1. Physics

    Some spacecraft design uses a solar sail made of aluminized plastic. As sunlight reflects off the sail, radiation pressure drives the spacecraft outward away from the sun. a. If the sail material has a density of 700.0 kg/m3, what is the maximum thickness
  2. physics

    need help with the following question. if earth has a mass of 6.0*10^24 kg and a radius 6.4*10^6 m: a) find the change in gravitational potential energy of a meteorite of mass 150 kg as it moves from an infinite distance to the earth's surface. b) with
  3. english part 1

    Which of the following best expresses the writer's main idea in “Single Room, Earth View”? A. Space exploration leads to human progress. B. Space travel offers a unique view of Earth. C. Astronauts are highly trained scientists. D. Pollution is
  4. physics

    Star Z has 1/5 the radius of Earth and 1000 times the Earth's mass. If a mass weighs 1.0 N on Earth, what does it weight on Star Z?
  5. physics

    Star Z has 1/5 the radius of Earth and 1000 times the Earth's mass. If a mass weighs 1.0 N on Earth, what does it weight on Star Z?
  6. 12th

    an electron above the earth is balanced by the gravitational force and the electric field of the earth. find the electric field of the earth.
  7. physics

    Star Z has 1/5 the radius of Earth and 1000 times the Earth's mass. If a mass weighs 1.0 N on Earth, what does it weight on Star Z? Thank you.
  8. physics

    The radius of Earth is about 6.38 103 km. A 7.40 103 N spacecraft travels away from Earth. What is the weight of the spacecraft at the following distances from Earth's surface?
  9. Physics

    In the approximation that the Earth is a sphere of uniform density, it can be shown that the gravitational force it exerts on a mass m inside the Earth at a distance r from the center is mg(r/R), where R is the radius of the Earth. (Note that at the the
  10. Physics & Gravity

    The acceleration due to gravity on the moon is about one-sixth its value on earth. If a baseball reaches a height of 51 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
  11. Astronomy (algebra-based physics)

    Extrasolar planets There are currently 340 known extrasolar planets, i.e., planets around other suns. Most of them we infer only by their gravitational pull on their host stars, and a handful appear to dim the light of their host star as they transit in
  12. science

    Which motion causes night and day on Earth? A. the Sun’s motion around its axis B. Earth’s motion around its axis*** C. Earth’s motion around the Sun D. the Moon’s motion around Earth I think the answer is B, but am I correct?
  13. science

    Meteorites can make large depressions on Earth’s surface when they make impact. Why are so few of these depressions visible on Earth’s surface? • Earth is constantly changing it’s topography due to volcanic activity, or processes such as
  14. physics

    Sally has a mass of 58.0 kg and Earth has a mass of 5.98 1024 kg. The radius of Earth is 6.371 106 m. What is the force of gravitational attraction between Sally and Earth? What is Sally's weight?
  15. science

    does jupiter have a clockwise or counterr-clockwise rotation? Both. It depends on the direction you are looking. For instance, looking at the Earth, from the South of Earth, Earth has clockwise rotation. But looking at it from the North, is is
  16. Math

    There are about 7 billion people on Earth. Suppose that they all lined up and held hands, each person taking about 2 yards of space. a. How long a line would the people form? b. The circumference of the Earth is about 25,000 miles at the equator. How many
  17. English

    Could you please check these sentences? Thank you. 1) In the conventional society of Jane Austen’s day, a woman’s role was fairly clear. Her position in life was defined by her father or her husband and she was expected to be modest, submissive and
  18. physics

    Consider the Earth and the Moon as a two-particle system. (a) Find the gravitational field of this two-particle system at the point that is exactly halfway between the Earth and the Moon. (Assume a radial direction r̂ from the Earth to the Moon. Express
  19. Physics-VASTS

    The Mass Budget: Mars Reconnaissance Orbiter Repair Mission Operational Concept Math Problem: The Mars Reconnaissance Orbiter (MRO) has encountered a failure in its High Resolution Imaging Science Experiment (HiRISE) camera. Mission Case: As the HiRISE
  20. College Physics

    n the approximation that the Earth is a sphere of uniform density, it can be shown that the gravitational force it exerts on a mass m inside the Earth at a distance r from the center is mg(r/R), where R is the radius of the Earth. (Note that at the the
  21. Geography

    (Use the drop-down menu to complete the sentence) As one side of Earth turns away from the sun, [Options] A.) The Sun moves with it. B.) The Sun appears to rise on that side of Earth. C.) The Sun appears to set on that side of Earth. D.) The Sun moves to
  22. Physics

    Take into account the Earth's rotational speed (1 rev/day) and determine the necessary speed, with respect to the Earth, for a rocket to escape if fired from the Earth at the equator in a direction a) eastward; b) westward; c) vertically upward. The
  23. Physics

    Take into account the Earth's rotational speed (1 rev/day) and determine the necessary speed, with respect to the Earth, for a rocket to escape if fired from the Earth at the equator in a direction a) eastward; b) westward; c) vertically upward. The
  24. Earth Science

    Why is it generally warmer in a rural area than in an urban area? I have a question: How does the earth's surface heat up or cool down? My answer: the sun heats up the earth darker surfaces are warmer than cooler surfaces. Please help.
  25. Physics 2

    what magnetic force would an electron experience due to Earth’s magnetic field if it were moving at 3x10E6 m/s directly away from earth’s surface? (Earth’s B-field in the region is parallel to the surface and has a strength of 550 µT)
  26. Science

    A Space Traveller determine the radius of a Planet to be half that of the earth after landing on its surface he find the acceleration due to gravity to be twice of the surface of the earth find the ratio of the mass of a planet to the earth
  27. algebra

    The force of gravity is inversely proportional to the square of the center of the earth. if you weigh 120 lbs on the surface of the earth, how much would you weigh 250 miles above the surface? (Earth's radius = 4000 miles)
  28. physics

    How much additional energy is needed to fire a 7.2 × 10^2 kg weather monitor on the earth’s surface to a height of 120 km above the earth? (rE = 6.38 × 10^6 m, ME = 5.98 × 10^24 kg) Assume that the weather monitor rises to that height, stops, and
  29. Physics help please

    The space shuttle orbits at a distance of 335 km above the surface of the Earth. What is the gravitational force (in N) on a 1.0 kg sphere inside the space shuttle. Assume that the mass of the Earth is 5.98x1024 kg and the radius of the Earth is 6370 km
  30. Astronomy

    1. Consider an asteroid of radius 2 km and density 2,500 kg/m^3 impacting the Earth. When it collides with the surface its kinetic energy is, to a large extent, dumped into the environment, some as heat vaporizing rock and some as mechanical energy
  31. PLZ HELP MT MIND WILL EXPLODE I DONT UNDERSTAND!!!

    4. Explain the data you will want to collect on your mission, and list the instruments that you’ll need so that you can collect and store samples while on your mission. Describe how any collected data will be used when you return from your mission. 3
  32. Math

    The period of revolution of a planet around the sun is the time it takes for the planet to complete one orbit of the sun. The period, P years, is give by Kepler's third law P^2=D^3, where D is the average distance from the sun in astronomical units (AU).
  33. Physics-mechanics

    A 1.0 kg mass weighs 9.8 N on Earth's surface, and the radius of the Earth is roughly 6.4 x 10^6 m. Calculate the average density of Earth. (Show how you would calculate for density; don't just give the answer because L wan't to understand how you arrived
  34. Physics

    The mean radius of the Earth is R=6.38x10^6m. At what distance above the Earth's surface will the acceleration of gravity be 4.905m/s^2? F_g=(Gmme)/r^2 4.905=6.67x10^-11(5.98x10^24)/r^2 The mass cancel out so that is how I got the above answer. r=9017663m
  35. physics..

    Angular diameter of sun is 17" when measured from north pole and south pole of earth. Calculate distance of sun from earth if diameter of earth is 12800km. kindly help me to solve this question..
  36. Physics

    If the mass of a planet is 0.571 times that of the Earth and its radius is 0.787 times that of the Earth, estimate the gravitational field g at the surface of the planet. The gravitational acceleration on Earth is 9.8 m/s2. Answer in units of m/s2
  37. Physics

    If the mass of a planet is 0.103 times that of the Earth and its radius is 0.592 times that of the Earth, estimate the gravitational field g at the surface of the planet. The gravitational acceleration on Earth is 9.8 m/s2. Answer in units of m/s2
  38. Physics

    Because of the Earth's rotation, a plumb bob does not hang exactly along a line directed to the center of the Earth. How much does the plumb bob deviate from a radial line at 35.1° north latitude? Assume the Earth is spherical.
  39. drbob222,math

    Am going correct with this one. It is estimated that the Earth is losing 4000 species of plants and animals every year. If S represents the number of species living last year, how many species are on Earth this year? S-4000=1 S=1+4000 S=4001 of species we
  40. Physics help - Earths force

    Is the force of the earth’s gravity on the sun stronger, weaker, or the same as the force of the sun’s gravity on the earth? Explain why the sun’s attraction affects the motion of the earth more than the earth’s attraction affects the sun’s
  41. maths calculus

    A centre enters students for English levels one and two end test every year. Some take the paper based version, others online version. For planning purposes you need to assume trend patterns indicate that .the total number of entries each year is always
  42. Physics

    A 6.80 x 10^4 kg space shuttle moving at 7.90 x 10^4 m/s reenters the earth's atmosphere 80.0 km above the earth's surface. What is the shuttle's total mechanical energy with respect to earth's surface? I know the answer is E= 2.173 x 10^12J But I don't
  43. science

    the moon's gravity is about one-sixth the gravity on earth. mar's gravity is about one half the gravity on earth. make a bar graph that shows your weight (95 lbs) in newtons on earth, moon, and on mars. A newton is equal to about one quarter of a pound.
  44. World Geography

    REVIEW 1.How do lines of latitude and longitude help geographers study Earth? A. These lines show geographers the direction of Earth’s rotation around the sun. B. These lines help geographers see the difference between oceans and landforms on Earth’s
  45. earth

    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
  46. Law

    I have to find key political words for this newspaper article so please check whehter the words i listed is right in the bottom and if there is anything i should add: Government contributes $9m for soldier protection Published on Tue, 14/06/2011, 11:45:04
  47. physics

    when an object is 100m above the surface of earth. The earth's attraction for it is 10N. In order then the earth's attraction on the same object is only 5N. how far should be taken to object be away from surface of earth.
  48. physics-torque

    A person is doing leg lifts with 3.0-kg ankle weights. She is sitting in a chair with her legs bent at a right angle initially. The quadriceps muscles are attached to the patella via a tendon; the patella is connected to the tibia by the patellar tendon,
  49. maths

    The total population of the earth was estimated to be 6.42 billion people.Given that the total land surface area of the earth is about 1.5×10^8km^2.Find the average number of people living in 1 km^2 of land on earth,correct to 2 significant figures.Thanks
  50. physics help!

    The earth attracts a large flying bug toward its center with a force of 0.10 Newtons. With what force does the bug attract the earth itself? 1. 1.0 N 2. 0.10 N 3. Trillions of Newtons 4. 10 N 5. We need the mass of the bug. 6. Zero; the earth
  51. Physics

    Astrology, that unlikely and vague pseudoscience, makes much of the position of the planets at the moment of one’s birth. The only known force a planet exerts on objects on Earth is gravitational. (a) Calculate the gravitational force exerted on a 4.20
  52. Science

    PLEASE CHECK MY ANSWERS :) answers marked below 1. Which of Earth’s spheres contains most of its mass? (1 point) atmosphere *** hydrosphere geosphere biosphere 2. Erosion and weathering are examples of which types of forces? (1 point) constructive forces
  53. Physics

    How many years would it take the planet to orbit the sun. How do you calculate. All I have is, that the planet is 97 times farther from sun than earth or 97 Astronomical units Using Kepler's Law you find that the anser is 97^(1.5) years. You can estimate
  54. physics

    why does the earth have a magnetic declination? a. the earth's axis of rotation is not constant b. the magnetic field of the earth is unknown c. its magnetic poles shift over time and are not aligned to its geographical poles. d. the north and south poles
  55. science

    The true speed of a moving car on the Earth, if you want to be very precise, would be the speed of the car with respect to the ground Is this true? yeah it is true yeah it is true The true speed of a moving car on the Earth, if you want to be very precise,
  56. physics

    a marble is dropped from the top of a skyscraper. Is the work done by earths gravitational force on the marble equal to, smaller than or larger them that done by the marbles gravitational force on earth? Why? newtons 3rd law: force on marble due to earths
  57. English

    Thank you very much for your corrections! Here are other statements on the same newspaper article. 1) The cheetah reintroduction programme is kicking off (starting?) with a meeting of experts in September. 2) The project includes the foundation of a
  58. Astronomy

    Suppose the Moon is at a (center-to-center) distance D from Earth. Find an exact expression for the magnitude of the tidal force applied by Earth to our rock of mass m in terms of D, m, the mass of Earth Me (input as M_e), and the lunar radius Rm (input as
  59. Physics Please help!

    Calculate the position of the center of mass of the following pairs of objects. Use acoordinate system where the origin is at the center of the more massive object. Give youranswer not in meters but as a fraction of the radius as requested. Get data from
  60. physics

    A certain pendulum on Earth has a period of 1.6 s. What would be the period of this pendulum if it were taken to another planet that had 1.75 times the mass of the Earth and 2.5 times the Earth's radius? Express your answer in seconds to three significant
  61. physics

    If the earth acceleration due to gravity on a mass of 2000kg on the earth surface is 10ms.What will be the acceleration due to gravity when it is at a point twice the radius of the earth.What is the gravitational force on it.
  62. English

    I left out a few more sentences I'm really doubful about. Thank you very much for helping me. 1) In the summer my village is very lively. There are a lot of tourists who spend their holiday in bed and breakfasts and go to restaurants. 2) You didn't vary a
  63. Physics

    Assuming that the Earth is spherical and recalling that latitudes range from 0° at the Equator to 90° N at the North Pole, how far apart, measured on the Earth's surface, are Copenhagen (55.67° N latitude), and Rome (41.90° N latitude)? The two cities
  64. PHYSICS

    If your mass on earth is 70 kg what will be your mass on the moon considering that the gravitational field strength on the moon (g) is 1/6 of that on the earth. (g on earth = 10N/kg)
  65. Physics

    Halleys Comet. Rmin =8.9 x 10^10 m Period of orbit = 2.4 x 10^9 sec 1)What is value of K for Halley's comet? 2)Whats the average radius of Halleys comet orbit? 3)What is value of the aphelion(Rmax) for halley's comet.(Rmin is perihelion. Recall Rave=
  66. Physics

    Halleys Comet. Rmin =8.9 x 10^10 m Period of orbit = 2.4 x 10^9 sec 1)What is value of K for Halley's comet? 2)Whats the average radius of Halleys comet orbit? 3)What is value of the aphelion(Rmax) for halley's comet.(Rmin is perihelion. Recall Rave=
  67. physics

    Early skeptics of the idea of a rotating Earth said that the fast spin of Earth would throw people at the equator into space. The radius of Earth is about 6400 km. Show why this objection is wrong by determining the following information. (a) Calculate the
  68. Physics

    Early skeptics of the idea of a rotating Earth said that the fast spin of Earth would throw people at the equator into space. The radius of Earth is about 6400 km. Show why this objection is wrong by determining the following information. (a) Calculate the
  69. Physics

    Calculate the position of the center of mass of the following pairs of objects. Use acoordinate system where the origin is at the center of the more massive object. Give youranswer not in meters but as a fraction of the radius as requested. Get data from
  70. Physics Question......many thanks

    A projectile is shot directly away from Earth's surface. Neglect the rotation of Earth. (a) As a multiple of Earth's radius RE, what is the radial distance a projectile reaches if its initial speed is one-fifth of the escape speed from Earth? ____ times RE
  71. Physics

    A 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. Find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earth’s velocity. Earth’s mass is 6.0 × 1024 kg. Show
  72. Physics

    X-ray pulses from Cygnus X-1, a celestial x- ray source, have been recorded during high- altitude rocket flights. The signals can be interpreted as originating when a blob of ion- ized matter orbits a black hole with a period of 7.84 ms. If the blob were
  73. Physics

    Early skeptics of the idea of a rotating Earth said that the fast spin of Earth would throw people at the equator into space. The radius of Earth is about 6400 km. Show why this objection is wrong by determining the following information. a.) Calculate the
  74. physics

    Early skeptics of the idea of a rotating Earth said that the fast spin of Earth would throw people at the equator into space. The radius of Earth is about 6400 km. Show why this objection is wrong by determining the following information. a.) Calculate the
  75. Physics

    What is the force of gravity at 220 miles above Earth's surface? Calculate how much of a g force the astronauts are actually experiencing. The solution for this math problem is a percentage. You can calculate it using the Algebraic equation: gr = R2/r2 x g
  76. earth

    The weight (V) of an object on Venus varies directly as its weight (E) on Earth. A person weighing 120 lb on Earth would weigh 106 lb on Venus. How much would a person weighing 180 lb on Earth weigh on Venus?
  77. Calculus

    The radius of Earth at the equator is approximately 4000 miles. Suppose a jet flies once around Earth at a speed of 5000 miles an hour relative to Earth. If the flight path is a negligible height above the equater, then among the following choices, what is
  78. physics

    Angular diameter of sun is 17" when measured from north pole and south pole of earth. Calculate distance of sun from earth if diameter of earth is 12800km.
  79. physics

    Angular diameter of sun is 17" when measured from north pole and south pole of earth. Calculate distance of sun from earth if diameter of earth is 12800km.
  80. English

    My essay, the writing centre told me that my introduction essay was not to the point of being a succesful student. So I changed it. Here, could you please help me rephrase it .. My two most important points are the TWO STEPS : Daily and punctual attendance
  81. maths

    Im confused can any1 help me on this question ?? or try and put me on the right track? (a) A circle has radius 2cm (in that circle there is an triangle AOB) and the chord AB has length 3cm. AO is 2cm and BO is 2cm. O is the centre of the circle. (b)
  82. physics

    Gravity on the moon is only 1/6 as strong as gravity on earth. What is the weight of a 20 kg object on the moon and on earth? I have to find it in Newtons on earth and on the moon. WeightinNewtons= mass* gravity field on earth, the gravity field is
  83. Miami Dade

    X-ray pulses from Cygnus X-1, a celestial x- ray source, have been recorded during high- altitude rocket flights. The signals can be interpreted as originating when a blob of ion- ized matter orbits a black hole with a period of 7.84 ms. If the blob were
  84. geometry

    A total solar eclipse occurs when the moon passes between the earth and the sun, and the darkest shadow cast by the moon, called the umbra, hits the surface of the earth. If the umbra does not hit the surface, as shown in the following figure, then a total
  85. physics

    It is the year 2305 and the tallest structure in the world has an insane height of 3.19×106 m above the surface of the Earth. A pendulum clock that keeps perfect time on the surface of the Earth is placed at the top of the tower. How long does the clock
  86. physics

    It is the year 2305 and the tallest structure in the world has an insane height of 3.19×106 m above the surface of the Earth. A pendulum clock that keeps perfect time on the surface of the Earth is placed at the top of the tower. How long does the clock
  87. critical thinking

    When the interests of politicians or big business moguls coincide with those of the masses which of the following is the consequence? Answer coverage of events will be slanted coverage of events will be automatic coverage of events will be cancelled
  88. science help PLS

    Which of the following correctly describes a way in which Earth’s atmosphere interacts with the hydrosphere? Living organisms breathe gases in the atmosphere. Water moves between Earth’s surface and the atmosphere. Gases in the atmosphere trap incoming
  89. science

    ok i have a couple questions. 1. How has life changed throughout Earth's history? 2.What are three things that fossils tell us about earth's past? 3.What is radioactive dating? how do scientists use parent and daughter elements to determine the age of a
  90. Physics

    The wavelength of light emitted from a distant galaxy by a hydrogen atom is observed to be 400 nm. If it is known that the laboratory wavelength of this light emitted by hydrogen is 380 nm, what is the velocity of the galaxy? (a) .135c away from Earth (b)
  91. Physics

    The distance between earth and the moon can be determined from the time it takes for a laser beam to travel from earth to a reflector on the moon and back. If the round-trip time can be measured to an accuracy of 0.19 of a nanosecond (1 ns = 10-9 s), what
  92. Physics please help!

    The distance between earth and the moon can be determined from the time it takes for a laser beam to travel from earth to a reflector on the moon and back. If the round-trip time can be measured to an accuracy of 0.19 of a nanosecond (1 ns = 10-9 s), what
  93. Physics for Life science

    The planet Jupiter is more than 300 times more massive than Earth. However, an object scarcely weighs 3 times as much on the surface of Jupiter as it does on the surface of the Earth. How can that be? determine the radius of Jupiter in terms of Earth
  94. AP Physics

    At their closest approach, Venus and Earth are 4.2x10^10m apart. The mass of Venus is 4.87x10^24kg, the mass of Earth is 5.97x10^24kg, and G=6.67x10^-11Nm2/kg2. What is the force exerted by Venus on Earth at that point?
  95. Physics

    Consider a spaceship located on the Earth-Moon center line (i.e. a line that intersects the centers of both bodies) such that, at that point, the tugs on the spaceship from each celestial body exactly cancel, leaving the craft literally weightless. Take
  96. Physics

    Assume that Earth’s magnetic field is every- where perpendicular to the path of a proton and that Earth’s magnetic field has an inten- sity of 4.10 × 10−8 T. What speed would a proton need to achieve in order to circle Earth 1170.0 km above the
  97. physical science,

    the planet jupiter is more than 300 times more massive than earth. However,an object scarcley weighs 3 times as much on the surface of jupiter as it does on the surface of the earth. how can that be? Determine the radius of jupiter in terms of earth radii
  98. Astronomy

    Imagine that Earth did not turn on its axis. (a) What would be true about the ecliptic? It would now define the day rather than the year. It would still be defined and could be seen from all points on Earth, but only when they faced the sun. It would still
  99. Physics repost please clarify

    The distance between earth and the moon can be determined from the time it takes for a laser beam to travel from earth to a reflector on the moon and back. If the round-trip time can be measured to an accuracy of 0.19 of a nanosecond (1 ns = 10-9 s), what
  100. electric physics

    Near Earth, the density of protons in the solar wind (a stream of particles from the Sun) is 12.4 cm-3, and their speed is 576 km/s. (a) Find the current density of these protons. (b) If Earth's magnetic field did not deflect the protons, what total