corresponds to a wavelengthy of 20m? (The speed of radio wave is 3.00 x 10(8)m/s). Can you help me with setting up the formula? frequency = (wave

    asked by Trey on April 10, 2007
  60. algebra

    A continuously compounded account starts with $1500 in principal. The annual interest rate is 9.1%. What is the balance after 30 years? Help please. Thanks amount= 1500*e^.091*30= 1500 e^2.73 thanks

    asked by George on April 12, 2007
  61. Chemistry

    7.0 ml of 6.0 M NaOH are diluted with water to a volume of 400 ml. You are asked to find the molarity of the resulting solution. The total number of moles of NaOH is not changed on dilution. Calulate the molarity. Work: (6)(.007)=(x)(.4) x=.105M Thanks for

    asked by Anonymous on April 19, 2007
  62. Geometry

    I had to fill out a chart stating the properties of certine shapes(parallelograms). Some of them i put to many properties please tell me witch ones i have wrong. The properties to select from: 1-Opposite sides are parallel (both pair) 2-Opposite sides are

    asked by Roxxxxxxxxx on April 26, 2007
  63. math (statistics)

    There are 15 qualified applicants for 5 trainee positions in a fast-food program. How many groups of trainees can be selected? I have a feeling that the answer is 75 but I'm not too sure. Any help is appreciated. Thank you! The first trainee can be any one

    asked by vivian on April 9, 2007
  64. Chemistry

    Can someone check my answers? These are based off of an experiment which is determining the proportionality constant, R, in the ideal gas equation. 1. Suppose a student runs into some procedural and calculation difficulties. State the effect the following

    asked by Brandon on April 1, 2007
  65. chemistry

    how would you begin this question? An empty 15.0 L cylinder, .500 moles of gaseous PCl5 are added and allowed to reach equilibrium. The concentration of PCl3 is found to be .0220M. (Temp at 375K) PCl3(g) + Cl2(g) --> PCl5(g) i need to fine how many moles

    asked by Anonymous on April 28, 2007
  66. physics - waves

    Two sinusoidal waves, identical except for phase, travel in the same direction along a string producing a net wave y'(x, t) = (1.5 mm) sin(29x - 4.0t + 0.960 rad), with x in meters and t in seconds. (a) What is the wavelength of the two waves? I found the

    asked by COFFEE on April 15, 2007
  67. Chemistry

    What is the molality of a glucose solution prepared by dissolving 18.0g of glucose, C6H12O6 in 125g of water? A)0.000794 B)0.144 C)0.699 D)0.794 Molality is the number of moles of solute per kilogram of solvent. Because the density of water at 25°C is

    asked by CIndy on April 27, 2007
  68. chem. Combined Gas laws

    A gas takes up a volume of 17 liters, has a pressure of 2.3 atm, and a temperature of 299K. If I raise the temperature to 350K and lower the pressure to 1.5 atm, what is the new volume of the gas? Use the combined gas law here. I will be happy to critique

    asked by sam on April 16, 2007
  69. Chemistry

    I wanted to now what is the molecular geometry of SeBr4, because I believe is a trigonal bipyramid...but I am not sure...please help me.... I thought it was a see-saw shape. See You can see SeF4,

    asked by Ross on April 20, 2007
  70. math

    1. The table shows the number of wild strawberry plants in a particular forest t years after a forest fire. Use a graphing calculator to find the exponential function that best fits the set of data. Number of Wild Strawberry Plants years | wild strawberry

    asked by Mary on April 12, 2007
  71. english

    Thank you for using the Jiskha Homework Help Forum. You can learn best with examples. 1. Object pronouns are used everywhere else (direct object, indirect object, object of the preposition). Object pronouns are me, you, him, her, it, us, and them. Examples

    asked by SraJMcGin on April 5, 2007
  72. physics

    A tube is open only at one end. A certain harmonic produced by the tube has a frequency of 445.0 Hz. The next higher harmonic has a frequency of 525.9 Hz. The speed of sound in air is 343 m/s. (a) What is the integer n that describes the harmonic whose

    asked by Cavin on April 29, 2007
  73. Vitamins

    Vitamins that may cause toxicity if ingested in too large amounts are: 1.vitamin A,vitamin C, and thiamin 2.vitamin C, riboflavin, and thiamin 3.vitamin A,vitamin D,and pyridoxin(B6) 4.vitamin D,vitamin C, and B12 Doesn't vitamin A,vitamin D, and

    asked by Gail and Trish on April 20, 2007
  74. English

    Can you help me unscramble these words; dramalanse,ubrocai,planotee,evebra, chorits. they are animal names.Please help!!! thanks Try these: =) unscramble to

    asked by Dora on April 23, 2007
  75. chemisrty

    what is the strongest acid here? H2SO3 H2SO4 H2SeO3 H2SeO4 For oxyacids, the acidity increases with increasing number of oxygen atoms; therefore, H2SO3 and H2SeO3 will be weaker than either H2SO4 or H2SeO4. We have a problem determining which is the

    asked by luis on April 30, 2007
  76. Physics HELP!!!!!!!!

    When an object of mass m1 is hung on a vertical spring and set into vertical simple harmonic motion, its frequency is 12 Hz. When another object of mass m2 is hung on the spring along with m1, the frequency of the motion is 4 Hz. Find the ratio m2/m1 of

    asked by Mary on April 4, 2007
  77. Geography

    What kinds of problems might exist in the Western Cordillera region for farming and transportation? Please help. thanks. Thank you for using the Jiskha Homework Help Forum. Each time you post try to give the complete frame of reference. When you just say

    asked by Karla on April 12, 2007
  78. Geometry

    I had to fill out a chart stating the properties of certine shapes(parallelograms). Some of them i put to many properties please tell me witch ones i have wrong. There are wrong properties listed for some shapes because My teacher said that I have some of

    asked by Roxxy on April 30, 2007
  79. Chemistry

    Use these answers for questions 4 - 7. (A) 1s2 2s22p5 3s23p5 (B) 1s2 2s22p6 3s23p6 (C) 1s2 2s22p62d10 3s23p6 (D) 1s2 2s22p6 3s23p63d5 (E) 1s2 2s22p6 3s23p63d3 4s2 4. An impossible electronic configuration 5. The ground-state configuration for the atoms of

    asked by Rachel on April 12, 2007
  80. Physics please check

    An electric clock is hanging on the wall in the living room. The clock is unplugged, and the second hand comes to a halt over a brief period of time. During this period, what is the direction of the angular acceleration of the second hand? a. clockwise b.

    asked by Mary on April 24, 2007
  81. Math

    If you told someone that the greatest depth of Lake Superior is 1333ft would you be expressing a number similar to mode, median, mean or range? That would be the range. The mode is the numbers that appear most often. Median is the middle number and mean is

    asked by Connor on April 23, 2007
  82. Geography.../what does this mean?

    " The earth's physical landscape is the result of conflict between forces..." Explain what this means. Thanks. Is it possible that forces move Earth around, sometimes the movement is opposing another landforce, they collide, and one slide under?

    asked by Liza on April 3, 2007
  83. AP Chemistry

    This questions has 5 parts but I already have the answers for a and b. I need help on the last three parts. In an electrolytic cell, a current of 0.250 ampere is passed through a solution of a chloride of iron producing Fe(s) and Cl2(g). a) write the

    asked by anonymous on April 24, 2007
  84. CHemistry

    Which one of the following is expected to be the strongest Lewis acid? Fe, Fe+, Fe2+, Fe3+ Which do you think would accept electrons the easier? Fe(s) or Fe^+? Do that same kind of logic on the others one by one.

    asked by Joel on April 27, 2007
  85. physics

    Two radio antennas simultaneously transmit identical signals with a wavelength of 3.35 m. A radio several miles away in a car traveling parallel to the straight line between the antennas receives the signlas. If the second maximum is located at an angle of

    asked by anonymous on April 19, 2007
  86. Physics repost please check

    A lunch tray is being held in one hand, as the drawing illustrates. The mass of the tray itself is 0.280 kg, and its center of gravity is located at its geometrical center. On the tray is a 1.00 kg plate of food and a 0.210 kg cup of coffee. Obtain the

    asked by Mary on April 24, 2007
  87. chemistry

    why would lowering the temp and decreasing the pressure not increase the rate of the reaction: carbon monoxide gas is combusted in the presence of oxygen gas into carbon dioxide. (DeltaH for this reaction is -285kJ.) CO + O2 ==> CO2 + heat decreasing P

    asked by alexa on April 29, 2007
  88. math

    A softball diamond is a square with sides of 60 feet long. How far is home plate to second base? Round to the nearest tenth if necessary. 60 Home plate, first base, and second base form a right-angled triangle, with home plate to second as the hypotenuse.

    asked by ana on April 9, 2007
  89. Physics

    A vertical spring with a spring constant of 450 N/m is mounted on the floor. From directly above the spring, which is unstrained, a 0.30 kg block is dropped from rest. It collides with and sticks to the spring, which is compressed by 3.0 cm in bringing the

    asked by Mary on April 4, 2007
  90. Chemistry

    0.50 M HI with 0.10 M KOH pH at equivalence point? I had another problem like this and I tried to do it the same way b/c I thought that was the right thing to do but it seems as if its not? Can you help? HI + KOH ==> KI + H2O. At the equivalence point we

    asked by Paul on April 2, 2007
  91. Science

    The water in a beaker has a mass of 18g. Electricity is passed through the water for two hours. Afterward the water has a mass of only 16g. What happened to the missing mass? The water heated up due to the electrical current going through it, and some of

    asked by AJ on April 22, 2007
  92. Maths-Vectors Help!

    Please help confirm if I got this problem correctly; 1)2jx(3i-4k) sol>> 2x3jxi - 2x4jxk = 6jxi - 8jxk = 6k - 8i 2) (i-2j)xk Solutn>> ixk - 2jxk = -j - 2i 3) (2i-4k)x(ix2j) solutn>>2ixi Please do help with this ONE yes, correct. On the third, break recheck

    asked by Segun on April 16, 2007
  93. Chemistry

    Describe how you would obtain pure crystals of Sodium chloride from a muxture of solid sodium chloride and solid zinc carbonate Step1 Step 2 Step 3 1. Add HCl to react with the carbonate. The products are zinc chloride, CO2, and water. The CO2 leaves as a

    asked by Ali on April 24, 2007
  94. physics..please help?

    At rest, a car’s horn sound at the note A(440Hz) The horn is sounded while the car is moving down the street. A bicyclist moving the same direction with one third the car’s speed hears a frequency of 415 Hz. What is the speed of the car? Is the cyclist

    asked by sammy on April 10, 2007
  95. Physics HELP!!!!!!!!

    The brass bar and the aluminum bar in the drawing are each attached to an immovable wall. At 29°C the air gap between the rods is 2 x 10^-3 m. At what temperature will the gap be closed? The length of the brass rod is 2.0m The lenght of the aluminum rod

    asked by Mary on April 14, 2007
  96. Chemistry

    Magnesia (MgO) is used for fire brick, crucibles, and furnace linings because of its high melting point. It is produced by decomposing magnesite (MgCO3) at around 1200 oC. 1. Calculate the equilibrium pressure of CO2(g) (in atmospheres) above MgCO3(s) at

    asked by Kegahn on April 6, 2007
  97. english help

    A Midsummer Night's Dream by:William Shakespeare...answer the following Question 1 Who is chosen to play the lion in the craftsmen’s play? Question 2 Which of the young Athenians is first affected by the love potion? Question 3 Who tells Demetrius that

    asked by fanana on April 2, 2007
  98. equilibrium concentration

    A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be ? M. Wouldn't that be 0.002 x 1/11 = ??

    asked by Christine on April 4, 2007
  99. physics.

    Heat engine X takes four times more energy by heat from the hot reservoir than heat engine Y. Engine X delivers two times more work, and it reject seven times more energy by heat to the cold reservoir than heat engine Y. Find the efficiency of heat engine

    asked by jean on April 26, 2007
  100. Math--Area

    Find the area of each regular polygon to the nearest tenth. Octagon with side length of 10 kilometers. Heres what I tried; but I don't know if im on the right track. Area=1/2 * Perimeter* Apothem Perimeter=base of octagon* number of sides Perimeter=10*8=80

    asked by natalie on April 4, 2007