1. physics

    An aircraft gains speed during takeoff due to the constant thrust of its engine. When is the acceleration during takeoff greatest-at the beginning of the run along the runway or just before the aircraft lifts into the air? why?
  2. Physics

    An ideal gas heat engine operates in a Carnot Cycle between temperatures of 266 and 115°C. It absorbs 4250 cal per cycle at 266°C. What is its efficiency as a percentage
  3. Math

    What is the exact value of sin 5ð and how do you find it? type in the google search engine.. sin(5degrees) It will compute it for you. It appears you pasted something that the ASCII didn't translate. You'll need to type out the value for the angle.
  4. chemistry

    The density of diamond is 3.51g/cm^3,and the density of platinum is 21.43g/cm^3.If equal masses of diamond and platinum are transferred to equal volumes of water in separate graduated cylinders,which graduated cylinder would have the greatest volume
  5. chemistry

    The average swimming pool has a volume of about 28,000 gallons. Suppose a swimming pool was filled with pH 7.00 water. However, you need to adjust the pH to 4.75. How much acid pool acid (which is 1.00 M HCl) do you need to add to the pool? The units are
  6. Biology

    Oxidized (blue) DPIP becomes colorless when it is reduced – that is, when it receives electrons. A diagram of the photosynthetic light reaction shows that water molecules are the source of these electrons. How is it that the DPIP was only able to receive
  7. BIOLOGY( please help me)

    Oxidized (blue) DPIP becomes colorless when it is reduced – that is, when it receives electrons. A diagram of the photosynthetic light reaction shows that water molecules are the source of these electrons. How is it that the DPIP was only able to receive
  8. integrated physics and chem

    Element A and element B have bonded and formed compound AB. Which of the following statements is true? A. Compound AB has chemical and physical properties that are completely different from those of A and B. B. Compound AB has chemical and physical
  9. Physics

    On the question that someone posted.....I asked my teacher on what formula I should use and said I should use this one: V^2= Vo^2+2ax (V^2 is the velocit, Vo is the initial velocity, a is accerlation and x distance . An automobile is traveling at 30 km/hr.
  10. Physics

    An automobile having a mass of 1220 kg is driven into a brick wall in a safety test. The bumper behaves like a spring of constant 2.42 × 106 N/m and compresses 2.99 cm as the car is brought to rest. What was the speed of the car before im- pact, assuming
  11. science

    jay heated 120mL of water that was 20 degrees celsius to 80 degrees celsius. a)how much did the temperature of water change? b) how much heat did jay add to the water? c) if jay used a liquid that was not water, the specific heat would not equal:(circle
  12. 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
  13. Mathematics

    15 liters of water is poured from container A to Container B and 10 liters of water is poured from container A to container C. If C had 20 liters of water less than A, how many more liters of water does C have than A? A. 10L C. 20L B. 15L D. 25L What
  14. Chemistry

    A)Whats the pH of Distilled water.(is it really 7 or can be 6). B)Also whats the pH of (4o ml DI water +1.0 ml of 6.0 M HCl)? C)and also pH of (4o ml DI water +1.0 ml of 6.0 M NaOH)?
  15. Nutrition

    What is the difference between drinking water and distilled water? Can we make our own distilled water?
  16. physics

    Using the inverse-square gravitational law, calculate the work required to lift a 1000-kg satellite from the earth's surface to an altitude of 100 mi and inject it into orbit at 17,500 mph. How long would a 300-hp engine have to be run to produce this much
  17. Chem

    Three bulbs are connected by tubing, and the tubing is evacuated. The volume of the tubing is 32.0 mL. The first bulb has a volume of 78.0 mL and contains 2.72 atm of argon, the second bulb has a volume of 250 mL and contains 2.83 atm of neon, and the
  18. General chem lab

    This involves Enthalpy of Neutralization: A student determined the calorimeter constant of the calorimeter. Using a plotted line. The student added 50ml of cold water to 50 ml of heated water in a Styrofoam cup. The initial temperature of the cold water
  19. Physics

    A diver springs upward from a board that is three meters above the water. At the instant she contacts the water her speed is 8.80 m/s and her body makes an angle of 76.0° with respect to the horizontal surface of the water. Determine her initial velocity,
  20. physics

    A 62.7-kg person jumps from rest off a 2.98-m-high tower straight down into the water. Neglect air resistance. She comes to rest 1.09 m under the surface of the water. Determine the magnitude of the average force that the water exerts on the diver. This
  21. Science

    What percent of water is not easily accessible or usable on earth? *A. .6% B. 12.5% C. 50% D. 99% Subtract the answer from the last question from 100%. What does the remainder represent and what are the sources of this percentage of water? A. 97% rivers
  22. Chemistry 12

    The molar heat of vaporization of water is 42 kJ/mol. How much energy is released by the condensation of 3.0 g of water? So for water there will just be one mol. I think this is how you do it, but it doesn't match the answer in the worksheet. q=mc delta t
  23. calculus

    A trough is 15 ft long and its ends have the shape of isosceles triangles that are 4 ft across at the top and have a height of 1 ft. If the trough is being filled with water at a rate of 14 ft^3/min, how fast is the water level rising when the water is 8
  24. College Chemistry

    A 86.3mL sample of water is initially at 17.4 degC. How many kilojoules (kJ) of heat must be added to raise the temperature of the water to 31.8? The specific heat capacity of water is 4.184 J/g.degC. How do I set this up to find the answer. Really
  25. Physics

    A 500 g sample of gold heated to 971.0 deg. C is placed in a calorimeter containing 220 g of water initially at 20.0 deg. C. If no heat is lost to the surrounding environment what will the final temperature of the water be? [HINT: At the end, the sample
  26. calculus

    A tank of water has a base a circle of radius 2 meters and vertical sides. If water leaves the tank at a rate of 6 liters per minute, how fast is the water level falling in centimeters per hour? [1 liter is 1000 cubic centimeters]
  27. Science

    Describe the method you would use to separate eachg mixture. Methods: Picking apart, filtering, using density, using magnetism, dissolving, evaporating. a)sand and water b)oil and water c salt and pepper d)sand and pebbles e)sugar and water 2. List several
  28. physics

    Explain in a few words why, when operating a garden hose fitted with a trigger-operated nozzle, the water jet is momentarily more powerful at the instant the trigger is squeezed than later, when there is a continuous stream of water. Show that the amount
  29. Science

    Your family is going to have a contractor build a pool in your backyard. Your mom wants to make this a learning experience, so she asks you to find the mass of the water that will fill the pool. She has told you that the pool holds 75,700 L of water, and
  30. grammar check? idk

    does this make sense? Fertilizers are combinations of nutrients that plants need to grow. The primary nutrients of fertilizers are three different elements which are nitrogen, phosphorus, and potassium. These elements are often combined into a NPK blend.
  31. Math(Help, AssignmentDueToday)

    Adora has a photo of the Calgary tower that measures 7cm by 19cm. She scans the photo and enlarges it by 160%. By what percentage will the area of the photo increase? A.) 160% B.) 320% C.) 410% D.) 256% A shop sells a small globe that hangs on a keychain,
  32. Chemistry lab

    A 1.340gram sample of an unknown acid, H3A, was placed in a 250.0 mL volumetric flask and diluted to volume with water. A 45.35 mL sample of this acid solution was titrated with 37.77 mL of a 0.1006M NaOH solution. A) Using one set - up dimensional
  33. Chem

    The fizz produced when an alka-seltzer tablet is dissolved in water is due to the reaction between sodium bicarbonate and citric acid: 3NaHCO3 + H3C6H5O7 -> 3CO2 + 3H2O + Na3C6H5O7 In an Experiment 1.00 g of sodium bicarbonate and 1.00g of citric acid
  34. 11th grade

    A sample consisting of 22.7 g of a nongaseous, unstable compound X is placed inside a metal cylinder with a radius of 8.0 cm, and a piston is carefully placed on the surface of the compound so that, for all practical purposes, the distance between the
  35. Chemistry

    A sample consisting of 22.7 g of a nongaseous, unstable compound X is placed inside a metal cylinder with a radius of 8.0 cm, and a piston is carefully placed on the surface of the compound so that, for all practical purposes, the distance between the
  36. physics

    A 710 kg car drives at a constant speed of 23m/s . It is subject to a drag force of 500 N. What power is required from the car's engine to drive the car (a) on level ground? (b) up a hill with a slope of 2.0?
  37. heat

    the main purpose of the turbine in the turbojet engine is to? The turbine rotates the compressor, compressing the inlet air. Often, electrical generators and hydraulic pumps are attached to the turbine via gears also. drive the compresser
  38. Statistics

    In advance of the 1936 Presidential Elections, a magazine titled Literary Digest released the results of an opinion poll predicting that the republican candidate Alf Landon would win by a large margin. The magazine send post cards to approximately
  39. physics

    The speed of an automobile increases from 11 m/s to a speed of 47 m/s over a time period of 9.0 seconds. What is the average rate at which the speed of this car is changing during this time period?
  40. math

    a certain automobile gas tank contains15 gallons 12% which is ethanol how much gasoline should be removed so that when replaced with pure ethanol there is 22% ethanol in gas tank?
  41. Physics

    A 1.4 kg ball is thrown upwards off the side of a building with a spped of 5.8 m/s and falls into an ocean 16 meters below. Once the ball hits the water it travels a depth of 1.4m then floats to the surface. Assuming the acceleration of the ball when it
  42. chemistry

    The density of diamond is 3.51 g/cm^3 and the density of platinum is 21.43g/cm^3. If equal masses of diamond and platinum are transferred to equal volumes of water in separate graduated cylinders, which graduated cylinder would have the greatest volume
  43. PHYSICS

    Fish achieve neutral buoyancy (so they don't have to swim constantly to stay in place) via a swim bladder. A swim bladder is a little internal sack that they can inflate/deflate with air, which changes their volume but not their total mass. To see how this
  44. Chemistry PLS HELP!!!

    A student collects oxygen gas by water displacement at a temperature of 17 Celsius. A barometer reads 92.3 kPa. What is the pressure of the water vapor? Look it up on a water vapor pressure chart. What is the pressure of the oxygen gas? (Answer: ~14.0 mmHg
  45. ashford university

    1. Which water cycle processes are represented in this model and by what components? Answer = 2. Which water cycle processes are not represented? How could the model be altered to include each of these processes? Answer = 3. How would the “weather” be
  46. chem

    what happens when NaCl(s) is dissolved in water? (1)Cl-ions are attracted to the oxygen atoms of the water (2)Cl-ions are attracted to the hydrogen atoms of the water. (3)Na+ions are attracted to the hydrogen atoms of the water. (4)no attractions are
  47. Chemistry

    Sea water conducts electricity. Which statements give the best explanation for this a) Ions are able to move around in sea water b) Electrons can pass from ion to ion in the sea water c) The sea water contains more ions with positve charges than ions with
  48. chemistry

    In a constant-pressure calorimeter, 60.0 mL of 0.930 M H2SO4 was added to 60.0 mL of 0.320 M NaOH. The reaction caused the temperature of the solution to rise from 22.68 °C to 24.86 °C. If the solution has the same density and specific heat as water
  49. chemistry

    When a 28.8mL of .500M H2SO4 is added to 28.8mL of 1.00M KOH in a coffee-cup calorimeter at 23.50 degrees Celsius, the temperature rises to 30.17 degrees Celsius. Calculate the ^H(change in enthalpy)of this reaction. (assume total volume is the sum of
  50. PHYSICS

    A tuning fork is set into vibration above a vertical open tube filled with water. The water level is allowed to drop slowly. As it does so, the air in the tube above the water level is heard to resonate with the tuning fork when the distance from the tube
  51. physics

    A tuning fork is set into vibration above a vertical open tube filled with water. The water level is allowed to drop slowly. As it does so, the air in the tube above the water level is heard to resonate with the tuning fork when the distance from the tube
  52. math questions

    WORD PROBLEM: Tims tet grades in french were: 86,96,88,91 what score must Tim make on his next test to average 92? a 89 b 93 c 97 d 99 I said 99. because when you add all numbers its 460/5 = 92 2) the water level indicator measures the rise and fall in
  53. Chemistry

    Suppose that 100.0 g of ice a 0 degreesC are added to 300.0 g of water at 25.0 degrees . Is this sufficient ice to lower the temperature of water to 5.00 degrees C and still have ice remaining? Calculate the energy (heat) which must be removed from water
  54. chem11

    Suppose you have a large supply of sponge balls with weights in the centre, so that when the balls are piled on each other the bottom ones are flattened. Sketch a graph that generally describes mass vs. volume for these sponge balls. Also, would weighted
  55. Physics multiple choice questions

    1. Which of the following energy transformations best describes the operation of a solar powered battery charger? (a) electrical energy --> thermal energy --> kinetic energy (b) nuclear energy --> potential energy --> chemical energy (c)
  56. Physics multiple choice questions

    1. Which of the following energy transformations best describes the operation of a solar powered battery charger? (a) electrical energy --> thermal energy --> kinetic energy (b) nuclear energy --> potential energy --> chemical energy (c)
  57. Math

    the formula for the volume of a cone is v=1/3pir^2h. The volume cone x is 2 times the volume of cone Y. Why the height of cone X is 2 times the heigh of the cone Y, and the radius of cone X is the same as the radius of cone Y.
  58. Chemistry - Density

    Automobile batteries contain sulfuric acid. Calculate the number of grams of sulfuric acid in 0.500L of battery acid if the solution has a density of 1.28g/mL and is 38% H2SO4 (small numbers) by mass? Can you please answer this for me? double post.
  59. algebra

    The volume of a gas varies directly with its temperature and inversely with the pressure. If the volume of a certain gas is 20 cubic feet at a temperature of 350K and a pressure of 35 pounds per square inch, what is the volume of the same gas at 330 K when
  60. chemistry

    a 42 piece of ice at 0.0 C is added to a sample of water at 8.0 C. all of the ice melts and the temperature of the water decreases to 0.0 C. how many grams of water were in the sample.
  61. desity

    A fish tank holds 35 {\rm gal} of water. Using the density of 1.0 {\rm g/mL} for water, determine the number of pounds of water in the fish tank
  62. Chemistry

    A 70 piece of ice at 0 is added to a sample of water at 6. All of the ice melts and the temperature of the water decreases to 0. How many grams of water were in the sample?
  63. physics

    A sonar signal of frequency 1.00 106 Hz has a wavelength of 1.40 mm in water. (a) What is the speed of the signal in water? (b) What is its period in water? (c) What is its period in air?
  64. English

    1. I will drink enough water. 2. I will dring water enough. 3. I will eat enough water. ---------------------------------- Are #1 and #2 correct grammatically? What about #3? Can we use 'eat' instead of 'drink'? In a basic grammar test, can we use both #2
  65. physics

    A sonar signal of frequency 1.00 106 Hz has a wavelength of 1.40 mm in water. (a) What is the speed of the signal in water? (b) What is its period in water? (c) What is its period in air?
  66. Chemistry

    A 50.0- piece of ice at 0.0 is added to a sample of water at 8.0. All of the ice melts and the temperature of the water decreases to 0.0. How many kilograms of water were in the sample?
  67. Chemistry

    If the solubility of arsenic trioxide in water at 25 C is 20g/1L water, would 250mL of water at 25 C containing 3.5g of arsenic trioxide be saturated, unsaturated, or supersaturated?
  68. Algebra 1

    Thank you in advance for your kind help! How much fresh water should be mixed to a 30% salt water solution, to obtain 90 gallons of a 23% salt water solution?
  69. math!!!!!!! help 3

    a water cooler contains 5 gallons of water.if drink 3/5 gallon for each of the next 6 days how many gallons will be left in water cooler at the end of the sixth?
  70. Algebra 1

    Thank you in advance for your kind help! How much fresh water should be mixed to a 30% salt water solution, to obtain 90 gallons of a 23% salt water solution?
  71. physics

    6) A sub has a volume of 20 m3 and a density of 1500 kg/m3. It sinks to a depth of 40 meters. The density of sea water is 1025 kg/m3. a. What is the pressure on the sub at this depth? b. The sub has a window with a diameter of 30 cm. What is the net force
  72. MATH: PROBABILITIES

    You ask a neighbor to water a sickly plant while you are on vacation. Without water the plant will die with probability 0.85. With water it will die with probability 0.55. You are 89 % certain the neighbor will remember to water the plant. You come back
  73. MATH: PROBABILITIES

    You ask a neighbor to water a sickly plant while you are on vacation. Without water the plant will die with probability 0.85. With water it will die with probability 0.55. You are 89 % certain the neighbor will remember to water the plant. You come back
  74. science

    When substances such as sugar and table salt are dissolved in water, the freezing points of the new solutions are lower than the freezing point of water. Also, the more material dissolved, the lower the freezing point. The boiling points of these
  75. Physics

    A sound wave travels in air toward the surface of a freshwater lake and enters into the water. The frequency of the sound does not change when the sound enters the water. The wavelength of the sound is 3.52 m in the air, and the temperature of both the air
  76. science

    About a month ago I asked you a question and it was, A quantity of gas has a volume of 0.20 cubic meter and an absolute temperature of 333 degrees Kelvin. When the temperature of the gas is raised to 533 degrees Kelvin, what is the new volume of the gas?
  77. physics

    Hi, could anyone help me please, Thank. Gas in a container is at a pressure of 1.3 atm and a volume of 1.0 m3. (a) What is the work done on the gas if it expands at constant pressure to twice its initial volume? (b) What is the work done on the gas if it
  78. physics

    Hi!could anyone help me please, Thank. Gas in a container is at a pressure of 1.3 atm and a volume of 1.0 m3. (a) What is the work done on the gas if it expands at constant pressure to twice its initial volume? (b) What is the work done on the gas if it is
  79. Chemistry

    Hi there. I'm doing a paper on Biology (yes I know, will explain the chem link in a sec) and in it am trying to find the best pH level for Slaters, using limewater and filtered water to change concentrations. I have done experiments and using bunch of
  80. algebra

    When fighting a fire the velocity V of water being pumped into the air is modeled by the function v=√2hg, where h represents the maximum height of the water and g represents the acceleration due to gravity (32 ft/s^2) The Jackson Fire dept must
  81. Math

    A rectangular prism is completely packed with 180 cubes of edge length fraction 1 over 3 inch, without any gap or overlap. Which of the following describes the volume of this rectangular prism? 19 unit cubes and 9 smaller cubes of volume fraction 1 over 27
  82. Physics Help Please!!!! Urgent!!

    In an experiment, a boar (2600 kg) slows down from 11 m/s to 8 m/s in 5 sec when the engine is stopped. a) Determine the drag force. b) Using this information, what is a good approximation of the forward thrust force needed to keep the boat cruising at a
  83. Science (Physics)

    A motorist driving a 1200-kg car on level ground accelerates from 20.0 m/s to 30.0 m/s in a time of 5.0s. Neglecting friction and air resistance, determine the average mechanical power in watts the engine must supply during this time interval.
  84. Science

    A Herculean bomber jet accepts 40kg of air per second at a velocity of 200m/s, burns 2kg of fuel at the same time,and releases exhaust gases at 600m/s relative to the bomber. find the thrust due to its engine.
  85. psy202

    which of the following do experts recommend regarding the search for information on the internet avoid boolean operators since new technology has made them obsolete stick to one search engine like google so that bookmarks are better organized bookmark any
  86. physics- energy and work

    A 47.6-kg diver steps off a 10.82 m high diving board and drops straight down into the water. If the diver comes to rest 5.3 m below the surface of the water, determine the average resistance force exerted on the diver by the water. What is the total
  87. FST

    A tsunamiis a fast-moving ocean wave caused by an underwater earthquake. The water first goes down from its normal level, then rises an equal distance above its normal level, and finally returns to its normal level. The period is about 15 minutes. Suppose
  88. Chemistry

    A 35g sample of Fe is dropped into 80g of water at 20 degrees Celsius. What is the final (equilibrium) temperature of the iron/water? This isn't really a chemistry problem. There will be no chemical reaction. It is a heat capacity (physics) problem. Use
  89. Science

    A student puts different types of soil into 2 pots and pours the same amount of water into the pots. How can she find out how much water stays in each type of soil? A By weighin each pot B By looking at the pot C Measuring amount of water that drained from
  90. chemistry

    Got my as chemistry practical next week on OCR. Really stuck on it, don't know how to work out how the expected volume of CO2 is greater than that is obtained. Looked at the mark scheme ocr chemistry evalutative task specimen , but its not much help as it
  91. Exploring Space

    if u could travel at the speed of ligt without fuel, where would the energy required for the engine come from? is this possible? it is impossible to travel anywhere without fuel. The only other option is to walk by foot. I don't know the answer to the
  92. Physics

    You drive your car from home at an average spped of 78km/h for 2 h. Halfway to your destination, you develop some engine problems, and for 4 h you nurse the car the rest of the way. What is your average velocity for the entire trip?
  93. math

    A diesel engine's piston compresses 16 cm3 of fuel-air mixture into 1 cm3. The pressure changes from 1 atmosphere to 48 atmospheres. If the initial temperature of the gas was 305 K, what was the final temperature?
  94. Algebra

    On a journey of 600 km, a train was delayed 1 hour and 30 min after having covered 1/4 of the way. To arrive on time at the destination, the engine driver had to increase the speed by 15 km/hour. How long did the train travel for?
  95. chemistry

    A diesel engine's piston compresses 16 cm3 of fuel-air mixture into 1 cm3. The pressure changes from 1 atmosphere to 48 atmospheres. If the initial temperature of the gas was 305 K, what was the final temperature?
  96. physics

    A car engine has 90 kW and an efficiency of 12 percent. Let's assume a simple model of air friction, Fair=Kv2 , with K=027kgm for this car. If there is no other friction, and no winds, what is the maximum speed it can reach?
  97. Grade 6: money and measures

    An empty rectangular tank with a base are of 2400 cm2 is filled with water from two taps.one tap can fill the tank with 12 liters of waTer per minute while the other tap can do it at 3 liters per minute. a. what will be the depth of water in the tank after
  98. Chemistry

    The density of diamond is 3.51g/cm^3,and the density of platinum is 21.43g/cm^3.If equal masses of diamond and platinum are transferred to equal volumes of water in separate graduated cylinders,which graduated cylinder would have the greatest volume
  99. physics

    water is flowing at 3 m/s in a horizontal pipe under a pressure of 200 kpa. the pipe, which narrows to half its original diameter, is laid out on a level ground? a) what is the speed of flow in the narrow section? b) what is the pressure in the narrow
  100. chemistry

    water is flowing at 3 m/s in a horizontal pipe under a pressure of 200 kpa. the pipe, which narrows to half its original diameter, is laid out on a level ground? a) what is the speed of flow in the narrow section? b) what is the pressure in the narrow