Most popular questions and responses by Zach
  1. Science

    1.) when might preserved remains of an entire organism form? A.) when sediment buries the hard part of an organism B.) when an event such as a quick burial or freezing preserves an entire organism ******* C.) when minerals replace parts of an organism D.)

    asked on February 29, 2016
  2. Physics

    In a hydroelectric dam, water falls 26.0 m and then spins a turbine to generate electricity. What is ∆U of 1.0 kg of water? Suppose the dam is 80% efficient at converting the water's potential energy to electrical energy. How many kilograms of water must

    asked on November 30, 2009
  3. math

    How does finding the square root of a number compare to finding the cube root of a number? Use the number 64 in your explanation.

    asked on October 31, 2012
  4. Chemistry

    What is the balanced equation for copper (II) sulfate pentahydrate and potassium oxalate monohydrate?

    asked on July 6, 2012
  5. Math. (Didn't understand please help!)

    Suppose 20% of babies born are born early, 50% are born on time, and 30% are born late. A nurse uses a random-number table to find the experimental probability that of 5 births, at least 1 baby will be born early. The digits 0 and 1 represent babies born

    asked on April 11, 2017
  6. Physics

    Batman (mass = 90 kg) jumps straight down from a bridge into a boat (mass = 530 kg) in which a criminal is fleeing. The velocity of the boat is initially +20 m/s. What is the velocity of the boat after Batman lands in it?

    asked on February 25, 2008
  7. physics

    A knight sits on a castle wall during a siege.To while away the time, he notes that boulders catapulted from below land on the top of his wall with a vertical velocity of 9.9 m/s. If he is 35 m above the catapult, what is the initial velocity of the

    asked on September 25, 2015
  8. Social Studies

    where is the moon when you are in a location experiencing a low tide

    asked on February 20, 2016
  9. Organic Chemistry

    I am trying to figure out if I am correct about the solubility of 9-fluorenone in NaOH and diethyl ether and the solubility of benzoic acid in NaOH and diethyl ether 9-fluorenone is soluble in diethyl ether because it can hydrogen bond with water so it is

    asked on February 18, 2013
  10. Physics

    I have one problem I just can't figure out, A machine in an ice factory is capable of exerting 3.30 * 10^2 N of force to pull large blocks of ice up a slope. The blocks each weight 1.21 * 10^4th N. Assuming there is no friction, what is the max angle that

    asked on October 13, 2010
  11. Math (algebra)

    Matt has to bake muffins. He uses x eggs for each 200 grams of flour. If he has to use 900 grams of flour how many eggs will he use? I have to set this up as an algebra problem. I am stuck. Our class is just learning this and I don't understand.

    asked on January 11, 2012
  12. Science HELP PLS

    how are earth and venus similar? how is venus different from earth? provide two similarities and two differences

    asked on February 26, 2016
  13. Physics

    A 120 g ball moving to the right at 4.2 m/s catches up and collides with a 450 g ball that is moving to the right at 1.2 m/s. If the collision is perfectly elastic, what are the speed and direction of each ball after the collision?

    asked on November 30, 2009
  14. Chemistry

    Calculate the DELTA H(rxn), DELTA S(rxn), DELTA S(universe), DELTA G(rxn). For each system below indicate whether DELTA S and DELTA H are positive or negative. Then indicate if the reaction is entropy driven, enthalpy driven or neither. C3H8(g) + 2O2(g) =>

    asked on September 19, 2008
  15. physics

    Two air-track carts are sliding to the right at 1.0 m/s and held together by a string. The spring between them has a spring constant of 140 N/m and is compressed 4.5 cm. The carts slide past a flame that burns through the string holding them together.

    asked on November 30, 2009
  16. math

    The perimeter of rectangle ABCD is 256 inches. It's length is 3 times as long as its width. Find the area of triangle ABC.

    asked on February 14, 2012
  17. physics

    You are on a hike in the mountains. You have 3.03 km left to go before your next campsite. The sun will set in 5.2 h. What average speed must you walk to get to camp at sunset? Answer in units of km/h.

    asked on January 4, 2016
  18. chemistry

    How much iron can be recovered from 25.0 grams of FeO?

    asked on November 11, 2010
  19. Chemistry

    How Many Molecules are contained in 0.25 moles of Fe?

    asked on December 11, 2008
  20. Physics

    A ball swings in a vertical circle at the end of a rope 1.50 m long. When the ball is 35.9° past the lowest point on its way up, its total acceleration is (-22.5 i + 20.2 j)m/s^2. Find radial acceleration?

    asked on September 17, 2011
  21. Algebra

    The school that Trevon goes to is selling tickets to a choral performance. On the first day of ticket sales the school sold 12 adult tickets and 4 student tickets for a total of $188. The school took in $171 on the second day by selling 6 adult tickets and

    asked on December 3, 2009
  22. Chemistry

    A quantity of ice at 0.0 °C was added to 33.6 g of water at 45.0 °C to give water at 0.0 °C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol, and the specific heat is 4.18 J/(g•°C).

    asked on January 26, 2015
  23. Chemistry

    A(n) ____ reaction is one in which oxygen reacts with another compound to form carbon dioxide, water, and heat.

    asked on January 4, 2012
  24. Chemistry

    Calculate the mass of NaCl produced when 5.50 moles of Sodium reacts with excess chlorine gas.

    asked on May 21, 2011
  25. AP Chemistry

    The reaction of 5.1 grams of fluorine with excess chlorine produced 4.5 grams of ClF3. What percent yield of ClF3 was obtained? Answer in unites of %

    asked on December 2, 2015
  26. Chemistry

    If the yield from the reaction of acetic acid with isopentyl alcohol is 45% how many grams of isopentyl acetate are formed from 3.58g of acetic acid and 4.75g of isopentyl alcohol?

    asked on March 18, 2010
  27. Science

    The following table shows the period of revolution of some unknown planets of equal mass. Planet Period of Revolution W 1.9 years X 11.8 years Which of the following best explains which planet is farther from the sun? Planet W, because gravity is inversely

    asked on April 10, 2019
  28. AP Chemistry

    If 400 mL of 3.5 molar HCl solution is added to 200 mL of 2.3 molar NaOH solution, what will be the molarity of NaCl in the resulting solution? Answer in units of M.

    asked on February 24, 2016
  29. Social Stuides

    What is one way that the United Nations shapes world affairs

    asked on September 28, 2015
  30. Chemistry

    If 100.0 mL of 0.171 M Na2SO4 are added to 100.0 mL of 0.889 M Pb(NO3)2, how many grams of PbSO4 can be produced? Equation: Na2SO4 + Pb(NO3)2 = 2NaNO3 + PbSO4

    asked on September 22, 2016
  31. Physics

    A cyclist approaches the bottom of a gradual hill at a speed of 20 m/s. The hill is 4.4 m high, and the cyclist estimates that she is going fast enough to coast up and over it without peddling. Ignoring air resistance and friction, find the speed at which

    asked on February 25, 2008
  32. Chemistry

    Write a net ionic equation for the reaction that occurs when aqueous solutions of barium hydroxide and hypochlorous acid are combined.

    asked on September 24, 2017
  33. physics

    A 57.5-kg runner has a speed of 5.80 m/s at one instant during a long-distance event. (a) What is the runner's kinetic energy at this instant? 967.15 J (b) If he doubles his speed to reach the finish line, by what factor does his kinetic energy change? im

    asked on October 5, 2015
  34. physics

    Your car is stuck in a mud hole. You are alone but you have a long strong rope. having studied physics you tie the rope tautly to a telephone pole and pull on it sideways at the midpoint as shown. Find the force exerted by the rope on the car when the anle

    asked on November 23, 2015
  35. math

    A roulette wheel has 18 red slots and 18 black slots numbered alternaetly with the numbers 1 through 36. Two green slots are numbered 0 and 00. The winning number is determined by the slot into which a single marble rolls. Players are not allowed to bet on

    asked on September 18, 2010
  36. Chemistry

    How would I figure out what is produced during a chemical reaction between 0.5 grams of sodium bicarbonate and 3 grams of citric acid? I know that it produces carbon dioxide and water but my professor said I am missing something from my equation.

    asked on June 26, 2012
  37. science

    What is the variable x in the following hydrate formula NaCl xH2O if the mass of sodium chloride is 58g and the mass of the water is 36g

    asked on November 29, 2018
  38. Statistics

    Free Throw Freddie is an 80% free throw shooter. At the end of practice he shoots until he makes 10 shots. a) What is the probability that Freddie makes 10 in a row? b) What is the probability that Freddie needs 15 or more attempts? I understand how to do

    asked on September 11, 2016
  39. physics

    Two blocks are arranged at the ends of a massless string as shown in the figure. The system starts from rest. When the 4.01 kg mass has fallen through 0.412 m, its downward speed is 1.3 m/s. The acceleration of gravity is 9.8 m/s 2 .

    asked on December 9, 2015
  40. Physics

    The 1.1 kg physics book is connected by a string to a 250 g coffee cup. The book is given a push up the slope and released with a speed of 2.9 m/s . The coefficients of friction are μs =0.50 and μk =0.20. What Distance does it travel up the slope? I drew

    asked on October 7, 2015
  41. English

    What is the simple subject of ,Many stories about the first Valentine's Day exist?

    asked on September 5, 2012
  42. Physics

    A cyclist approaches the bottom of a gradual hill at a speed of 20 m/s. The hill is 4.4 m high, and the cyclist estimates that she is going fast enough to coast up and over it without peddling. Ignoring air resistance and friction, find the speed at which

    asked on February 25, 2008
  43. Math

    A 15-g sample of radioactive iodine decays in such a way that the mass remaining after t days is given by m(t) = 15e^(−0.051t), where m(t) is measured in grams. After how many days is there only 3 g remaining?

    asked on April 22, 2013
  44. Algebra

    -6h + 4 - 3 + h = 11 4-3-11=6h-h -10=5h -2=h

    asked on September 21, 2006
  45. math

    With income earned by selling the rights to his life story, an actor invests some of the money at 3% and 30,000 more than twice as much at 4%. The total annual interest earned from the investments is $5600. How much is invested at each rate?

    asked on April 21, 2010
  46. Physics

    A 60-cm-long, 500 g bar rotates in a horizontal plane on an axle that passes through the center of the bar. Compressed air is fed in through the axle, passes through a small hole down the length of the bar, and escapes as air jets from holes at the ends of

    asked on November 30, 2009
  47. Physics

    A 10-g bullet is shot vertically into a stationary 8-kg block. The block lifts upward 3.0 mm. The bullet penetrates the block in a time of .001 seconds. Assume the force exerted on the block is constant. What is the impulse imparted on the block by the

    asked on November 30, 2011
  48. Science

    Which of the following best explains which planet is farther from the sun? Planet W, because gravity is inversely proportional to the square of distance Planet X, because gravity is inversely proportional to the square of distance Planet X, because the sun

    asked on April 10, 2019
  49. Chemistry

    Draw the Lewis structure for each of these molecules. 1. PH3 2. H2S 3. HCl 4. CCl4 5. SiH4

    asked on January 28, 2015
  50. Math

    The map of a biking trail is drawn on a coordinate grid. The trail starts at P(−3, 2) and goes to Q(1, 2). It continues from Q to R(1, −1) and then to S(8, −1). What is the total length (in units) of the biking trail? 11 13 14 16

    asked on November 27, 2017
  51. Math

    The cost of producing x units of a product is given by C(x)=800+120x−120ln(x),x≥1. Find the minimum average cost, which is defined as C(x)/x (the total cost divided by the number of units). Minimum Average Cost =

    asked on January 24, 2017
  52. physics

    A golfer imparts a speed of 40.0 m/s to a ball, and it travels the maximum possible distance before landing on the green. The tee and the green are at the same elevation. (a) How much time does the ball spend in the air? (b) What is the longest "hole in

    asked on January 27, 2018
  53. Physics

    You are installing a new spark plug in your car, and the manual specifies that it be tightened to a torque that has a magnitude of 45 N·m. Using the data in the drawing, determine the magnitude F of the force that you must exert on the wrench. Lenght of

    asked on March 24, 2008
  54. Physics

    The earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. Assuming the earth is a sphere with a radius of 6.38 106 m, determine the speed and centripetal acceleration

    asked on March 3, 2008
  55. Math

    Write an inequality and solve. Two times the sum of a number and four is no more than three times the sum of the number and seven decreased by four.

    asked on July 19, 2018
  56. physics

    An 8 g bullet is shot into a 4.0 kg block, at rest on a frictionless horizontal surface. The bullet remains lodged in the block. The block moves into a spring and compresses it by 7.9 cm. The force constant of the spring is 1400 N/m. What is the impulse of

    asked on November 6, 2012
  57. physics

    A museum curator moves artifacts into place on many different display surfaces. Use the values in Table 4-2 in the textbook to find Fs,max and Fk if you were to move a 157 kg aluminum sculpture across a horizontal steel platform. Fs,max: Fk:

    asked on November 18, 2010
  58. physics

    What is the magnitude of F? Assume the acceleration due to gravity is 9.8 m/s 2 and the surface is frictionless. Answer in units of N.

    asked on December 9, 2015
  59. Science

    Predict what would happen to a reptile body temperature if the outdoor temperature increases by 10c.

    asked on March 16, 2009
  60. phyiscs

    A 14.5 kg toy car is driving around a horizontal circular track with a period of 8.0 seconds. The radius of the circular track is 1.1 meters. What is the force of friction in Newtons between the car and the track that is necessary for the car to remain on

    asked on May 7, 2018
  61. chemistry

    What products are formed when aqueous solutions of Na2SO4, Fe3SO42, and BaCl2 are mixed together ? Can someone help me write out a balanced equation for the reaction that occurs.

    asked on January 24, 2012
  62. Physics

    A mass-spring system has b/m = ω0/2, where b is the damping constant and ω0 the natural frequency. How does its amplitude A when driven at a frequency 12% above ω0 compare with its amplitude at resonance Ares at ω0?

    asked on November 12, 2012
  63. geometry

    Given the points K=(-2,1) and m(3,4), find coordinates for a point J that makes angle JKM a right angle.

    asked on September 8, 2011
  64. College Chemistry

    1) The concentration of the aluminum ion in a test solution is 0.10M. Using the Ksp for aluminum hydroxide (3. x 10^-34), calculate the concentration of hydroxide needed to precipitate aluminum hydroxide. From the concentration of the hydroxide, calculate

    asked on April 1, 2010
  65. math

    A magician has 3 more red hats than black hats and 4 fewer purple hats than black hats and has 14 hatsin all. How many hats of each color does he have. Show how you got the answer.

    asked on September 14, 2009
  66. Chemistry

    A sample of gas contains 0.1900 mol of HBr(g) and 9.500×10-2 mol of Cl2(g) and occupies a volume of 11.2 L. The following reaction takes place: 2HBr(g) + Cl2(g)2HCl(g) + Br2(g) Calculate the volume of the sample after the reaction takes place, assuming

    asked on October 8, 2017
  67. Physics

    An automatic drier spins wet clothes at an angular speed of 4.8 rad/s. Starting from rest, the drier reaches its operating speed with an average angular acceleration of 3.6 rad/s2. How long does it take the drier to come up to speed?

    asked on March 6, 2008
  68. social studies

    what are 2 unwritten practices of the roman republic?

    asked on January 9, 2013
  69. Physics

    A certain dog whistle operates at 23.5 kHz, while another (brand X) operates at an unknown frequency. If neither whistle can be heard by humans when played separately, but a shrill whine of frequency 9200 Hz occurs when they are played simultaneously,

    asked on April 23, 2012
  70. Physics

    A 34-g bullet traveling at 120m/s embeds itself in a wooden block on a smooth surface. The block then slides toward a spring and collides with it. The block compresses the spring (k=100 N/m) a maximum of 1.25 cm. Calculate the mass of the block of wood.

    asked on January 5, 2012
  71. Organic Chemistry

    Melting Point Determinations between urea and trans-cinnamic acid. Q. If urea were a significant base, specifically how would your Melting Point Diagram be different?

    asked on September 23, 2012
  72. chemistry

    PLEASE NOTE: Titration requires several steps in order to obtain exact results. The procedures described in this lab assume that you have already done the TITRATION TUTORIAL and are familiar with the technique. 1. Prepare the NaOH solution by dissolving

    asked on April 15, 2011
  73. physics

    Approximate the gravitational force of attraction between a 49.0 kg girl and a 52.0 kg boy if they are sitting 2.5 m apart

    asked on February 7, 2011
  74. Physics

    A tennis ball may leave the racket on a serve by a top player with a speed of 45.0 m/s. If the ball's mass is 0.063 kg, and it is in contact with the racket for 0.030 s, what is the average force (in newtons) on the ball?

    asked on July 12, 2013
  75. Geometry

    find the lengths of the sides of a triangle whose perimeter is 37. The measure of the first side of the triangle is 8 less than the second side, and the second side is twice the length of the third side

    asked on February 10, 2011
  76. Math

    your aunt gives you a check on your birthday each year. on your first birthday , she gives you a check for one cent. the next year she gives you 3 cents , then 9. each year she triples the amount of the previous year 's check. how old will you be when she

    asked on September 11, 2011
  77. Physics

    A 5.50 kg cat leaps from the floor to the top of a 94.0-cm-high table. If the cat pushes against the floor for 0.220 s to accomplish this feat, what was her average power output during the pushoff period?

    asked on November 30, 2009
  78. Algebra 1

    Mary's class took two tests last week. 80% of the class passed the math test, 90% of the class passed the English test, and 72% of the class passed both. What is the probablility that a randomly selected student in Mary's class failed both tests? Express

    asked on November 5, 2009
  79. Physical Science

    What are the 4 nuclear forces? Out of the 4 which one is the strongest and which one is the weakest? Thanks THANK YOU As a side note, these are not nuclear forces. They are the four fundamental

    asked on April 11, 2007
  80. Social Studies (Check my answers please!)

    What did the Mayan caldenders track? 1. Religous celebrations and battles 2. Religous celebrations and the seasons ** 3. Games of pok-ta-tok and the seasons 4. Games of pok-ta-tok and battles The Aztech capital of Tenochtitlan stood on the site of

    asked on March 27, 2017
  81. English

    When Bruno presumes that ''heil Hitler'' is another way of wishing someone a pleasant afternoon, what literary element is suggested?

    asked on May 1, 2019
  82. Algebra 2

    write the compound inequality 3.1 less then or equal to m less than or equal 4.7 as an absolute value inequality.

    asked on December 16, 2014
  83. Math

    What is the annual interest rate if $1600 is invested for 6yrs. and 456 in intrest is earned

    asked on November 9, 2011
  84. Math

    Amy went to the fall festival and bought at least 25 apples. The apples were a mix of gala apples and red delicious apples. Amy knows that she got more than twice as many gala apples as she did red delicious apples. This can be represented by the system

    asked on July 24, 2018
  85. chemistry

    When 1988 J of heat energy is added to 47.5 g of hexane, C6H14, the temperature increases by 18.5 °C. Calculate the molar heat capacity of C6H14.

    asked on April 7, 2013
  86. Chemistry

    The reaction for my lab is Mg(s)+2HCl(aq)--> MgCl2(aq)+H2(g) I need to find the pressure of the hydrogen gas. Initial Pressure = 0.98692 atm Total Pressure = 1.64816 atm I don't know if I calculated the pressure of hydrogen gas correctly. I used the

    asked on July 15, 2012
  87. Pre Calc (For Reiny)

    Thanks so much your method worked perfectly! My solution was: the remaining zeros were 5+2i, 3, and -4 I have one question that's bugging me though, why is it that synthetic division did not work for me? I thought that long division and synthetic division

    asked on November 15, 2009
  88. Chemistry

    Which stage of ionization usually produces more ions?

    asked on May 27, 2009
  89. Chemistry

    0.250 g KCN is dissolved in 50 mL of water, and added to 2 mL of NaOH then mixed with 48mL of water. What is the molar concentration of KCN? I am stuck on this question. So far I have: 0.250gKCN/0.050L= 5M(g/L) Moles of KCN: 5M = mol/0.05L = 0.25mol KCN I

    asked on September 28, 2016
  90. chemistry

    How many grams of solid ammonium chloride should be added to 1.50 L of a 0.224 M ammonia solution to prepare a buffer with a pH of 8.720 ?

    asked on April 3, 2015
  91. MATH


    asked on February 21, 2012
  92. Algebra II

    The intensity of illumination at a given point is directly proportional to the intensity of the light source and inversely proportional to the square of the distance from the light source. If a desk is properly illuminated by a 74.0 w lamp 8.00 ft from the

    asked on November 21, 2011
  93. math

    Graph the linear equation. -3x + y = -6

    asked on May 5, 2010
  94. Chemistry

    ΔT = T(mix) - T(initial) And the equations is: HCl(aq)+ NaOH(aq) => NaCl(aq) + H2O(l) And T(mix) = 37 C 50.0 mL of 2.0M HCl = 23.7 C 50.0 mL of 2.0M NaOH = 23.5 C How do I find T(initial), do I just use their averages? Thanks

    asked on September 29, 2008
  95. Physics

    A 97.0-kg person stands on a scale in an elevator. What is the apparent weight when the elevator is (a) accelerating upward with an acceleration of 1.70 m/s2, (b) moving upward at a constant speed, and (c) accelerating downward with an acceleration of 1.80

    asked on February 18, 2008
  96. Chemistry

    I am not sure if I calculated the exact molarity of the potassium permanganate. I multiplied the molarity of the potassium permanganate by the liters of potassium permanganate used in the titration and divided it by the total liters of solution. I don't

    asked on November 28, 2012
  97. Geometry

    Help I need help to find the coordinates of the circumcenter of each triangle. Isosceles triangle CDE with vertices C(0, 6), D(0, –6), and E(12, 0)

    asked on November 15, 2012
  98. Science

    The products of the reaction between zinc and sulfuric acid are zinc sulfate, hydrogen sulfide, and water. Balance the equation using the electron-transfer method.

    asked on November 6, 2012
  99. Chemistry

    How would I find the percent of water lost in alum after it has dried for a week? Wet Alum = 13.44g Dry Alum = 11.28g

    asked on September 11, 2012
  100. Algebra 2

    A Rectangular Field is to be enclosed by a fence and divided into three parts by another fencer. Find the maximum area that can be enclosed and separated in this way with 500 meters of fencing.

    asked on February 3, 2011


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