1. Physics

    The sun is a satellite of Milky Way's galactic central cluster. The sun revolves around this center with a radius of 2.28x10^20 m. and with a period of 2.52x10^8 years. If the universe is 16 billion years old. a) How many times has the galaxy rotated and
  2. geography

    Match each item on the left with an item on the right. Question 1 options: philosophy calling for greater economic equality in society creator of the Kremlin in Moscow country once controlled by the Soviet Union term that means "self-rule" organized
  3. Physics

    This is my homework problem: "The pilot of a plane is flying at 450 mi/hr W 20.0 degrees S relative to the earth. She sees another plane flying at 350 mi/hr N 40.0 degrees W relative to her plane. What was the magnitude and direction of the plane she saw
  4. sdvfsd

    The earth has a specific tilt to it. No the sun appears to move towards the north and the south but through all the time the rays of the sun fall directly at the equator but fall at an inclined level at the other places and hence the seasons change and
  5. ss

    what are latitude and longitude? lines of __________ and lines __________ cross one another. they form a ____________ around the earth. lines of latitude lines of latitude are also called___________ they circle the earth parallel to the_______ they measure
  6. Science please help :)?

    3. which if the following factors determines how long a star will live ? ( 1point ) A . star’s color b. the star’s mass**** c. the star’s diameter d. the star’s distance from the sun 4 . which of the following causes constellations to appear to
  7. Science - Maps and Computers - Please Check

    Please help me with the following: A single ocean color satellite can collect how many data points? A. 2,000 B. 2,000,000 C. 20,000 D. 2,000,000,000 I know the answer is not D, because I got it wrong. I think the answer is mostly A, but I also think it is
  8. Chemistry

    About twenty radioisotopes with ultra-long half-lives, from 82 million years (244- Plutonium) to 6 million billion years (50-Vanadium) are found in the earth’s crust, yet no radioisotopes with half-lives less than 70 million years (146- Samarium) are
  9. Physics

    The mass of a star in a galaxy far, far away, is 2.13 × 105 Earth masses, and the mean distance from the center of this star to the center of a planet with the same mass as our Earth is 7.87 × 108 km. Treating this planet and star as particles, with each
  10. Ap physics 1

    The mass of a star in a galaxy far, far away, is 3.12 × 105 Earth masses, and the mean distance from the center of this star to the center of a planet with the same mass as our Earth is 2.46 × 108 km. Treating this planet and star as particles,with each
  11. Physics

    Two main strategies are employed to deflect an asteroid: destruction or slowing it down by at least 425 s so that the earth can move out of the impact zone. Assume perfect inelastic collision. (a) If we know the speed of the asteroid (va), mass (ma), and
  12. math

    Taking the speed of the radio signal as 3×108 m/s, calculate the time taken for a signal to reach a GPS receiver from a GPS satellite at a position 21 000 km distant from the receiver. Assume that the speed of the signal is unchanged over the whole path
  13. English

    This question is based on the following poem: Seasons are celebrations. A year's a Ferris wheel. Both honor our world's habit of spinning 'round a star. 7. Which one of the following sentences best expresses the main idea of this poem? A. The world has a
  14. physics

    In Bohr's model of the hydrogen atom, the radius of an orbit a. is proportional to n2. b. is smallest for the highest energy state. c. increases when a photon of light is emitted from an excited atom. d. can have any value that is larger than the
  15. Physics

    On the earth, you throw an object up in the air at some velocity, v, and it reaches a maximum vertical displacement (max. height if you prefer) of 4.8 meters. If you went to the moon, where the value of the gravitational acceleration of the moon is 1/6 of
  16. Environmental Science

    I need a little help on these, i've posted them a few times but i don't get any answers. 29. A common feature of thermal pollution and artificial eutrophication is that they both a. have sources that are difficult to identify and control b. cause large
  17. Math

    You have 200 feet of fencing to enclose a rectangular plot that borders on a river. If you do not fence the side along the river, find the length and width of the plot that will maximize the area _____________________________________ Among all pairs of
  18. Math

    A year on Mars is 686 Earth Days. (1) Which is longer, a year on Mars or a year on Earth? (2)By how many weeks is it longer? Submit two answers. Please explain how you got the answers. My 1st answer was Mars the 2nd answer I 82 1/2 weeks. Please help
  19. physics

    At the equator, the earth’s field is essentially horizontal; near the north pole, it is nearly vertical. In between, the angle varies. As you move farther north, the dip angle, the angle of the earth’s field below horizontal, steadily increases. Green
  20. physical science

    A kg ball of lead rests next to a 10 kg rock. which statement below is true:a:the lead ball and rock have the same amount of inertia,b:if the lead ball and the rock fell from the same height in a vacuum, the rock would hit the ground first because it is
  21. Physics

    The earth rotates once per day about an axis passing through the north and south poles, an axis that is perpendicular to the plane of the equator. (a) Assuming the earth is a sphere with a radius of 6.38 106 m, determine the speed of a person situated at
  22. astronomy

    Calculate the tidal force experienced by Io. How does it compare to the tidal force experienced by the Moon due to the Earth? What would the Earth-Moon distance (i.e., distance between their centres) need to be in order for the Moon to experience similar
  23. physics

    Calculate the tidal force experienced by Io. How does it compare to the tidal force experienced by the Moon due to the Earth? What would the Earth-Moon distance (i.e., distance between their centres) need to be in order for the Moon to experience similar
  24. Math (Physics)

    Problem: An excited hydrogen atom could, in principle, have a radius of 2.50 mm . ________ Part A: What would be the value of n for a Bohr orbit of this size? Answer--> n= 6.87×103 _______ Part B What would its energy be? Answer--> E=_______eV
  25. Math

    Uranus is approximately 2.74 x 10^9 km away from the Sun at perihelion and 3.00 x 10^9 km at aphelion. Find the eccentricity of Uranus's orbit given that the perihelion is r = a(1 - e) and the aphelion is r = a(1 + e).
  26. geology

    How old are the oldest meteorites yet studied and what is the minimum age of Earth since Earth is at least as old as the meteorites. We know the oldest meteorites contain equal amounts of uranium 238 and lead 206. Uranium 238 has a half life of 4.5 billion
  27. GLOBE/GEOGRAPHY HELP

    Rotate the Earth using the arrows on the globe that show the direction of rotation. As viewed from the North Pole, what direction is the Earth spinning? clockwise or counter-clockwise? I suggest you do this exercise in class, since that globe apparently
  28. Science- Earth and its History

    What can scientists learn from the rate at which radioactive elements decay? A. a rock's absolute age* B. the relative age of rock layers C. where one soil horizon ends and the next begins D. the difference between molds and casts. After six half-lives,
  29. Physics

    a particle (C) of mass m = 0.2 kg can slide without friction on an inclined plane making an angle alfa (a) = 30 degrees with respect to the horizontal (aka ground) . (C) is launched at at an instant to=0 along a line Ox of greatest slope with an initial
  30. French

    Hi, I'm doing a french crossword puzzle and I need you to check the words that I filled in the blank. 1. C'est un boutique très élégante. Les -------- sont chers. Answer: Prix 2. A(with an accent) mon ---------, le blouson vert est plus joli que le
  31. global

    why could it be said that the historic period is only a minute in comparison ti the 24 hours of the day? The historic period began about 5,000 years ago when writing was first developed in Mesopotamia (now Iraq). Modern man has existed for at least 100,000
  32. Physics

    The weight of an astronaut plus his space suit on the Moon is only 270 N. A. How much do they weigh on Earth, in Newtons, assuming the acceleration due to gravity on the moon is 1.67m/s^2= 1584is this right? B. What is the mass of the astronaut and his
  33. Calc

    Recent studies indicate that the average surface temp. of the earth has been rising steadily. Some scientists have modeled the temp. by the linear function T= 0.02t + 8.50, where T is temp. in degrees Celsius and t represents years since 1900. What do the
  34. Physics (please check)

    A 6.0kg block is released from rest 80m above the ground. When it has fallen 60m its kinetic energy is: I got 1200J as my answer mgh=(6.0*9.81* 60m)=3531.6 PE + KE= (ME + KE) 3531.6 + KE= (6.0*9.81*80m) KE= 1177.2 is that right A 6.0 Kg block is thrown up
  35. math

    3. The height H of an object t seconds after it is propelled upward with an initial velocity v is represented by , where g is the gravitational pull and h is the initial height. The gravitational pull of the moon is 1.6 meters per second squared. The
  36. physics

    A man of mass 78.5 kg walks down the aisle of an airplane at a speed of 1.40 m/s in the forward direction while the plane moves at a speed of 320 m/s relative to the earth. (a) Find the man's kinetic energy relative to the plane. (b) Find the man's kinetic
  37. Physics

    A man of mass 75.5 kg walks down the aisle of an airplane at a speed of 1.50 m/s in the forward direction while the plane moves at a speed of 305 m/s relative to the earth. (a) Find the man's kinetic energy relative to the plane. (b) Find the man's kinetic
  38. NCSU

    A man of mass 83.5 kg walks down the aisle of an airplane at a speed of 1.60 m/s in the forward direction while the plane moves at a speed of 295 m/s relative to the earth. (a) Find the man's kinetic energy relative to the plane. (b) Find the man's kinetic
  39. Physics

    An aluminum wire with mass/unit length of p = 5*10^-4 kg/m lies on the ground, running east-west. The wire feels the earth's magnetic field, which has magnitude B = 5*10^-5 T. Assume the wire is in Columbia, where the Earth's magnetic field runs due north,
  40. Earth Science (check answers)

    Describe the importance of maintaining the ocean ecosystem. It is important to maintain because the ocean ecosystems because it provides reefs that support a complex ecosystem of ocean organisms that live and help each other to survive. Virtually every
  41. Math

    Calculate how long a de-orbit burn must last in minutes and seconds to achieve the Shuttle’s change in altitude from 205 miles to 60 miles at perigee.Use the equations and conversions provided below in method 1 or method 2 to find the required burn time
  42. Science-Earth's History

    The geologic time scale originally ordered Earth's rocks by: A. absolute age B. relative age C. composition D. decades and centuries B Where did scientists originally get their information to develop the geologic time scale? A. They collected and studied
  43. World Geo, Help pls

    Please help!!! Which of the following is not true about Aborigine culture? (1 point) It is the oldest surviving culture on Earth. Traditional Aborigine societies formed agricultural settlements. Aborigines do not believe that land belongs to humans.
  44. Geology

    Can someone please look this over and let me know if I described the Plate Tectonic Theory? Thanks. Write a 200-300-word summary about two historical figures and the process of mantle convection and plate movement. Two historical figures that contributed
  45. english fixed-3

    here's what i did for number 4. The world is deserting because we are taking water for granted. If people continue to waste water, the earth’s structure will change and it will be the main cause of earthquake and potentially a tsunami. and for number 5.
  46. physics mc question!!!!HELP

    Question # 1 : It a particle increases its speed by a factor of 2, what happens to the kinetic energy? a)doubles b)cuts in half c)increases by a factor of 4 d)depends on whether or not work is done on the particle Question # 2: An object falling near the
  47. Physics/Astronomy

    A pulsar is a stellar object that emits light in short bursts. Suppose a pulsar with a speed of 0.975c approaches Earth, and a rocket with a speed of 0.999c heads toward the pulsar (both speeds measured in Earth’s frame of reference). If the pulsar emits
  48. science

    An asteroid in an elliptical orbit about the sun travels at 2.0 106 m/s at perihelion (the point of closest approach) at a distance of 3.8 108 km from the sun. How fast is it traveling at aphelion (the most distant point), which is 8.3 108 km from the sun?
  49. physical

    An asteroid in an elliptical orbit about the sun travels at 3.9 106 m/s at perihelion (the point of closest approach) at a distance of 3.7 108 km from the sun. How fast is it traveling at aphelion (the most distant point), which is 8.6 108 km from the sun?
  50. physics

    It has been suggested, and not facetiously, that life might have originated on Mars and been carried to Earth when a meteor hit Mars and blasted pieces of rock (perhaps containing primitive life) free of the surface. Astronomers know that many Martian
  51. Environmental Science

    29. A common feature of thermal pollution and artificial eutrophication is that they both a. have sources that are difficult to identify and control b. cause large mats of algae to bloom in fresh water c. are a result of power plants and other industrial
  52. physics

    A 3Kg projectile is fired straight upward from earth's surface with a speed that is one-fourth the escape speed. Neglecting air resistance. a) What is the Kinetic energy of this projectile when it is launched? b) what is the gravitational potential energy
  53. physics

    The solar wind is a thin, hot gas given off by the sun. Charged particles in this gas enter the magnetic field of the earth and can experience a magnetic force. Suppose a charged particle traveling with a speed of 9.80 x 10^6 m/s encounters the earth's
  54. Physics

    What changed Newton's original work on the movement of the Moon around the Earth into the law of universal gravitation? 1) his conclusion that the same laws applied to all objects, no matter how small 2) his connection of gravitation to his first law 3)
  55. physics

    What changed Newton's original work on the movement of the Moon around the Earth into the law of universal gravitation? 1) his conclusion that the same laws applied to all objects, no matter how small 2) his connection of gravitation to his first law 3)
  56. physics

    What changed Newton's original work on the movement of the Moon around the Earth into the law of universal gravitation? 1) his conclusion that the same laws applied to all objects, no matter how small 2) his connection of gravitation to his first law 3)
  57. Astrophysics

    The Earth formed at a redshift of z∼0.53. That means that when our world was young, the universe was quite a bit smaller than it is today. The nearest galaxies to our own are around 10 kpc (kilo-parsecs) in size, lie at a distance of around 1 Mpc
  58. Physics

    Calculate the work done by planet X on its moon. Planet X applies a force of 5.6 x 10^10 N on its moon and the moon is 4.0 x 10^8 km away from the planet and it continues to circle the planet in a circular orbit of circumference of 2.5 x 10^9 m.
  59. Chemistry - is this correct?

    Write the electronic configuration for nickel(#28). I know it is 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^8 (b) How many electrons are there of highest energy in nickel? Is it 8? (c) how many electrons are there in the outermost energy level(orbit) of nickel? Is
  60. physics

    A dumbbell has a mass m on either end of a rod of length 2a. The center of the dumbbell is a distance r from the center of the Earth, and the dumbbell is aligned radially. If r≫a, the difference in the gravitational force exerted on the two masses by
  61. Physics Help

    A dumbbell has a mass m on either end of a rod of length 2a. The center of the dumbbell is a distance r from the center of the Earth, and the dumbbell is aligned radially. If r≫a, the difference in the gravitational force exerted on the two masses by
  62. science

    I am studying science at GCSE. I a working through a revision book and have come across a question which i am unsure of the answer. The question is, "state the number of different elements present in C6H5CO2Na." The answer i have is 14 but still i am
  63. KUSSSESSS

    Consider a wire of length L = 0.30 m that runs north-south on a horizontal surface. There is a current of I = 0.50 A flowing north in the wire. (The rest of the circuit, which actually delivers this current, is not shown.) The Earth's magnetic field at
  64. Science

    In __, the amplitude of the carrier wave is changed to transmit information; the frequency is not changed. In __, the frequency of the carrier wave is changed __ phones and __ phones use radio waves to transmit signals. __ use electromagnetic signals from
  65. people

    1. Many people know that the weight of an object varies on different planets, but did you know that the weight of an object on Earth also varies according to the elevation of the object? In particular, the weight of an object follows this equation: , where
  66. science

    Hi it's me again. I realize that my last question didn't make much sense, so I will try to explain it again. Her it goes..... A long time ago the Mayans predicted that it took so many days( years even) for the sun to orbit the jupiter. This was without any
  67. physics

    1. The acceleration due to gravity calculated this way works well for objects near the Earth’s surface. How would you have to change the above equation if the object was 100,000 meters above the ground? (Note: this question refers to Newton’s equation
  68. physics

    1. The acceleration due to gravity calculated this way works well for objects near the Earth’s surface. How would you have to change the above equation if the object was 100,000 meters above the ground? (Note: this question refers to Newton’s equation
  69. Physics

    The Earth's magnetic field above the Earth's equator is about 10^-4 north. If a proton is intially moving downward at 5*10^5 m/s, it will? A. curve east, making a circle with r= 50 m. B. curve west, making a circle with r=50 cm C. curve east, making a
  70. Word problem

    earth and cement block filling a box weighs 390mlb.the block weigh 2.4times as much as water and earth weighs 1.5times as much as water.water filling the box weighs 2000lb.find the weigh of the cement block.bl? plz help help help!!!! Show work
  71. Physics

    Obi-Wan lands his spacecraft on an unknown planet. Visibility is poor, so he isn't able to exactly determine on which planet he has landed. He finds someone on a local communications channel and asks for directions to Earth. "You are already on Earth," is
  72. science

    What is the geologic time scale and what are some thing scientists use it for (at least two things)? Here's my answer could you please verify. the geologic time scale is a record of the geologic events and life forms in Earth’s history. Scientists use it
  73. physics

    A treasure map you uncovered while vacationing on the Spanish Coast reads as follows: "If me treasure ye wants, me hoard ye'll have, just follow thee directions these. Step to the south from Brisbain's Mouth, 6 paces through the trees. Then to the west, 10
  74. physics

    On planet x, an object weighs 10.4N. On planet B where the magnitude of the free fall acceleration is 1.48g (where g=9.8 m/s^2 is the gravitational acceleration on Earth),the object weighs 24.6N. The acceleration of gravity is 9.8 m/s^2. What is the mass
  75. trig

    L ii i i i i i i i i A i i i i i i i i i i 4000 miles i i i i E ii right triangle have to find side EL. The range of a lighthouse is the maximum distance at which its light is visible. In the figure, point A is the farthest point from which it is possible
  76. 7th grade Science help

    1. _______ is energy that flows from an object with a higher temperature to an object with a lower temperature. (1 point) Heat Radiation Potential Chemical 2. The transfer of energy that occurs when molecules bump into one another is called _____. (1
  77. Physics

    The sun has a mass of 1.99x10 30 kg the earth has a mass of 5.98x10 24 kg and is 1.496x10 11 m from the sun a) Calculate the force of gravity acting on the eaarth by the sun b) CAlculate the force of gravity acting on the sun by the earth
  78. analytical question

    One application of emission in remote sensing is in the detection of forest fires. The Landsat satellite has a sensor that detects active fires by examining their emission in the wavelength region of 1.55 μm to 1.75 μm. a. What type of light is
  79. Science- PLEASE, this is due tomorrow for test!

    What is the section of EMS of satellite phones? What wavelength and frequency does it use? are there any dangers in using it? What is the wavelength and frequency of pagers? are there any dangers in using it? Is there any danger in using cordless phones?
  80. chemistry

    A NASA satellite showed that in 2003 the ozone hole was much larger than it was in 2002. The 2003 hole measured 1.04 x 107 mi2 in diameter, while the diameter of the 2002 hole was 6.9 x 106 mi2 Calculate the difference in size between the two holes in
  81. reading

    Scientists generally agree that Earth is getting warmer due to what's called the greenhouse effect. A greenhouse used for plants stays warm because sunlight and heat coming through the glass roof are mostly trapped. The heat doesn't radiate back into the
  82. Earth science

    TRUE OR FALSE The burning of fossil fuels cause the earth to get warmer by putting carbon dioxide in the atmosphere and the carbon dioxide traps heat. MY GUESS: TRUE Isobars help meteorologists find fronts on weather maps. MY GUESS: FALSE A CLOUD IS A
  83. Science

    In the early 1900s, Alfred Wegener noticed that some of the Earth's continents looked like they might fit together like a jigsaw puzzle. He also observed that the continents that looked like they fit together had similar plants, animals, and rock
  84. Physics

    Your dog has been diagnosed with a terminal illness for which there is no cure. The Veterinarian expects that it will live for 1 year before it succumbs to the condition. You have the idea that if you could keep the dog alive a little longer, a cure might
  85. Math

    Hello ma’am sir.. I have a problem in my assignment.. I‘m now a college student…a first year student…this is my question..please help me.. I really need it now… 1. The diameter of the earth is 7920 miles, and that of the moon is 2160 miles.
  86. math

    2/3x+5/3x=14 7\6x=14 then multiply a4 my 6\7 what is the circumferenceof a satellite dish which has a diameter of 21m you do 2 times pie and radius since you have the diameter then its 21 times pie . for futher info if your trying to find the area then you
  87. physics

    is this right? a 50kg barbell can be lifted by usinga force of 180 N. what is the force of gravity on this planet? if the same barbell is lifted on earth, what minimal force is needed? -i got 3.6 for gravity of the unnamed planet; and 49 N for the minimal
  88. Physics

    mass rubber stopper = 0.07Kg mass metal washers = 0.196Kg radius= 1.0m total time = 12 seconds # of revolutions = 10 revolutions With this data, calculate the Period (T) of the rubber stopper in its "orbit".
  89. Language

    People have been making maps for hundreds of years. Christopher Columbus used maps when he sailed to the "New World." At that time, most people thought Earth was flat, and all of the maps they used were flat, too. Of course, Columbus's maps were not
  90. trig

    Since its construction in 1821, Marblehead Lighthouse has stood at the entrance to Sandusky Bay, guiding sailors along Lake Erie’s rocky shores. The 65-foot tower is one of Ohio’s best-known landmarks and the oldest continuously operating lighthouse on
  91. geometry

    A satellite launch rocket has a cylindrical fuel tank. The fuel tank can hold V cubic meters of fuel. If the tank measures d meters across, what is the height of the tank in meters?
  92. MISSION

    A satellite launch rocket has a cylindrical fuel tank. The fuel tank can hold V cubic meters of fuel. If the tank measures d meters across, what is the height of the tank in meters?
  93. Math

    A satellite launch rocket has a cylindrical fuel tank. The fuel tank can hold V cubic meters of fuel. If the tank measures d meters across, what is the height of the tank in meters?
  94. HADS

    Find the acceleration of the following reference frames i)when a reference frame fixed to the surface of the Earth at latitude 37 degree.ii)A reference frame with origin at the center of Earth with one axis always pointing toward the Sun. iii)A reference
  95. Physics

    Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 1.9-kg projectile from rest to a speed of 5.1 × 103 m/s. The net force accelerating the projectile is 8.6
  96. math

    Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 7.9-kg projectile from rest to a speed of 2.8 × 103 m/s. The net force accelerating the projectile
  97. science

    Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 4.8-kg projectile from rest to a speed of 3.9 103 m/s. The net force accelerating the projectile is 4.8
  98. physicsh

    Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 4.8-kg projectile from rest to a speed of 3.9 103 m/s. The net force accelerating the projectile is 4.8
  99. PHYSICS

    Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 8.9-kg projectile from rest to a speed of 4.2 × 103 m/s. The net force accelerating the projectile is 1.4
  100. physics

    Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 9.7-kg projectile from rest to a speed of 6.5 × 103 m/s. The net force accelerating the projectile is 8.0