1. Physics - Aristotle and his theory

    Aristotle beleived that wood was a combination of fire, water, and earth. Use his 4 element theory to explain why a wooden boat floats on water. His theory is hard for me to understand. The only thing I know is that the boat floats on the water because the
  2. Physics

    (a) Calculate the kinetic energy that the earth has because of its rotation about its own axis. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States in one year
  3. math

    The Position of two A and B on the earth’s surface are (36°N, 49°E) and (360°N, 131°W ) respectively. (a) The difference in long between town A and town (b) Given that the radius of the earth is 6370, calculate the distance town A and town B. (c)
  4. Math

    The Position of two A and B on the earth’s surface are (36°N, 49°E) and (36°N, 131°W ) respectively. (a) The difference in long between town A and town B (2 marks) (b)) Given that the radius of the earth is 6370, calculate the distance town A and
  5. physics

    a)The star ships Enterprise and Potemkin leave the Earth and travel in opposite directions each at 0.60c relative to an observer on Earth.In the Enterprise's frame of reference how fast is the Potemkin moving away? b) Through what voltage must you
  6. Astronomy

    You've been told the Earth puts out 0.070 [W/m squared] as a global average. What would you predict would be the surface heat flux in [W/m squared] from a planet that is 70% larger in radius than the Earth, but has the same bulk composition. You can assume
  7. Physics ( using earth to find pressure of planet y

    3. A model of Earth’s interior: Look up the radius and mass of the Earth. Radius is 6,371 km Mass is 5.974 x 10^24 kg Calculate its average density. p_e = (5.974 x 10^24 kg)/ (4/3)pi r^3 = (5.974 x 10^24 kg)/ (4/3)pi (6371)^3 = 5.54 g/cm^3 Imagine a
  8. help

    In “who knows if the moon’s,” the speaker imagines traveling somewhere. Where does he imagine traveling? to Earth from the moon to a nearby garden to the moon from Earth to a city in the sky thx
  9. science

    Darren the astronaut traveled to Planet U-427, a planet that is as big as Earth but is half the mass of Earth. What can you say about Darren's weight in this planet?
  10. Science

    Darren the astronaut traveled to Planet U-427, a planet that is as big as Earth but is half the mass of Earth. What can you say about Darren's weight in this planet?
  11. science

    Darren the astronaut traveled to Planet U-427, a planet that is as big as Earth but is half the mass of Earth. What can you say about Darren's weight in this planet?
  12. Physics

    A body of mass 20kg is transferred from earth (grams=weight newton kg) to another planet where G=2 Newton kg, 1.Wat is the mass on earth? 2.wat is the wieght on earth? 3.wat is the mass on the other planet? 4.wat is the weight on the other planet?
  13. math

    A body of mass 20kg is transferred from earth (grams=weight newton kg) to another planet where G=2 Newton kg, 1.Wat is the mass on earth? 2.wat is the wieght on earth? 3.wat is the mass on the other planet? 4.wat is the weight on the other planet?
  14. Physics

    A body of mass 20kg is transferred from earth (grams=weight newton kg) to another planet where G=2 Newton kg, 1.Wat is the mass on earth? 2.wat is the wieght on earth? 3.wat is the mass on the other planet? 4.wat is the weight on the other planet?
  15. Math

    How high does the satellite have to be in order to see two cities at the same time if the cities are 2250 mi apart? (Round your answer to the nearest mile I thought it was 225 but I was wrong please help
  16. Physics

    A 54100 kg space ship has completed two thirds of its journey from the earth to the Moon. At this position, what magnitude force would the ship's engines have to supply to be the equilibrant? Assume the mass of the moon is 7.35E + 22 kg and the distance
  17. Math

    Monica stepped outside and began to think how fast she is moving even when she is standing still. Assume that the earth is a sphere with a radius of 3960 miles and Monica is at a latitude of 13∘N. What is Monica's speed due solely to the rotation of
  18. Physics Problem 6.20

    The center of a 1.10 diameter spherical pocket of oil is 1.10 beneath the Earth's surface. Estimate by what percentage directly above the pocket of oil would differ from the expected value of for a uniform Earth? Assume the density of oil is
  19. Physics

    The center of a 1.50 diameter spherical pocket of oil is 1.20 beneath the Earth's surface. Estimate by what percentage directly above the pocket of oil would differ from the expected value of for a uniform Earth? Assume the density of oil is 800 kg/m^3.
  20. physics

    1. the average distance separating the Earth and the Moon is 384 000 km. Use the data table 7.3 to find the net gravitational force the eath and the moon exerts on a 3.00*10^4-kg spaceship located halfway between them. TABLE 7.3 <--- for the moon and
  21. Physics

    The center of a 1.50 diameter spherical pocket of oil is 1.20 beneath the Earth's surface. Estimate by what percentage directly above the pocket of oil would differ from the expected value of for a uniform Earth? Assume the density of oil is 800 kg/m^3.
  22. Mathematics

    Monica stepped outside and began to think how fast she is moving even when she is standing still. Assume that the earth is a sphere with a radius of 3960 miles and Monica is at a latitude of 13∘N. What is Monica's speed due solely to the rotation of
  23. MATH HELP

    Monica stepped outside and began to think how fast she is moving even when she is standing still. Assume that the earth is a sphere with a radius of 3960 miles and Monica is at a latitude of 13∘N. What is Monica's speed due solely to the rotation of
  24. Math

    Monica stepped outside and began to think how fast she is moving even when she is standing still. Assume that the earth is a sphere with a radius of 3960 miles and Monica is at a latitude of 13∘N. What is Monica's speed due solely to the rotation of
  25. Physics

    The orbital period of the moon about the earth is approximately 27.3 days. given that the average earth-moon distance is 384,000 kilometers, predict the moon's speed using the expression for centripetal force and the gravitational force, setting them equal
  26. Space craft

    How will you overcome these challenges with the design of your spacecraft? (I decided to choose the inner planet mercury) I put: Mercury is very different than Earth. It’s far rougher than earth; the main problem is the temperature. Humans can’t just
  27. Chemistry

    Which of the following is an example of quantization? A. The amount of time spent in a classroom B. The number of students in a classroom C. Learning happening in a classroom D. The temperature range in a classroom I know I asked this question but I would
  28. physics

    A 42 mT magnetic field points due west. If a proton of kinetic energy 9x10E-12 J enters this field in an upward direction, find the magnetic force acting on the proton in magnitude and direction. What magnetic force would an electron experience due to
  29. physicss

    an. Electron travels in a circular orbit of radius 0.5 a and frequency of 5.5*10^7hz. Findthe magnetic field produced At center
  30. science

    According to Kepler's law of harmonies, which of these planets takes the longest to orbit the Sun? mars jupitor venus neptune
  31. Math(Dynamics)

    To find the time taken by a planet to describe a given arc of its elliptic orbit starting from the nearer and of the major axis.
  32. physics

    Show that the critical velocity of body revolving in cercular orbit very close to the surface of a planet of radiuis R and meandencity.
  33. science

    According to Kepler's law of harmonies, which of these planets takes the longest to orbit the Sun? mars jupitor venus neptune
  34. Physics

    A triply ionized beryllium atom (Be3+) has only one electron in orbit about the nucleus. What is the radius of the ion when it is in the n = 9 excited state?
  35. physicss

    an. Electron travels in a circular orbit of radius 0.5 a and frequency of 5.5*10^7hz. Findthe magnetic field produced At center
  36. astronomy

    1. The radius of the Sun is 7 X 10^5 kilometers. Use powers of ten to show that the Sun's radius is about 100 times the Earth's radius. 2. Given that an astronomical unit is 1.5 X 10^8 kilometers and a light-year is about 10^13 kilometers, how many AU are
  37. Physics

    How far above the surface of the Earth does an object have to be in order for it to have a weight which is 0.53 times the same weight as it would have on the surface of the Moon? (Ignore any effects from the Earth's gravity for the object on the Moon's
  38. Earth Science

    In recent years, scientists have been concerned about decrease in the ozone content of earth’s upper atmosphere. What is the principle threat to humans if this decrease in ozone continues? My answer is, Decreasing precipitation leading to crop failure
  39. physics

    You are explaining to a friend why the crew of the International Space Station feels weightless while orbiting the Earth. Your friend responds that he thought gravity was just a lot weaker up there. Show that it isn’t so by calculating the acceleration
  40. additional science: physics

    Hello i have 2 questions in total. 1) The meteor enters the Earth’s atmosphere with an acceleration of approximately 9.7 m/s2 and with a force acting on it of 1.94 N. What is the mass of the meteor? Show your calculations. 2) Compare this value of the
  41. physic 1

    The sun is more massive than the moon, but the sun is farther from the earth. Which one exerts a greater gravitational force on a person standing on the earth? Give your answer by determining the ratio Fsun/Fmoon of the magnitudes of the gravitational
  42. Physics

    The sun is more massive than the moon, but the sun is farther from the earth. Which one exerts a greater gravitational force on a person standing on the earth? Give your answer by determining the ratio Fsun/Fmoon of the magnitudes of the gravitational
  43. physics 1

    The sun is more massive than the moon, but the sun is farther from the earth. Which one exerts a greater gravitational force on a person standing on the earth? Give your answer by determining the ratio Fsun/Fmoon of the magnitudes of the gravitational
  44. Will somebody help me please?

    1. Diarrhea can be caused by a change in diet and different minerals in the water. True False 2. Fusion produces less radioactivity than fission. True False 3. Wise travelers eat only cooked vegetables in underdeveloped areas. True False 4. The kilogram is
  45. I need help..

    1. Diarrhea can be caused by a change in diet and different minerals in the water. True False 2. Fusion produces less radioactivity than fission. True False 3. Wise travelers eat only cooked vegetables in underdeveloped areas. True False 4. The kilogram is
  46. help!

    A horizontal translation is applied to the graph of y= X^ 3 + 2 so that it will pass through (3, 10) what is the new equation for the graph? how do I do this? When x=3, one wants y to be 10 y= (x+a)^3 + 2 20= (3+a)^3 + 2 solve for a. I would change it to
  47. Science..physics

    The moon is the Earth's nearest neighbour in space. The radius of the moon is approximately one quarter of the Earth's radius, and its mass is one eightieth of the Earth's mass. a) Culculate the weight of a man with a mass of 80kg on the surface of the
  48. chem

    1. The total power used by humans worldwide is approximately 15 TW (terawatts). Sunlight striking the Earth provides 1.336 kW per square meter (assuming no clouds). The surface area of Earth is approximately 197,000,000 square miles. How much of Earth’s
  49. chem

    Global warming refers to the rise in average global temperature due to the increased concentration of certain gases, called greenhouse gases, in our atmosphere. Earth¡¯s oceans, because of their high heat capacity, can absorb heat and therefore act to
  50. physics

    The center of a 1.00km diameter spherical pocket of oil is 1.00kkm beneath the Earth's surface. Estimate by what percentage g directly above the pocket of oil would differ from the expected value of for a uniform Earth? Assume the density of oil is
  51. physics

    a projectile is ejected from a 25 m high tower with a velocity of 40 m/s at an angle of 30 degrees to the horizontal first on Earth and then on Mars. What is the ratio of the time taken to hit the ground on Mars compared to Earth? (Assume gravity on mars =
  52. phys sci

    the space shuttle orbits at an altitude of approximately 200 km above the surface of the earth. If the radius of the earth itself is 6380km, what is the acceleration due to gravity at the altitude ofthe space shuttle?
  53. physics

    A. how long will it take for a 55.0 kg steel brick to fall 75 meters on earth. A. how far from the base will a 55.o kg steel brick to land,(horizontally) if it dropped a vertical distance of 75 meters on earth, and what is its velocity just before it hits
  54. Physics

    the temperature at the surface of the sun is approximatly at 5700K and the temperature at the surface of the earth is approxiamtly 290 K. what entropy change occurs when 1100 J of energy is transfered by radiation from the sun to the earth?
  55. Physics

    The acceleration due to gravity on the moon is about one sixth its value on earth. If a baseball reaches a height of 62 m when thrown upward by someone on the earth, what height would it reach when thrown in the same way on the surface of the moon? Answer
  56. Physics

    The surface of the Sun is approximately 5,650 K, and the temperature of the Earth's surface is approximately 295 K. What entropy change occurs when 6,000 J of energy is transferred by heat from the Sun to the Earth? ______J/K
  57. Physics

    A 8.6-kg rock and a 5.9 × 10-4-kg pebble are held near the surface of the earth. (a) Determine the magnitude of the gravitational force exerted on each by the earth. (b) Calculate the magnitude of the acceleration of each object when released. For b),
  58. physics

    The acceleration due to gravity on the moon is about one-sixth its value on earth. If a baseball reaches a height of 78 m when thrown upward by someone on the earth, what height would it reach when thrown in the same way on the surface of the moon? Answer
  59. Physics

    The surface of the Sun is approximately 5,650 K, and the temperature of the Earth's surface is approximately 295 K. What entropy change occurs when 6,000 J of energy is transferred by heat from the Sun to the Earth? (J/K)
  60. physics

    The acceleration due to gravity on planet X is one fifth that on the surface of the earth. If it takes 4.6 s for an object to fall a certain distance from rest on earth, how long would it take to fall the same distance on planet X? Answer in units of s
  61. physics

    The acceleration due to gravity on planet X is one fifth that on the surface of the earth. If it takes 3.5 s for an object to fall a certain distance from rest on earth, how long would it take to fall the same distance on planet X? Answer in units of s.
  62. Physics

    An astronaut wearing a spacesuit can jump 0.5 m vertically at the surface of the earth. The gravitational acceleration on Mars is 0.4 times that on the earth. If her takeoff velocity is the same, how high can the astronaut jump on Mars?
  63. Physics

    The weight of an object on Earth is 350 newtons. On Mars, the same object would weigh 134 newtons. What is the acceleration due to gravity on the surface of Mars, given that it is 9.8 meters/second2 on Earth?
  64. physics

    A plumb bob does not hang exactly along a line directed to the center of the Earth's rotation. How much does the plumb bob deviate from a radial line at 38.5° north latitude? Assume that the Earth is spherical
  65. college math

    the half life of Uranium -238 is 4.5 billion years and the age of earth is 4.5 X 109 years. What fraction of Uranium-238 that was present when earth was formed still remains?
  66. Physics

    If a projectile is launched from Earth with a speed equal to the escape speed, how high above the Earth's surface is it when its speed is three-fifths the escape speed? I keep getting the answer 2.56x10^6 m after solving it a few different ways. Help would
  67. phys science

    A space shuttle orbits at an altitude of approximately 200km above the surface of the Earth. If the radius of the Earth itself is 6380 km, what’s the acceleration due to gravity at the altitude of the space shuttle?
  68. Math

    The surface area of a sphere is given by the formula 4pi r2, where is it's radius. Although the shape of earth is noth exactly spherical, it has an average radius of 3960 miles. Estimate the surface area of earth.
  69. English

    Read the following paragraph from "Five Hours to Simla." After the cacophony of screeching brakes and grinding gears, there followed the comparatively static hum of engines, and drivers waited in exasperation for the next lurch forwards. For the moment
  70. Please guys. Help me out.

    1. Diarrhea can be caused by a change in diet and different minerals in the water. True False 2. Fusion produces less radioactivity than fission. True False 3. Wise travelers eat only cooked vegetables in underdeveloped areas. True False 4. The kilogram is
  71. political science

    An important reason for why public policy and public opinion may not coincide in the United States is that... a) the American system of government includes arrangements, such as an appointed judiciary, which may produce policy decisions that run contraty
  72. Physics

    The acceleration due to gravity on the moon is about one-sixth its value on earth. If a baseball reaches a height of 64 m when thrown upward by someone on the earth, what height would it reach when thrown in the same way on the surface of the moon? Answer
  73. Science

    How sediments,fossil, and ice core record Earth's geologic history? It record Earth's geologic history by giving scientist an idea of when certain climates or events happen.(Is this a good answer?) Thanks
  74. physics

    1) write the formula to find the magnitude of gravitational force between earth and an object on earth's surface 2) how does the value of gravitational force 'f'change between two objects? 3) what is direction of an object moving with an acceleration due
  75. physics

    The electron gun in a color TV accelerates the electrons through about 25,000 Volts. Estimate the acceleration of such an electron due to the magnetic field of the earth. Hint: In Atlanta, the Earth's magnetic field has a magnitude of about 5.2 X 10-5 T.
  76. Physics

    he weight of an astronaut on the moon is 127 N, where the value of 'g' is only 1.7 m/s2. What would the weight of this astronaut be on the Earth (in N)? I don't know if my attempt is rite? 127n/1.5ms^2 74.70N Divide 74.70N with earth value of G. What is
  77. Physics

    In New Hampshire the average horizontal component of Earth's magnetic field in 1912 was 16 uT, and the average inclination or "dip" was 73 degrees. What was the corresponding mag-nitude of Earth's magnetic field?
  78. physics

    The diameter of some celestial body is 3080 km. What is the volume of this body? _____m3 How many of these celestial bodies would be needed to create a volume equal to that of Earth? The radius of the Earth is 6.38 106 m.
  79. Science

    The largest planets in the solar system are a) located between Earth and Jupiter b)found between Mars and Pluto c) located between the sun and the earth d) scattered througthout the solar system e) none of these e
  80. Physics

    The diameter of some celestial body is 3080 km. What is the volume of this body? _____m3 How many of these celestial bodies would be needed to create a volume equal to that of Earth? The radius of the Earth is 6.38 106 m.
  81. Physics

    A 2.00 ✕ 106 Hz radio signal is sent a distance of 7.30 ✕ 1010 meters from Earth to a spaceship orbiting Mars. Approximately how much time does it take the radio signal to travel from Earth to the spaceship?
  82. Physical science

    The diameter of the planet saturn is 10 times that of the earth but the mass of the planet is only 90 times greater than that of the earth.what isthe gravitational acceleration(or number of 'gs'you"ll feel)on saturn?
  83. science

    1) The force of gravity on the moon is 1/6 the force of gravity on earth. If you had a 1 kg box of cereal on earth which had a weight of 2.4 N, what would its mass be on the moon? why? 2) what is the volume of a textbook with dimensions 21.3 cm, 27.5 cm,
  84. physics

    A 4.92E+2 kg hot-air balloon takes off from rest at the surface of the earth. The nonconservative wind and lift forces take the balloon up, doing +9.81E+4 J of work on the balloon in the process. At what height above the surface of the earth does the
  85. SCIENCE

    Suppose an astronomer oberserves a huge solar flare. Predict its effect on Earth in the next day or so. I put it would break satellites and powercuts would happen. But would a huge solar flare kill all people on Earth? Im not sure
  86. physics

    If you weigh 650 N on the earth, what would be your weight on the surface of a neutron star that has the same mass as our sun and a diameter of 15.0 km ? Take the mass of the sun to be ms = 1.99×10^30 kg, the gravitational constant to be G =
  87. Science Somebody Help Me Please..I have a deadline

    1. Diarrhea can be caused by a change in diet and different minerals in the water. True False 2. Fusion produces less radioactivity than fission. True False 3. Wise travelers eat only cooked vegetables in underdeveloped areas. True False 4. The kilogram is
  88. mechanics and heat

    At the same instant that a 0.5 kg ball is dropped from 25 m above earth , a second ball , with a mass of 0.25 kg , is thrown straight upward from earth’s surface with an initial speed of 15 m/s . They move along nearby lines and pass without colliding.
  89. earth science

    Which of the following statements is TRUE? S-waves are able to pass through the Earth's core. Continental-continental plate convergence is reponsible for the creation of mountain ranges. Oceanic crust is on average about 60 - 100 km thick. The Richter
  90. Physics

    A mass of 5Kg is 1st weighed on a balance at the top of a tower 20m high.The man is then suspended from a fine wire 20m long and reweivhed.find the difference in a weight ,assuming that the radius of the earth is 6400km,the mass of the earth is 6×10^24kg
  91. earth science

    22. an illustration of the fact that a sudden and great _____ struck the earth is the millions fo mammoths and other large animals frozen instantly and preserved, whole and undamaged. catastrophe cold front ice age permafrost ice age right This also makes
  92. Physics

    Carbon-15 has a half-life of 5730 years. As observed from Earth, what would the half-life of carbon-15 be if it traveled through space at 25% of the speed of light, relative to Earth?
  93. science

    why does the sun appear to move westward across the sky during the day? a) because earth rotates to the east b) because earth rotates to the west c) because the sun moves in a westerly direction d) because of the way you are looking into the sky
  94. math

    the distance from the sun to earth is about 1.5x10^11 meters. suppose light travels at a speed of 3x10^8 meters per second. About how long does it take light from the sun to reach earth? PLEASE HELP!!!
  95. physical science

    the diameter of the planet saturn is 10 times that of the earth but the mass of the planet is only 90 times greater than that of the earth.what is the gravitational acceleration or number gs you will feel on saturn?(8.8m.s-2)
  96. science

    why does the sun appear to move westward across the sky during the day? a) because earth rotates to the east b) because earth rotates to the west c) because the sun moves in a westerly direction d) because of the way you are looking into the sky
  97. math chem

    Global warming refers to the rise in average global temperature due to the increased concentration of certain gases, called greenhouse gases, in our atmosphere. Earth¡¯s oceans, because of their high heat capacity, can absorb heat and therefore act to
  98. science

    The moon is the earth's nearest neighbor in space the radius of the moon is approximately one quarter of the earth's radius and it's mass is one eightieth of the earth's mass.(a)calculate the weight of an object with a mass of 50.0kg on the surface of the
  99. earth, science

    Which of the following statements describes the development of the geologic time scale? A) Scientists developed the geologic time scale using fossilized remains from Europe and Asia. B) Scientists developed the geologic time scale by studying rock layers
  100. earth science

    briefly explain how earths atmosphere heated? Energy is transferred between the earth's surface and the atmosphere via conduction, convection, and radiation. Conduction is the process by which heat energy is transmitted through contact with neighboring