1. physics

    A)Eddie the Eagle, British Olympic ski jumper, is attempting his most mediocre jump yet. After leaving the end of the ski ramp, he lands downhill at a point that is displaced 53.0 m horizontally from the edge of the ramp. His velocity just before landing
  2. Physics

    Eddie the Eagle, British Olympic ski jumper, is attempting his most mediocre jump yet. After leaving the end of the ski ramp, he lands downhill at a point that is displaced 62.2 m horizontally from the edge of the ramp. His velocity just before landing is
  3. Physics

    A test rocket is fired vertically upward from a well. A catapult gives it an initial speed of 80.2 m/s at ground level. Its engines then fire and it accelerates upward at 4.20 m/s2 until it reaches an altitude of 960 m. At that point its engines fail, and
  4. Chemistry

    Propane gas (C3H8) burns completely in the presence of oxygen gas (O2) to yield carbon dioxide gas (CO2) and water vapor (H2O). Write a balanced equation for this reaction. Assuming that all volume measurements occur at the same temperature and pressure,
  5. Chemistry

    Propane gas (C3H8) burns completely in the presence of oxygen gas (O2) to yield carbon dioxide gas (CO2) and water vapor (H2O). Write a balanced equation for this reaction. Assuming that all volume measurements occur at the same temperature and pressure,
  6. Chemistry (Regents level)

    1- In the reaction Fe2O3 + 3 CO = 2 Fe + 3 CO2, what is the total number of moles of CO used to produce 112 grams of iron? a) 1.0 b)2.0 c)3.0 d)4.0 2- Given the reaction: 4Al + 3O2 = 2Al2O3 How many moles of Al2O3 will be formed when 27 grams of Al reacts
  7. Chemistry

    A student mixes 5.0 mL of 0.00200 M Fe(NO3)3 with 5.0 mL 0.00200 KSCN. She finds that the concentration of FeSCN2+ in the equilibrium mixture is 0.000125 M. Follow these steps to determine the corresponding experimental value of Kc for the reaction of Fe3+
  8. chem

    For the following reaction, 31.1 grams of diphosphorus pentoxide are allowed to react with with 10.2 grams of water. diphosphorus pentoxide (s) + water (l)>>> phosphoric acid (aq) What is the maximum amount of phosphoric acid that can be formed in
  9. PSYCHOLOGY am i correct

    The following table describes five situations in which a person reacts to stress in an unhealthy manner. For each: a. identify the stressor(s). b. briefly explain why the person's reaction is an unhealthy choice. c. briefly describe one healthy alternative
  10. Physics

    A red ball is thrown directly upwards from the ground with an initial velocity of 35.0 m/s. At the same time, a blue ball is thrown directly upwards from he ground with an initial velocity of 10.0 m/s. 1. How high is the red ball when the blue ball reaches
  11. Thermodynamics

    Steam in a cylinder-piston arrangement expands from an initial condition of 5 bar, 80% dry to a final state of 2 bar, dry saturated steam. The initial volume of steam is 0.8 m3. The process of expansion can be represented by a straight line on the
  12. Math/Euler's Method

    Consider a cooling cup of coffee whose initial temperature is 205°. The room temperature is held at 70°. Suppose k = 1/16. Let y be the temperature, and y' its time derivative. ----------------------------------- I have the differential equation: y' =
  13. chemistry

    Which factors below affect the rate of a chemical reaction? -Collision frequency -Number of collisions having the least activation energy -Intermolecular orientation -Being Exothermic or Endothermic Also, what formula would I use for this problem: "What is
  14. Chemistry

    The rate law for the reaction NO + O3 > NO2 is rate= k[NO][O3]. What will the effect on the reaction rate if the partial pressure of NO is doubled? What will the effect if the partial pressure of O2 is tripled? Just for clarification: NO will be doubled
  15. chemsitry

    A sample consisting of 0.025 mol of a solid compound is placed inside a metal cylinder. The cylinder was immersed in a water bath consisting of 10.00 kg of water at an original temperature of 25.00 °C. When the compound decomposes, the temperature of the
  16. physics

    A 22.0-L tank of carbon dioxide gas (CO2) is at a pressure of 9.40 105 Pa and temperature of 22.0°C. (a) Calculate the temperature of the gas in Kelvin. K (b) Use the ideal gas law to calculate the number of moles of gas in the tank. mol (c) Use the
  17. Chemistry

    If air is 20% oxygen, and the reaction is 2C2H2 + 5O2 --> 4CO2 + 2H2O, What volume of oxygen would be needed to completely burn 1.00 L of acetylene (C2H2)? I got 2.50 L but I'm not sure it's right. What volume of air would be needed to completely burn
  18. Physical Chemistry

    Calculate the concentrations of each of the following solutions. (a) the molality of chloride ions in an aqueous solution of iron(III) chloride for which xFeCl3 is 0.0195 (b) the molality of hydroxide ions in a solution prepared from 9.16 g of barium
  19. physics

    Part 1 A motorist traveling at 17 m/s encounters a deer in the road 48 m ahead. If the maximum acceleration the vehicle’s brakes are capable of is −5 m/s^2, what is the maximum reaction time of the motorist that will allow her or him to avoid
  20. Chemistry

    Does sodium metal react with potassium hydroxide solution? No. It would be a displacement reaction and this only works if the metal is higher in the activity series than the one it wants to displace. Given that potassium is the highest ranked metal (sodium
  21. Algebra - word problem

    A red ball and a green ball are simultaneously tossed into the air. The red ball is given an initial velocity of 96 feet per second, and its height, t seconds after it is tossed is (-16t^2 + 96t) feet. The green ball is given an initial velocity of 80 feet
  22. physics

    A car is traveling at a constant velocity of 21 m/s (about 45 mph). The driver sees a fallen tree lying across the road and hits the brakes after a delay (reaction time) of 245 ms. (1 ms = 10-3 s.) Calculate the distance the car travels during this 245 ms
  23. P-Chem

    Protein denaturations are usually irreversible but may be reversible under a narrow range of conditions. At pH 2.0, at temperatures ranging from about 40 degrees celcius to 50 degrees celcius, there is an equilibrium between the active form P and the
  24. AP Chemistry

    The reaction of the molecules to produce ethane is C2H4(g) + H2(g) → C2H6(g). A mechanism for this reaction is shown below: (The figures show how the ethene molecule with two hydrogen molecules attached 'binds' to
  25. Chemistry -Please Help

    2. What is the reduction half-reaction for the following unbalanced redox equation? Cr2O7^2– + NH4^+ Cr2O3 + N2 A.) Cr2O3 -> Cr2O7^2– B.) Cr2O7^2– -> Cr2O3 C.) NH4^+ -> N2 D.) N2 -> NH4^+ I think it is B...? 3. Which oxidation-reduction
  26. Science

    The Haber-Bosch process, devised in the early 20th century, revolutionized global industry. It provides a way of “fixing” atmospheric nitrogen into ammonia, allowing for the production of fertilizers and the many nitrogen-based chemicals we use today.
  27. Chemistry

    Question: A solution of H2X of unknown concentration is given. pH of the solution is 4. ka1=2*(10)^-6 M ka2=1*(10)^-11 M Find the concentrations of [H2X] ,[HX-] and X^2- in the solution. My thoughts on the question: The temperature which the solution is
  28. physics

    An electron is projected with an initial speed of (1.90x10^6 m/s) into the uniform field between two parallel plates. Assume that the field between the plates is uniform and directed vertically downward, and that the field outside the plates is zero. The
  29. Physics

    Totally confused on this question, Please help. 1)In the movie The avengers, Captain America sees an alien speeder incoming. The speeder passes directly overhead at 3.65m. If he throws his shield straight up with a speed of 7.40 m/s from a height of 1.55 m
  30. chemistry

    1.equillibrium constant only changes for change in temp? not for change in pressure etc. 2. rate of reaction can be measure by measuring how long it takes for products to form or how long it takes for reactants to be consumed? so is the rate of consumption
  31. PHYSICS

    Two spheres are launched horizontally from a 1.1m -high table. Sphere A is launched with an initial speed of 5.0M/S . Sphere B is launched with an initial speed of 3.0M/S A. What is the time for the sphere A to hit the floor? and sphere B to hit the ground
  32. Chemistry

    I have a few questions, if anyone can help me at all it would be amazing. i need this done by TOMORROW (03/03/2008) 1. Cyanogen has been observed in the atmopshere of Titan, Saturn's largest Moon, and in the gases of the interstellular nebulas. On Earth,
  33. Chem

    I have a few questions, if anyone can help me at all it would be amazing. i need this done by TOMORROW (03/03/2008) 1. Cyanogen has been observed in the atmopshere of Titan, Saturn's largest Moon, and in the gases of the interstellular nebulas. On Earth,
  34. chemistry

    Nitrogen (N2) and hydrogen (H2) react to form ammonia (NH3). Consider a mixture of six nitrogen molecules and six hydrogen molecules in a closed container. Assuming the reaction goes to completion, what will the final product mixture be? number of NH3
  35. Chemistry

    My Chem professor is out for the weekend and I'm confused about what the question is asking or the equations needed... A 10.0-g block of pure nickel (Cp = 0.445 J/g-°C) is brought to each of the temperatures below. A sealed beaker containing 15.0 g water
  36. Soil Chemistry

    Global temperatures are increasing and this increase is probably due to increasing concentrations of greenhouse gases present in A) the troposphere which absorbs outgoing IR radiation B) the stratosphere which absorbs outgoing IR radiation C) the
  37. chemistry

    Urbium (Ur) is an upscale element found in big cities. Its oxide (UrO2) is not very stable and decomposes readily at temperatures exceeding 66∘ C. The figure below shows how the rate of reaction varies with the concentration of UrO2 at 75∘ C.
  38. Chemistry

    Hi, I have another question... I need to write a reaction for the preparation of americium by reducing AmF3 with barium vapor at 1100C I'v looked and can't find anything that will help me with this... (I'm preparing for finals, so this might not be my last
  39. Chemistry

    Thanks to Dr. Bob for answering all these questions! I always do poorly on conceptual problems. Consider the following equilibrium system at 25°C and select the true statement below: H2PO4−(aq) + SO42−(aq) ↔ HSO4−(aq) + HPO42−(aq) ΔG°rxn >
  40. CHEMISTRY

    Urbium (Ur) is an upscale element found in big cities. Its oxide (UrO2) is not very stable and decomposes readily at temperatures exceeding 66∘ C. The figure below shows how the rate of reaction varies with the concentration of UrO2 at 75∘ C.
  41. chemistry

    A 40-year old man, at a prominent legal firm experiences abdominal pain post lunch. He takes several trips to the restroom, but continues to experience pain and cramps. He decides to go to the doctor and admits he consumed 2 bottles of beer @ lunch. The
  42. physics

    1. a) using heat exchange and conservation of thermal energy determine the specific latent heat of fusion for ice. b) determine the percentage error The data we determined was: Hot water: mass - 0.1kg initial temp-87C final temp - 56 C Melted ice: mass -
  43. physics

    hi, reading over momentum notes and i just want to clarify a few things. if i had a system containing a cart that was moving (cart 1) and then a cart that was stationary (cart2)would there be any net external force acting on the system between the initial
  44. algebra

    The number of bacteria in a certain population increases according to a continuous growth model, with a growth rate parameter of 25% per hour. An initial sample is obtained from this population, and after six hours, the sample has grown to 7081 bacteria.
  45. Chemistry

    If 2.00 mL of 0.600 M NaOH are added to 1.000 L of 0.850 M CaCl2, what is the value of the reaction quotient and will precipitation occur? I've been trying this problem over and over and haven't been able to get it. I know precipitation will not occur from
  46. chem

    a) Co(H2O)6^2 + 4 Cl^‐1 (aq) ⇄ CoCl4^‐2 (aq) + 6 H2O (l) Rewrite the net ionic equation above including the energy term where appropriate. The Delta H for this reaction is +50 kJ/mol. b) Silver chloride (AgCl) is a white solid. For the
  47. College Algebra

    The hydrogen ion concentration of a substance is related to its acidity and basicity. Because hydrogen ion concentrations vary over a very wide range, logarithms are used to create a compressed pH scale, which is defined by pH=-log(H+)where (H+)is the
  48. Maths

    Solve the initial value problem (dx/dt)+2x=cos(2t) with x(0)=5
  49. Differential Equation

    Solve the following initial-value problem: y"+6y'+5y=0; y(0)=0. y'(0)=3
  50. Calculus

    solve second-order initial value problem y"(x)= x e^-2x y'(0)= 0 y(0)= 0
  51. chemistry

    How do I calculate the initial concentraion of an acid?
  52. math

    solve the initial value problems: 1- dq/dz = 2 + sinz, q(0)=5 2-dy/dx = (x^2 -2)x, y(2)=4 3-dy/dx = 4e^5^x + x, y(0)=4 4- dy/dx 3x + 2, y(3)= 2
  53. Calculus

    Solve the initial value problem. dy/dx = 3 sinx and y = 2 when x = 0. Is this c = 5?
  54. Math

    Find the first three iterates of the function f(x)=x^2-2,if the initial value is -2.
  55. calculus

    solve the initial value problems: 1- dq/dz = 2 + sinz, q(0)=5 2-dy/dx = (x^2 -2)x, y(2)=4 3-dy/dx = 4e^5^x + x, y(0)=4 4- dy/dx 3x + 2, y(3)= 2
  56. Chemistry

    Given the reactant side of the total ionic equation for the neutralization reaction of ammonium hydroxide (NH4OH) with hydrochloric acid (HCl), write the total ionic equation (also known as the complete ionic equation) by entering both the reactant and the
  57. Chemistry

    A 40-year-old manager, at a prominent legal firm in L.A., experiences abdominal pain post lunch. He goes to the restroom a couple of times, but continues to experience pain and cramps. He eventually decides to get himself examined. While questioning him,
  58. Chemistry

    The following reaction exhibits the rate law: Rate = k[NO2]^2[Cl2]. 2NO(g)+Cl2(g)---->2NOCl (g) (a) Explain why the following mechanism is not plausible for this reaction. Fast: NO + Cl2<-->NOCl + Cl Slow: NO + Cl---->NOCl (b) Propose a
  59. chemistry

    In one experiment, the reaction of 1.00 g mercury and an excess of sulfur yielded 1.16 g of a sulfide of mercury as the sole product. In a second experiment, the same sulfide was produced in the reaction of 1.50 g mercury and 1.08 g sulfur . What mass of
  60. Science

    The rate law for the reaction NO + O2 > NO2 is R=k[NO][O2]. what will be the effect on the reaction rate if the partial pressure of NO is doubled? What will the effect be if the partial pressure of O2 is tripled? My answer: More NO2 would be produced if
  61. Chemistry

    a redox reaction is a reaction in which 1.only reduction occurs 2.only oxidation occurs 3.reduction&oxidation occur at the same time 4.reduction occurs first and then oxidation occurs i think its 3 or 4.
  62. chemistry

    consider the following changes at constant temperature & pressure H2O(s) --yields-- H20(l); Delta H1 H2O(l) --yields-- H2O(g); Delta H2 H2O(g) --yields-- H2O(s); Delta H3 Using Hess's law, the sum of the deltas is a. equal to 0 b. sometimes greater than
  63. economics

    Q: The market demand and supply curves for an agricultural product are as follows: Qd = 4500-250P and Qs = 200p where quantities are in thousands of bushels per annum and price is in dollars per bushel. the government wishes to acheive a higher point on
  64. physics

    A red ball is thrown down with an initial speed of 1.4 m/s from a height of 28 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.9 m/s, from a height of 0.9 meters above the
  65. physics

    I have another question for the problem below, so What is the speed of the car just before it lands safely on the other side? would it be the same 38.6 meters/sec A 10,000N car comes to a bridge during a storm and finds the bridge washed out. The 650-N
  66. physics

    I have another question for the problem below, so What is the speed of the car just before it lands safely on the other side? would it be the same 38.6 meters/sec A 10,000N car comes to a bridge during a storm and finds the bridge washed out. The 650-N
  67. physics

    I have another question for the problem below, so What is the speed of the car just before it lands safely on the other side? would it be the same 38.6 meters/sec A 10,000N car comes to a bridge during a storm and finds the bridge washed out. The 650-N
  68. More Physics

    The diagram below indicates three positions to which a woman travels. She starts at position A, travels 3.0 km to the west to point B, then 6.0 km to the north to point C. She then backtracks, and travels 2.0 km to the south to point D. a) What is the
  69. CHEM

    How do I work the following question? I found the amu of CaCO3=101.0872g/mol; 2HCL=72.92128g/mol; H2O=18.1582g/mol;CO2=44.0098g/mol; and, CaCl2=110.9834g/mol. You carefully weigh out 10.00g of powder and add it to 40.50g of solution. You notice bubbles as
  70. physics

    A hot air balloon decends toward the ground with a velocity of (2.0 m/s)yhat. A champagne bottle is opened to celebrate takeoff, expelling the cork horizontally with a velocity of (6.0 m/s)xhat relative to the balloon. When opened, the bottle is 6.2 m
  71. Temperature and Rate

    Q: The activation energy of a certain reaction is 32.9 kJ/mol At 25 degrees C the rate constant is 0.0160 units s-1 units. At what temperature in degrees Celsius would this reaction go twice as fast? My work: ln(0.0160/0.032) = (32.9 x 10-3/8.314)(1/T2 -
  72. chemistry

    Use the balanced equation below to answer the following questions. 2Al(NO3)3 + 3Na2CO3 Al2(CO3)3(s) + 6NaNO3 - What is the ratio of moles of Al(NO3)3 to moles Na2CO3? (1 point) - If 852.04 g Al(NO3)3 reacted with the 741.93 g Na2CO3, which would be the
  73. physics

    4. A mover wants to push a box down a hall. The mover applies an ‘action’ force on the box (the push). According to Newton’s 3rd law, there is a ‘reaction’ force applied in the opposite direction. The larger the action force applied by the mover,
  74. Science

    When 25.0 ml of a solution containing both Fe2+and Fe3 +ions is titrated with 23.0 ml of 0.0200M KMnO4(in dilute sulphuric acid), all the Fe2+ are oxidised to Fe3+ ions. Next, the solution is treated with Zinc metal to convert all the Fe3+ ions to Fe2+
  75. physics

    I have tried the ideal gas law to find the temp and Pressure so that i could then find the work but i am not getting the right answer in the end. any suggestions? 3.1 One kilogram of air in a piston-cylinder device undegoes a thermodynamic cycle composed
  76. molarity

    calculate the molarity of k+ in a soln prepared by adding .2L of .200M K3PO4 and 75.0mL of .5M K3PO4. assume volumes are additive. A few of steps here and more than one way to answer the problem You need to calculate the total number of moles of K3PO4 from
  77. chemisrty

    I have no idea how to do this activity..can someone please help!? In this activity you will investigate how chemical reactions are limited by the amount of reactants present. You will be using paper clips to represent atoms. You can describe the quantities
  78. Chemistry

    Back again with another problem :) How do you calculate the enthalpy change, in kJ/mol for the reaction of copper(II) sulfate? 0.0210 mol of copper sulfate was added to 25 cm3 of water. The temperature increased by 14°C. The specific heat capacity of
  79. Chemistry URGENT

    Could someone let me know if I have balanced these equations correctly. balanced equation of the reaction of iron and oxygen to produce iron(ii)oxide. 2Fe + O2 = 2FeO Also if the balanced equation of the reaction of iron and oxygen to produce
  80. algebra

    At the Wild Thing Zoo, you can rent a motorized cart to tour the grounds for a $4 initial charge and $4 per hour. An equation that represents the total cost y for x hours is y = 4 + 4x. At Safari Zoo, you can rent the same cart for a $3 initial charge and
  81. Chemistry. Please help!

    A 20.29 g sample of impure MgCO3 is completely decomposed at 1000oC in previously evacuated 2.0 L reaction vessel. After the reaction was complete the solid residue had a mass of 15.9 g. Assume that only MgCO3 could produce gas CO2 what percent of original
  82. Chemistry

    Suppose that 0.650 mol of methane, CH4(g), is reacted with 0.800 mol of fluorine, F2(g), forming CF4(g) and HF(g) as sole products. Assuming that the reaction occurs at constant pressure, how much heat is released? Substance & Enthalpy of Form. (kJ/mol)
  83. chemistry

    Write word equations for the following chemical reactions. a. Pure copper can be produced by heating copper(II) sulfide in the presence of diatomic oxygen from the air. Sulfur dioxide gas is also produced in this reaction. b. Water is formed by the
  84. PHYSICAL SCIENCE

    Imagine two billiard balls on a pool table. Ball A has a mass of 2 kilograms and ball B has a mass of 3 kilograms. The initial velocity of ball A is 9 meters per second to the right, and the initial velocity of the ball B is 6 meters per second to the
  85. chemistry

    N2(g) + 3 F2(g) → 2 NF3(g) ΔH° = –264 kJ/mol ΔS° = –278 J/(mol∙K) a. calculate the maximum amount of non-PΔV work that can be accomplished through this reaction at a temperature of 500°C. b. Determine the temperature at
  86. chemistry

    one reaction was between the aluminum and the leftover hydrochloric acid the products are aluminum chloride and hydrogen gas. the other reaction was the aluminum and the copper(II)chloride.. this produced aluminum chloride and copper metal. what was the
  87. Chemistry

    Which of the following is true about the reaction between sodium bromide and silver sulfate? 1. No reaction 2. Total ionic equation is identical to the net ionic equation 3. Sodium ions and sulfate ions are present in the toal ionic equation but not in the
  88. CHEMISTRY (HELP)

    Which of the following is true about the reaction between sodium bromide and silver sulfate? 1. No reaction 2. Total ionic equation is identical to the net ionic equation 3. Sodium ions and sulfate ions are present in the toal ionic equation but not in the
  89. chemistry

    For the gaseous equilibrium represented below, it is observed that greater amounts of PCl3 and Cl2 are produced as the temperature is increased. PCl5 (g) <==> PCl3 (g) + Cl2 (g) a) what is the sign of delta S for the reaction? Provide a legitimate
  90. Chem.

    Nitrogen oxide (NO) has been found to be a key component in the many biological processes. It also can react with oxygen to give the brown gas NO2. When one mole of NO reacts with oxygen, 57.0 kJ of heat is evolved. a) Write the thermochemical equation for
  91. Physics - URGENT

    A small block of mass 5 kg initially rests on a track at the bottom of a circular, vertical loop-the-loop, which has a radius of 0.8 m. The surface contact between the block and the loop is frictionless. A bullet of mass 0.7 kg strikes the block
  92. Chemistry

    a 40-year-old manger at a prominent legal firm in L.A experiences abdominal pain post lunch. He goes to the restroom a couple of times, but continues to experience pain and cramps. He evevtually decides to get himself examined. While questioning him, you
  93. Gen Chm II

    Determine the pressure-based Keq for the reaction: 2SO2(g) + O2(g)<--->2SO3(g) given that 1.00×10−2 moles of SO2 and 2.00×10−2 moles of O2 were initially placed in a 2.00 L reaction chamber. The chamber contained 7.5×10−3 moles
  94. chemistry

    hey guys please help me answer these questions. 1. can a strong acid be diluted. explain in detail 2. can a weak acid be diluted. explain in detail 3. how does your observation of sunlight change when you place two different concentrations of food colored
  95. physics

    A plane flying horizontally above Earth’s surface at 184 meters per second drops a crate. The crate strikes the ground 30.0 seconds later. What is the magnitude of the horizontal component of the crate’s velocity just before it strikes the ground?
  96. physics

    A building has become accidentally contaminated with radioactivity. THe longest lived material in the building is strontium-90 (atomic mass of 90 Sr 38 is 89.9077). If the building initially contained 5.0kg of this subtstance and the safe level is less
  97. chem

    The experiment described in the procedure was performed using a sample of Calcium with HCl(aq). The lab conditions were 25.00°C, and 747.0 torr barometric pressure. 112.7 mg of Calcium (MM: 40.08 g/mol) was reacted with 25.00 mL of 1.25M HCl(aq). 71.560g
  98. math

    Tank 1 initial contains 70 L (liters) of water and 450 g of salt, while tank 2 initially contains 20 L of water and 200 g of salt. Water containing 10 g/L of salt is poured into tank1 at a rate of 1 L/min while the mixture flowing into tank 2 contains a
  99. chemistry

    Thermite mixtures are used for certain types of weldings and the thermite reaction is highly exothermic. Given delta H= -852 KJ/mol, 1 mole of granular Fe2O3 and 2 moles of granular aluminum are mixed at room temperature and the reaction is initiated. the
  100. chemistry

    Thermite mixtures are used for certain types of weldings and the thermite reaction is highly exothermic. Given delta H= -852 KJ/mol, 1 mole of granular Fe2O3 and 2 moles of granular aluminum are mixed at room temperature and the reaction is initiated. the