1. Calculus - HELP URGENT PLEASE

    Consider a lake of constant volume 12200 km^3, which at time t contains an amount y(t) tons of pollutant evenly distributed throughout the lake with a concentration y(t)/12200 tons/km^3. assume that fresh water enters the lake at a rate of 67.1 km^3/yr,
  2. environmental engineering

    A lake receives 8 m3/s of inflow containing 0.3 mol/m3 of a chemical. The chemical reacts with a first order rate constant of 0.01 h-1. The outflow from the lake is also 8 m3/s. Assume there was no chemical in the lake at the beginning and volume of the
  3. science

    an you please solve the questions for me 1. 3 moles of pesticide of molecular mass 200 g/mole is applied to a closed system consisting of 20 m3 of water, 10 m3 of air, 1 m3 of sediment, and 0.001 m3 of fish. Determine the concentration and amount in both
  4. Chemistry

    320.0 gallons of 15 M nitric acid were added to a lake. The initial pH p the lake was 6.30 and the final pH was 4.60. What is the volume of the lake?
  5. chemistry

    600 gallons of 15 M nitric acid were added to a lake. The initial pH of the lake was 5.90 and the final pH was 3.70. What is the volume of the lake?
  6. Calculus 1

    A woman at a point A on the shore of a circular lake with radius r=4 wants to arrive at the point C diametrically opposite A on the other side of the lake in the shortest possible time. She can walk at the rate of 10mph and row a boat at 5mph. What is the
  7. Physics

    The temperature of 2.0 g of helium is increased at constant volume by ΔT. What mass of oxygen can have its temperature increased by the same amount at constant volume using the same amount of heat? I know for constant volume I should use the equation:
  8. Chemistry

    If the amount of gas is decreased and the temperature and pressure stay constant, what will be the effect on its volume? The volume will increase. The volume will decrease. The volume will remain the same. The volume will be reduced to zero.
  9. chemistry

    If the amount of mercury in a polluted lake is 0.40 ug/mL, what is the total mass of mercury in the lake? (The lake has a surface area of 100 mi squared and an average depth of 25 ft).
  10. CHEM

    If a 5.0L volume of O2 (g) is at 1.0 atm, if we hold the temperature and molar amount of O2 constant how many psi of pressure does this amount of O2 exert if the volume it is allowed to take up is decreased to 2.0L?
  11. Chem 104

    If a 5.0L volume of O2 (g) is at 1.0 atm, if we hold the temperature and molar amount of O2 constant how many psi of pressure does this amount of O2 exert if the volume it is allowed to take up is decreased to 2.0L?
  12. Chemistry

    If the amount of mercury in a polluted lake is 0.4 µg Hg/mL, what is the total mass in kilograms of mercury in the lake? (The lake has a surface area of 100mi^2 and an average depth of 20 ft.) I'll probably be able to solve this once I know what it's
  13. physics

    A rock is dropped from a tree of height 22 m into a lake (depth 4.0 m) below. After entering the water, the rock floats gently down through the water at a constant speed of 1.4 m/s to the bottom of the lake. What is the total elapsed time?
  14. Physics

    A rock is dropped from a tree of height 20 m into a lake (depth 4.6 m) below. After entering the water, the rock floats gently down through the water at a constant speed of 1.6 m/s to the bottom of the lake. What is the total elapsed time?
  15. Physics

    A swimmer has 8.20 x 10^-4 m^3 of air in his lungs when he dives into a lake. Assuming the pressure of the air is 95 percent of the external pressure at all times, what is the volume of the air at a depth of 10.0 m? Assume that the atmospheric pressure at
  16. Math CALCULUS HELP PLEASE

    Tidal volume is the volume of air displaced in the lungs between inhalation and exhalation (the amount of air in a breath). The residual volume is given by the amount remaining in the lungs even after the deepest exhalation (i.e. the minimum amount of air
  17. Chemistry

    Reactions in bomb calorimeters occurs at constant volume while the coffee cup calorimeter has reactions occurring at constant pressure. If one was to perform identical experiments in both of these instruments (one at constant volume and the other at
  18. Chemistry

    Concentration 15.8 mg/L Final Volume 100.0 mL What is the concentration of phosphate in the original lake water sample if the unknown lake water sample in the option has been diluted by taking 25.0 mL of lake water and diluting it to the indicated final
  19. Social Studies

    Lake Michigan and Lake Huron have the same surface elevation of ___ feet 577? The ___ Channel connects Lake Huron Lake St Clair and Lake Erie South? Niagara Falls is between Lake Erie and Lake __ Ontario? Lake Ontario is connected to the St Lawrence Seaway
  20. physics

    Lake Champlain, bordered by New York, Vermont, and Quebec, has a surface area of 1,126 km^2. If the energy (173 PJ) is provided by sunlight shining on the lake at an average rate of 200 W/m^2 but with only half that amount absorbed, how long will it take
  21. social studies

    what are the five great lakes You can find that at the site below: http://worldatlas.com/webimage/countrys/namerica/greatlk.htm they are lake superior lake michagan lake huron lake eria lake ontario
  22. environmental science

    Ecologists designed an experiment to determine if nitrates or phosphates are more limiting to algae growth. They divided a lake in Canada into two equal-sized sections by a vinyl curtain. Then they fertilized each sub-basin of the lake, one with nitrates
  23. Physics

    An air bubble of volume 15 cc is formed at a depth of 50 m in a lake. If the temperature of the bubble while rising remains constant then what will be the volume of the bubble at the surface?(Given: g=10 m/s2 & atm. pressure = 1.0 * 100000 Pa)
  24. chemistry

    Suppose 100 moles of a chemical is spilled into a lake. After 15.0 days, the total amount of the chemical in the lake 3.50 moles. Assuming that the reaction followed first order kinetics and no chemical was lost due to advection or volatilization, then
  25. Physics

    for every 10 m you descend below the surface of water, the pressure on you will increase by an amount equal to atmospheric pressure 101kpa. an air bubble in a lake has a volume of 20 mm^3 at a depth of 40m. predict what volume it will have just before
  26. Physics

    A primitive diving bell consists of a cylindrical tank with one end open and one end closed. The tank is lowered into a freshwater lake, open end downward. Water rises into the tank, compressing the trapped air, whose temperature remains constant during
  27. math

    Surfact of A lake is 31 feet above the surface of B lake. B lake is half as deep as A Lake and the bottum of the B lake is 8 feet below the bottom of A Lake. how deep is each lake?
  28. Physics

    An engineer decides to use a successful dam design for a new lake of the same depth. If the new lake has ten times the surface area as the lake held by the original dam, what, if any, design changes are necessary for the new dam to hold back the increased
  29. chemistry

    A gas bubble with a volume of 1.0 mL originates at the bottom of a lake where the pressure is 3.00 atm. Calculate its volume when the bubble reaches the surface of the lake where the pressure is 695 torr , assuming that the temp doesn't change. I got 0.003
  30. science grade 5

    how is heat related to temperature? Temperature tells us the DEGREE of heat; i.e., how hot is something. A temperature of 98.6 F is normal body temperature. A hot day is when the temperature is 95 degrees F. A cold day is when it is freezing outside. But
  31. chemistry

    One M&M candy has a volume of 1.0mL. What volume, in cubic meters, would one mole of M&M candies occupy? 2) For this next calculation, you’re going to compare the volume of a mole of M&Ms to Lake Erie, which has a volume of 116mi^3. How many lakes the
  32. math

    How much limestone (CaCO3) in kilograms would be required to completely neutralize a lake with a volume of 5.2 x 10^7 -L lake containing 5.0 x 10-3g of H2SO4 per liter?
  33. Math

    Having a lot of trouble with this one: Q) Tidal volume is the volume of air displaced in the lungs between inhalation and exhalation (the amount of air in a breath). The residual volume is given by the remaining in the lungs even after the deepest
  34. CALCULUS HELP NEEDED ASAP!

    Having a lot of trouble with this one: Q) Tidal volume is the volume of air displaced in the lungs between inhalation and exhalation (the amount of air in a breath). The residual volume is given by the remaining in the lungs even after the deepest
  35. chemistry

    How much limestone (CaCO3) in kilograms would be required to completely neutralize a lake with a volume of 5.2 x 10^9L . The lake contains 5.0 x 10^-3 moles of H2SO4 per liter?
  36. physics

    A primitive diving bell consists of a cylindrical tank with one end open and one end closed. The tank is lowered into a freshwater lake, open end downward. Water rises into the tank, compressing the trapped air, whose temperature remains constant during
  37. chemistry

    Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 0.4 mg Hg/mL, what is the total
  38. Math

    Several cows from a Caribou Herd took 4 days longer to travel 70km to Forde Lake, than it took them to travel 60km north beyond forde lake.They averaged 5km/h less before Forde lake because the foraging was better. What was their average speed for the part
  39. Chemistry

    Concentration 15.8 mg/L Final Volume 100.0 mL What is the concentration of phosphate in the original lake water sample if the unknown lake water sample in the option has been diluted by taking 25.0 mL of lake water and diluting it to the indicated final
  40. calc

    oil is leaking from a pipeline on the surface of a lake and forms an oil slick whose volume increases at a constant rate of 2000 cubic centimeters per minute. The oil slick takes the form of a right circular cylinder with both its radius r and height
  41. Algebra

    Bear Lake is 6 miles wide. The total time it took Jane to kayak back and forth across the lake was 2 hours. Her rate kayaking back was 3 times her rate going out across the lake. What was Jane's rate kayaking out across the lake?
  42. geography

    Will you please check my answers? 1. The largest lake in the world is located near the border of Asia and Europe. What is its name? Caspian Sea 2. What is the name of the country that shares the Iberian Peninsula with Spain? Portugal 3. Name the Great
  43. SS/WGeogrophy

    which lake does the equator pass through: Lake Victoria,Lake Malawi,or lake Chad?
  44. Physics Help!

    An air bubble has a volume of 1.51 cm3 when it is released by a submarine 102 m below the surface of a lake. What is the volume of the bubble when it reaches the surface? Assume that the temperature of the air in the bubble remains constant during ascent.
  45. PHYSICS

    An air bubble has a volume of 1.65 cm3 when it is released by a submarine 105 m below the surface of a lake. What is the volume of the bubble when it reaches the surface? Assume the temperature and the number of air molecules in the bubble remain constant
  46. Intro to Physics

    An air bubble has a volume of 1.65 cm3 when it is released by a submarine 105 m below the surface of a lake. What is the volume of the bubble when it reaches the surface? Assume the temperature and the number of air molecules in the bubble remain constant
  47. Physics HELP

    When the pressure P of a fixed mass of gas is inversely proportional to its volume V at constant temperature. (Where mass and temperature are constant) When volume is increased, the distance between the walls of the container is ?. This causes the average
  48. physics

    Assume all temperatures to be exact, and neglect significant figures for small changes in dimension. A diver releases an air bubble of volume 4.0cm3cm^3 from a depth of 16mm below the surface of a lake, where the temperature is 8.0∘C. What is the
  49. physics

    An airplane wants to drop a load of fish inot a small lake in the mountains. The plane is flying at its min speed 40 m/s, and is 50 meters above the surface of the lake. a.) Where relative to the lake should the plane be when the fish are dropped so that
  50. History8

    Which of the following most affects the size of the Great Salt Lake? A.the salt in the lake B. the region’s climate C. human modifications of the lake D. the minerals in the soil under the lake
  51. Social Studies

    Lake Huron is the northernmost Great Lake False? Lake Ontario is the closest Great lake to ottawa canada True?
  52. chemistry

    Oops I left a part of the question out: 2. Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes, leading to irreversible inactivity of these enzymes. If the amount of mercury in a
  53. math

    Does linear growth have to add the exact same amount, so a constant amount, each time or does it just have to be close?
  54. Math

    Charles's Law states that at constant pressure, the volume of a fixed amount of gas varies directly with its temperature measured in degrees Kelvin. A gas has a volume of 250 mL at 300 K. what is an equation for the relationship between volume and
  55. science

    Three equal-sized pans containing distilled (pure water),ocean water (3 percent salt),and water from the Great Salt Lake in Utah (about 20 percent salt)are placed in freezer. Which of the following would be the order in which these three liquids would
  56. Chemistry

    A geologist removes a sample of water from a lake in Nevada where the water level has been slowly dropping over time. The sample is found to be 0.02M in borax. The lake is circular in shape and is currently 500 meters in diameter and 50 meters deep. Using
  57. chemistry

    A small lake contains 0.0500 mi3 of water [H2O]. If the density of water is 1.000 g/mL, determine the volume (in gal) of water in the lake.
  58. chemistry

    If the volume is 226 L at 1.7 atm, find the volume at 2.8 atm. Assume the temperature and amount of gas remain constant. Answer in units of L.
  59. Chemistry

    Heat Capacity at constant volume: CV = (partial q / partial T) with V constant since volume is constant, work is zero and dq = dU, so CV = (partial U / partial T) with V constant Delta U = CV * Delta T Does this final relationship hold during a reaction
  60. Calculus

    A woman at point A on the shore of a circular lake with radius 2.5mi wants to arrive at the point C diametrically opposite A on the other side of the lake in the shortest possible time. She can walk at a rate of 3.25 mi/hr and row at a rate of 2 mi/hr.
  61. Physics

    Calculate the gravitational potential energy of the water in a lake of volume 100km^3 (mass=1.0x10^14kg). The lake has an average height of 50m above the hydroelectric generators at the base of the dam holding the water back.
  62. physics

    An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at +40 ft/s2. After some time t1, the rocket engine is shut down and the sled moves with constant velocity v for a time t2. If the total distance traveled by the
  63. Chemistry

    C2H5NO2 + 2H2O → 2CO2 + NH3 + 3H2 You begin with 1.25 × 10-2 moles of glycine and an excess amount of water that will allow the reaction to proceed completely to products. This is all in a vessel with a volume of 850 mls at 27°C. Assume that the
  64. Science

    I have 8 questions and 1 question in the end that I don't need help with. Identify possible variables in the following situations. What variables can affect the sprouting of a bean seed? I think (I didn't answer yet so I'll just go with what I think oh and
  65. Science

    A motor boat starting from rest on a lake accelerate in a straight line at a constant rate of 3m/s for 8s. How far does the boat travel during the time?
  66. science.

    In powder mills park there is a lake called a kettle lake. describe how this lake was formed.
  67. math

    a company want to lay cable across a lake. to find the lengh of the lake, they madethe measurements 180ft and 150ft. what is the length of the lake?
  68. Math

    The number f water hyacinth plants growing on a lake increases exponentially with time. On Tuesday the number of plants is 150. That Friday the number has risen to 240. If it takes 3400 plants to completely cover the lake, will the lake be completely
  69. Algebra

    the clarke family went sailing on a lake. Their boat averaged 6 km per hour. the Rourke family took their outboard runabout for a trip on the lake for the same amount of time. Their boat averaged 14 km per hour. The Rourke family traveled 20 km farther
  70. calculus

    Carbon-14 is a radioactive substance produced in the Earth's atmosphere and then absorbed by plants and animals on the surface of the earth. It has a half-life (the time it takes for half the amount of a sample to decay) of approximately 5730 years. Using
  71. chemistry

    2.) If the volume of a gas at -73 degrees celcius is doubled while pressure is held constant, what will be its final temperature in degrees celsius? 5.) A gas storage tank at a large industrial plant is designed to provide fuel under constant pressure.
  72. Maths

    A swimming pool is being emptied and the amount of water remaining in the pool after t minutes after emoting commences is given by: Time t (min) Volume V (L) 0 30000 20 28800 40 25200 60 19200 80 10800 Find the equation describing the volume of water
  73. Physics

    An RC-circuit has a time constant of 6x10-3 seconds. The capacitor stores a maximum energy of 8 J, when charged using a 3-Volt battery. Using the same battery, we want to increase tenfold the amount of stored energy, while keeping the same time constant
  74. physics

    Lake Erie contains roughly 4.00 1011 m3 of water. (a) How much energy is required to raise the temperature of that volume of water from 9.0°C to 12.0°C? (b) How many years would it take to supply this amount of energy by using the 850-MW exhaust energy
  75. PHYSICS

    Lake Erie contains roughly 4.00 1011 m3 of water. (a) How much energy is required to raise the temperature of that volume of water from 9.0°C to 11.0°C? J (b) How many years would it take to supply this amount of energy by using the 1250-MW exhaust
  76. SCience

    An RC-circuit has a time constant of 6x10-3 seconds. The capacitor stores a maximum energy of 8 J, when charged using a 3-Volt battery. Using the same battery, we want to increase tenfold the amount of stored energy, while keeping the same time constant
  77. science help pls pls

    Look at the position of Location 1, Location 2, and Location 3 in this picture. Simple diagram of a lake represented by a wavy circle. The circle is labeled 'Lake,' and there are three points outside of the lake: 'Location 1' is to the northeast of the
  78. chem

    A sample of gas has a volume of 50 mL and an initial temperature of 380 K. The temperature must be changed to _____ K in order to halve the volume. Assume constant pressure and amount for the gas.
  79. Physics

    Lake Erie contains about 4.8 x 10^17 grams of fresh water. Assume that the lake has frozen solid and that the ice starts off at -3 C. How much energy would the lake need to absorb from the Sun to cause it to evaporate completely?
  80. physics

    Lake Erie contains roughly 4.00 multiplied by 1011 m3 of water. (a) How much energy is required to raise the temperature of that volume of water from 11.0°C to 13.0°C? J (b) How many years would it take to supply this amount of energy by using the 950-MW
  81. Alegabra

    Russell Gossman is training for the Olympics. He wants to know the distance across Lake Royal, so he can write in his training logbook how far he rows each day. If from one point on the shore to one side of the lake is 13 km and from the same point to
  82. Math

    Several cows from a Caribou Herd took 4 days longer to travel 70km to Forde Lake, than it took them to travel 60km north beyond forde lake.They averaged 5km/h less before Forde lake because the foraging was better. What was their average speed for the part
  83. Math

    1. Cate went on a trip of 120 miles at x miles per hour. Returned over same route at 5miles/hour faster than previous rate.If time for return trip was one-third of an hour less than time for the outgoing trip,how do you find x? (Set up the chart right, and
  84. Math

    I need to write the specified ratin as a simplified fraction. A certai lake is 1100 ft deep. A nearby lake is 300 feet deep. Write the ratio of te fist lake's depth to the second lake's depth.
  85. Math

    Take the greatest care with your significant digits. If you don't this qusestion is not do able. Llyn Gweision ( A welsh lake) has a surface area of 10km2. It is fed by two rivers: the afron Chwefru and the nant aeron. The Chwefru has a catchment area of
  86. Biomechanics

    If the volume of a material is conserved under loading (Volume without force = Volume with force) what is the material’s Poisson’s ratio? You can assume that the material is isotropic (it will behave the same in every direction). Hint: take a cube and
  87. math

    East Battle Lake in Minnesota covers an area of about 1950 acres or 8.5X10^7 square feet and its average depth is about 3.2x10^1 feet. a. Estimate the cubic feet of water in the lake. (hint: Volume=area x average depth.) b. One cubic foot of water equals
  88. calculus

    3. The radius r of a sphere is increasing at a constant rate of 0.04 centimeters per second. (Note: The volume of a sphere with radius r is v=4/3pir^3 ). a. At the time when the radius of the sphere is 10 cm, what is the rate of increase of its volume? b.
  89. Algebra

    Members of the Lake Shawnee club pay $40 per summer season plus $7.50 each time they rent a boat. Nonmembers pay $12.50 each time they rent a boat. How many times would both a member and a nonmember have to rent a boat in order to pay the same amount?
  90. science (physic)

    An expansible ballon filled with air floats on the surface of a lake with 2/3 of its volume submerged .How deep must it be sunk in the water so that it is just inequilibrium neither sinking further nor rising? It is assumed that the temperature of the
  91. Math :)

    Since the purpose of an ice cube is to keep a drink cold, is it better for an ice cube to have a high volume or a low volume? I thought that the higher the volume, the longer the amount of time the ice cube does NOT melt. Which one is best? Thank you. :)
  92. physics

    two canoeists start paddling at the same time and head toward a small island in a lake. caneist 1 paddles with a speed of 1.35 m/s at an angle of 45 degrees north of east. canoeist 2 starts on the opposite shore of the lake,a distance of 1.5 km due east of
  93. Physics

    At a height of 15 meters above the surface of a lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.150 s later. The air and water temperatures are 20°C. How deep is the lake?
  94. chemistry

    Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes, leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 215 ng of mercury / mL, what is
  95. Physics

    Remember the Poynting vector? The magnitude of this vector gives the amount of energy per second that flows through a unit area (in the direction it gives) because of the presence of a combination of electric and magnetic field, like in an electro-magnetic
  96. MATH/SCIENCE

    Llyn y Gweision (a Welsh lake) has a surface area of 10 km2. It is fed by two rivers: the Afon Chwefru and the Nant Aeron. The Chwefru(Ich) has a catchment area of 1250 km2. The Aeron(Iae) has a catchment area of 2.400 * 106 ha. The outflow stream, the
  97. Environmental science

    Llyn y Gweision (a Welsh lake) has a surface area of 10 km2. It is fed by two rivers: the Afon Chwefru and the Nant Aeron. The Chwefru(Ich) has a catchment area of 1250 km2. The Aeron(Iae) has a catchment area of 2.400 * 106 ha. The outflow stream, the
  98. General Chemistry : for Nursing

    Im Having a really Hard time with this problem :( ---> A sample containing 5.60g O2 gas has a volume of 31.0L . Pressure and temperature remain constant. 1 .) Oxygen is released until the volume is 8.00L . How many moles of O2 are removed?
  99. AP Physics

    At a height of 5 meters above the surface of a freshwater lake, a sound pulse is generated. The echo from the bottom of the lake returns to the point of origin 0.140 s later. The air and water temperatures are 20°C. How deep is the lake?
  100. Physics

    A hollow plastic sphere is held below the surface of a freshwater lake by a cord anchored to the bottom of the lake. The sphere has a volume of 0.600m^3 and the tension in the cord is 840N . What is the mass of the sphere? And Calculate the buoyant force