Popular questions and responses by shane
  1. CHEM

    A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.8635 g of CO2 and 0.1767 g of H2O. What is the empirical formula of the compound? i got C3H3O2 IS IT RIGHT?

    asked on March 14, 2013
  2. chem

    Consider the fermentation reaction of glucose: C6H12O6 ----) 2C2H5OH+2CO2 A 1.00-mol sample of C6H12O6 was placed in a vat with excess yeast. If 35.1 g of C2H5OH was obtained, what was the percent yield of C2H5OH?

    asked on March 14, 2013
  3. physics

    A softball of mass 0.220 kg that is moving with a speed of 6.5 m/s (in the positive direction) collides head-on and elastically with another ball initially at rest. Afterward it is found that the incoming ball has bounced backward with a speed of 4.8 m/s.

    asked on December 9, 2009
  4. maths

    The coefficient of x^2 is 69 in the expansion of (1-ax)^24, where a>0. Find the coefficient of x^3.

    asked on August 8, 2013
  5. Science

    Explain why it is necessary for phloem to be alive to be functional,whereas xylem can function as dead tissue:

    asked on March 6, 2013
  6. math

    In a bag there are 3 green apples,5 yellow apples,7 green pears and 2 yellow pears,Simon randomly is taking fruit out of the bag by one by one. How many fruits must he take out in order to be certain that he has at least one apple and one pear of the same

    asked on February 5, 2017

    Write the expression in terms of sine only. 8(sin 2x − cos 2x)

    asked on May 21, 2013
  8. Math Word Problem

    Ron is tiling a countertop. He needs to place 54 square tiles in each of 8 rows to cover the counter. He wants to randomly place 8 groups of four blue tiles each and have the rest of the tiles in white. How many white tiles will Ron need?

    asked on November 16, 2012
  9. maths

    An observer on top of a building 66 metres high,finds the angle of elevation to the top of a taller building to be 34 degrees.The angle of depression to the foot of the same building is 51 degrees.If the buildings are on the same ground level find the

    asked on March 13, 2013
  10. science

    Represent this reaction with balanced chemical equation. Disilane gas (Si2H6) undergoes combustion to form solid silicon dioxide and water.

    asked on November 23, 2012
  11. chemistry

    For the electrolysis of molten potassium bromide: (a) write the equation for the reaction at cathode. (b) write the equation for the reaction at anode. (c) write the equation for the overall reaction.

    asked on September 10, 2014
  12. chemistry

    For the electrolysis of molten potassium bromide: Write the equation for the overall reaction.

    asked on September 7, 2014
  13. Biology

    Explain the role of white blood cells in the body's defense against foreign substances.

    asked on April 5, 2013
  14. statistics

    A music industry researcher wants to estimate, with a 90% confidence level, the proportion of young urban people (ages 21 to 35 years) who go to at least 3 concerts a year. Previous studies show that 21% of those people (21 to 35 year olds) interviewed go

    asked on March 19, 2017
  15. Math algebra

    The radiator in a car is filled with a solution of 60% antifreeze and 40% water. The manufacturer of the the antifreeze suggests that, for summer diving, optimal cooling of the engine is obtained with only 50% antifreeze. If the capacity of the radiator is

    asked on November 24, 2015
  16. accounting

    As of January 1 of the current year, the Grackle Company had accounts receivables of $50,000. The sales for January, February, and March of 2012 were as follows: $120,000, $140,000 and $150,000. 20% of each month’s sales are for cash. Of the remaining

    asked on May 3, 2015
  17. Biology

    What are some of the treatments for coronary artery disease?

    asked on April 5, 2013
  18. physics

    A 2.40 kg mess kit sliding on a frictionless surface explodes into two 1.20 kg parts: 3.78 m/s, due north, and 5.28 m/s, 32.8° north of east. What is the original speed of the mess kit?

    asked on March 11, 2015
  19. maths

    John wishes to determine the height of a flagpole. He takes a sighting of the top of the flagpole from point P. He then moves further away from the flagpole by 20 metres to point Q and takes a second sighting. Given the angle Q is 28 degrees and angle P is

    asked on June 7, 2014
  20. Maths

    The diagonals of a rhombus are 320mm and 240mm in length.Find the angles of the rhombus.

    asked on March 3, 2013
  21. Pre-Calculus

    a ferris wheel is elevated 1 meter above ground. When car reaches the highest point of the Ferris wheel, it's altitude from ground level is 31 metres. How far away from the center, horizontally, is the car when it is at an altitude of 25 meters?

    asked on June 8, 2017
  22. maths

    Write 1/2^1-n in non- fractional form.

    asked on May 19, 2014
  23. maths

    Calculate the arc length that subtends an angle of 55 degree at the centre of a circle with radius r = 5cm.

    asked on September 1, 2013
  24. 7th math

    I have no more than five books in my bag. I need to write an inequality for this, x

    asked on May 16, 2013
  25. Maths

    Find the area of the triangle with sides 8.6 cm, 9.1cm and 9.7cm. First find the size of one of the angles.

    asked on April 29, 2013
  26. Calculus

    Estimate the area under the curve f(x) = x2 + 1 from x = 0 to x = 6 by using three circumscribed (over the curve) rectangles. Answer to the nearest integer.

    asked on March 15, 2016
  27. Math

    Prove the identity: sec^4x - tan^4x = 1+2tan^2x

    asked on November 10, 2014
  28. maths

    Given the quadratic equation y = -x^2 + 2x + 3. a) Will the graph turn upwards or downwards? b) What are the coordinates of x and y intercepts? c) What is the coordinate of the turning point? d) Use your answer in parts (a,b,c and d) to sketch the graph.

    asked on May 10, 2014
  29. maths

    Does the parabola y = -3x^2 + 2x - 1 have a maximum or minimum value?

    asked on September 1, 2013
  30. chemistry

    This balance equation shows the burning of octane in air. 2C8H18 + 25O2 ----> 16CO2 + 18H2O. How many grams of carbondioxide will be produced when 1 mole of octane burns completely?

    asked on August 8, 2013
  31. Maths

    A surveyor measures the angle of elevation of the top of the mountain from a point (P) at sea level as 30 detre along a track which slopes uniformly uphill towards the mountain. From this point, which is 50 metre above sea level, he measures the angle of

    asked on June 20, 2013
  32. maths

    A ship sailing on a course bearing 036 degrees is 5500 metres due south of a lighthouse.If the ship continues on this course,what is the closest distance the ship will come to the lighthouse?

    asked on March 8, 2013
  33. maths

    A lighthouse is 9.6 nautical miles from a ship which bears 156 degrees from the lighthouse.How far is the ship east of the lighthouse?Give answer correct to one-tenth of a nautical mile.

    asked on March 3, 2013
  34. maths

    The vertical angle of a cone is 110 degree and the diametre of its base is 186mm.What is its height?

    asked on March 3, 2013
  35. maths

    The angle between two tangents from a point to a circle is 82 degree.What is the length of one of these tangents if the radius of the circle is 80mm?

    asked on March 3, 2013
  36. chemistry

    Represent this reaction with a balance chemical equation. Solid aluminium hydride is formed by a combination reaction of its two elements.

    asked on November 25, 2012
  37. business communication

    you are in a group that feels very cohesive, so cohesive that it seems to agree readily at every step of a project, without any lengthy discussion or conflict. sometimes you don't agree with decisions, but you do not say anything. which of the following is

    asked on April 20, 2011
  38. Calculus

    Given f(x)=sin(x)-2cos(x) on the interval [0,2pi]. Determine where the function is concave up and concave down, and increasing and decreasing. I have found that the answer for decreasing is (2.68,5.82). All answers are to be in interval notation like that

    asked on June 22, 2010
  39. 12th grade English

    Can you check my essay, it is not done, but I want to see if I'm on the right track? My essay is on Hamlet and the thesis statement: "Domino effect of death" Hamlet: A Chain Reaction of Death In Hamlet, death is seen throughout the play, and is one of the

    asked on December 26, 2009
  40. Physics

    A 17 kg child descends a slide 3.5 m high and reaches the bottom with a speed of 1.5 m/s. How much thermal energy due to friction was generated in this process?

    asked on November 16, 2009
  41. calculus

    A)A lighthouse emits a beam of light that rotates (counterclockwise from a birds-eye perspective) at a constant rate with one full rotation every 10 seconds. 100 feet east of the lighthouse is a long wall running north-south. How fast is the light’s

    asked on October 17, 2019
  42. math and social networking

    what could I use 39000 KB worth of data on in about six minutes of time on my s7 edge cell phone

    asked on September 24, 2017
  43. Cruz

    A ferris wheel is elevated 1 meter above ground. When car reaches the highest point of the ferris wheel it's altitude from ground level is 31 meters. How far away from the center,horizontally, is the car it is at an altitude of 25 meters?

    asked on June 8, 2017
  44. Physics

    A 5.20 g pellet is shot horizontally from a BB gun at a speed of 29.1 m/s into a 20.8 g wooden block. The wooden block is attached to a spring and lies on a frictionless table. If the collision is inelastic and the spring constant k = 22.0 N/m, what is the

    asked on November 14, 2016
  45. Algebra

    The difference between twice a number and a number that is 5 more than 3. Write an equation that could be used to find the value of the number n, and explain how you arrived your choice

    asked on October 16, 2016
  46. Math

    The radiator in a car is filled with a solution of 60% antifreeze and 40% water. The manufacturer of the the antifreeze suggests that, for summer diving, optimal cooling of the engine is obtained with only 50% antifreeze. If the capacity of the radiator is

    asked on November 24, 2015
  47. basic electronics

    3 resistor in parallel have an equivalent resistance of 1000 ohms. If R2 is twice the value of R3 and trice the value of R1, what is the value of R1,R2 and R3? Please show me the sol'n. n_n

    asked on June 14, 2015
  48. Math

    Frank teacher was teaching the class about fractions. She posted the fractions 1/7 and 3/9 on the board. Frank was supposed to answer what the least common multiple of the two fractions was. What did he answer? Help

    asked on January 21, 2015
  49. Chemistry

    I'm stumped 4ko2 + 2co2 ----2k2co3 + 3o2 What mass of k02 in grams is required to react with 8.90 l at 22.0 c and 767 mm hg? Please help thank you

    asked on December 15, 2014
  50. chemistry

    in HNO3 titration, you add few drops of phenolphthalein indicator to 50.0 mL of acid in a flask. you quickly add 20.00 mL of 0.0547 M NaOH but overshoot the end point, and the solutions turn deep pink. instead of starting over, you add 30.00 mL of acid,

    asked on September 27, 2014
  51. maths

    Find the coordinates of the points of intersection of the straight line y = 3x - 6 with the parabola y = x^2 - 6x + 8 and solve Graphically.

    asked on May 12, 2014
  52. maths

    Show by calculations weather the following lines are parallel or not.. y + 5x = 1 and 0.2 = y - 5.

    asked on April 16, 2014
  53. math

    One pump can empty a pool in 5 days, whereas a second pump can empty the pool in 7 days. How long will it take two pumps, working together, to empty the pool?

    asked on November 18, 2013
  54. maths

    Find the line that is perpendicular to y = -3/4 x + 2 and passes through (3,4).

    asked on September 1, 2013
  55. maths

    Find the two stationary points on the curve when y = 2x/x^2 + 1

    asked on September 1, 2013
  56. maths

    A circle x^2 + y^ + 2x - 2y -1 = 0 expressed in the following form (x-h)^2 + (y-k)^2 = r^2 where h, k are the coordinates of the centre. How is r the radius given?

    asked on September 1, 2013
  57. Chemistry

    One step of the Ostwald process for manufacturing nitric acid involves making nitrogen monoxide by oxidizing ammonia in the presence of a platinum catalyst: 4NH3 (g) + 502 (g)>> 4NO (g) + 6H2O (g). If the percentage yield is 80.3%, how many grams of NO can

    asked on June 10, 2013
  58. math


    asked on May 19, 2013
  59. maths

    Please I need help.Show full working out. (a) sin x cot x= cos x (b) (1 + tan theta)^2 + (1- tan theta)^2 = 2sec^2theta

    asked on May 6, 2013
  60. HELP Physics

    The average rate at which energy is conducted outward through the ground surface in a certain region is 30.9 mW/m2, and the average thermal conductivity of the near-surface rocks is 3.11 W/m·K. Assuming a surface temperature of 9.48°C, find the

    asked on April 12, 2013
  61. Biology

    Explain what happens when a person with AB+ donates blood to a patient with A+ blood type?

    asked on April 5, 2013
  62. Chemistry

    (1) Use the thermodynamic values to (a) deduce the enthalpy change of each reaction (b)state if the reaction is exothermic,or endothermic,and also how much energy is released or absorbed. For thi reactions; (1) NH4NO3 (s)------>N2 (g) + 2H2O (l) (2) 4Zn

    asked on March 12, 2013
  63. maths

    Two walkers set off at the same time from a crossroad and walk along flat straight roads inclined to each other at 68 degrees.If they both walk at a speed of 6km/h,find their distance apart 10 minutes later.

    asked on March 10, 2013
  64. maths

    Two walkers set off at the same time from a crossroad and walk along flat straight roads inclined to each other at 68 degrees.If they both walk at a speed of 6km/h,find their distance apart 10 minutes later.

    asked on March 10, 2013
  65. science

    Explain what is meant by source to sink flow in phloem transport.

    asked on March 6, 2013
  66. maths

    A rectangle has sides 170mm and 130mm.What is the angle between the diagonals?

    asked on March 3, 2013
  67. physics

    What is the apparent weight of a lead brick 2.0 in x 2.0 in x 8.0 in if placed in oil with density p=0.93 g/cm^3 (Ppb=11.4 g/cm^3)(1 in. = 2.54 cm)

    asked on January 21, 2013
  68. Chemistry

    Complete and balance the following equations.Identify each type of the reactions. (a) Cr + O2 >Cr2O3: (b)Na2CO3 + Mg3(PO4)2: (c)H3BCO+ H2O> B(OH)3 + CO + H2:

    asked on November 25, 2012
  69. Chemistry

    what is the name of the ions that are formed when the following compounds dissolve in water. (a) BaBr2 (b) (NH4)2CrO4 (c)HBr

    asked on November 23, 2012
  70. Chemistry

    A saturated Ni(OH)_2_ can be prepared by dissolving 0.239 mg of Ni(OH)_2_ in water to make 500.0 mL of solution. What is the Ksp for Ni(OH)_2_?

    asked on March 15, 2012
  71. calculus

    if f(x) = square root of e^2x +1, then then f'(0) equals what?

    asked on March 6, 2012
  72. math

    Danish used 9 balls of clay and 16 straws to make a solid pyramid. How many faces does the solid have?

    asked on March 29, 2011
  73. physics - please help

    A 0.455 kg wood block is firmly attached to a very light horizontal spring (k = 160 N/m). It is noted that the block-spring system, when compressed 5.0 cm and released, stretches out 2.3 cm beyond the equilibrium position before stopping and turning back.

    asked on November 23, 2009
  74. Physics

    A window washer pulls herself upward using the bucket-pulley apparatus shown in Fig. 4-42. The mass of the person plus the bucket is 69 kg.How hard must she pull downward to raise herself slowly at constant speed?If she increases this force by 11 percent,

    asked on October 13, 2009
  75. science

    what material can we use as an indicator of acid?in other words,what material can we use to test a food to see if acid is present? what is the relationship between the concentration of acid in a liquid and the amount of carbon dioxide produced?

    asked on October 15, 2008
  76. Question about PC's

    i have a question on my assignment that I donot understand. Which high performance processor is the fastest Pentium4 or Itanium4? I know there is an Itanium2. But, there isn't a Itanium4 is there? So, wouldn't Pentium4 be the fastest? Yes, the Pentium 4 at

    asked on June 18, 2007
  77. Science

    COMPOUND 1 CH2=CH-CH-OH ________| _______CH3 COMPOUND 2 _____________O ____________// CH3-CH-CH2-C _____|______\ ____CH3______OH *Now, I must: Identify any functional groups in these compounds and name them. The functional group in 1 is the OH which makes

    asked on February 7, 2007
  78. Math

    I need help with Maps and scale The question is : The actual Distance between two cities is and the map scale 100 km find the map distance.

    asked on December 4, 2019
  79. Math

    Which of the following

    asked on December 4, 2019
  80. science

    The substances listed on the left side of a chemical equation are the _____. A.coefficients B.products C.reactants im sayin a but not sure

    asked on May 17, 2019
  81. Chemistry

    Calculate the solubility of the compoud PbI2 in a 0.0333 M solution of Mg(ClO4)2 using (1) activities and (2) molar concentrations

    asked on February 6, 2019
  82. math

    A florist has 78 white roses and 65 red roses. The florist arranges the roses into groups that have the same ratio of white roses to red roses as the whole collection of roses. How many white roses are in a group that has 10 red roses? Complete the ratio

    asked on February 4, 2019
  83. math

    You and your friend collect 180 cans for a food drive. The ratio of cans you collected to cans your friend collected is 4 to 5. Use the tape diagram to find how many cans you collected.

    asked on February 4, 2019
  84. Calculus

    Suppose the population of a colony of ants grows at the rate: P’(x) = 1 + 5/sqroot(t+1) If there are 250 ants after 120 hours, what was the population at t=0?

    asked on April 1, 2018
  85. Calculus

    Suppose the annual revenue for a company between 2000 and 2005 is approximated by R(t)=18t^2+4t+3, where t=0 represents the year 2000.(a)Find the Average Value of R(t) between t=1and t=6. (b)Find the Average Rate of Change of R(t) between t=1 and t=6.

    asked on April 1, 2018
  86. algebra

    Last year, Hans deposited $3000 into an account that paid 5% interest per year and $7000 into an account that paid 4% interest per year. No withdrawals were made from the accounts

    asked on February 24, 2018
  87. Math

    Ethel collects animal stickers.She has 30 cat stickers,15 horse stickers,19 dog stickers and 11 rabbit stickers. One third of the horse stickers are round and the rest are square. One fifth of the cat stickers are square and the rest are round. All the dog

    asked on July 27, 2017
  88. English

    What are two themes in Perseus Adventures? Reading the book but really don't understand the question

    asked on November 2, 2016
  89. Algebra

    The sum of 3 consecutive odd numbers is 63. What is the smallest of these numbers

    asked on October 19, 2016
  90. Global History

    Describe in 7 sentences the significant of each individual. 1. Aryans 2. Asoka 3. Brahmins 4. Confucius 5. Laozi 6. Shi Huangdi 7. Siddhartha Guatama 8. Untouchables 9. Wudi I believe the were all famous rulers but that is all I know

    asked on October 19, 2016
  91. Health

    Identify and define the causes of mental disorders

    asked on October 10, 2016
  92. Algebra

    A rectangle has dimensions in feet as shown in the figure it is 2x +5 And one side is 8. I need to write an expression for the area of the rectangle. B. Find the area of the rectangle, in sq.ft. if x=3 C. Find the value of x if the area of the rectangle is

    asked on October 3, 2016
  93. Math

    An object with initial velocity of 20 m/s accelerates uniformly at 5 m/s in the direction of its motion for a distance of 10 m. What is the final velocity of the object?

    asked on September 27, 2016
  94. government

    We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments

    asked on August 18, 2016
  95. Physics

    A piece of cobalt has a mass of 41 g and is initially electrically neutral. It is then charged with q = +0.6 µC. (a) How many electrons were removed from the piece of cobalt in the charging process (in electron) (b) What fraction of the total number of

    asked on January 18, 2016
  96. Physics

    Determine the magnitude of the force between an electric dipole with a dipole moment of 2 ✕ 10-29 C m and an electron. The electron is positioned r = 25nm from the centre of the dipole, along the dipole axis. Hint: Assume that r >> d, with d the charge

    asked on January 18, 2016
  97. physics

    An object in equilibrium has three forces exerted on it. A 25 N force acts at 90 from the x-axis and a 48 N force acts at 60. What are the magnitude and direction of the third force

    asked on November 29, 2015
  98. Math

    Two cars leave the same town and travel in opposite directions. At the end of 8 hours, the cars are 896 miles apart. Find the rate of each car if the rate of one car is 4 mi/hr more than the rate of the other.

    asked on November 24, 2015
  99. Math

    Gab and Van can mow the lawn in 40 minutes if they work together. If Gab works twice as fast as Van, how long does it take Gab to mow the lawn alone ?

    asked on November 24, 2015
  100. Thermodynamics

    Help me please...! take home quiz >.< A 1Kg of Water at 80 degree Celsius is added to 0.8Kg of water at 20 degree Celsius find the change in entropy.?

    asked on September 3, 2015


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