1. science

    in a hydrogen atom an electron of mass 9.1*10^-31 kg revolves about a proton in a circular orbit of radius 53 ampere .calculate the centripetal acceleration electron on charge 1.6*10^-19
  2. physic

    A particle of mass 10kg Move in a circular orbit of ratio 2cm with a linear velocity of 0.2m/s calculate the angular velocity, the frequency and the centripetal force
  3. Physics

    Consider classical electron orbit with radius 53pm (picometers) that has a magnetic moment equal to sqrt(2)*μB (the Bohr magneton). What is the current of that orbiting electron in A?
  4. physics

    Consider classical electron orbit with radius 53pm (picometers) that has a magnetic moment equal to 2μB (the Bohr magneton). What is the current of that orbiting electron in A?
  5. physics

    The sun’s mass is about 2.7 x 107 times greater than the moon’s mass. The sun is about 400 times farther from Earth than the moon. How does the gravitational force exerted on Earth by the sun compare with the gravitational force exerted on Earth by the moon? Amoon = g* ...
  6. Physics

    What provides the centripetal force : i)on the elctron orbiting the proton in a hydrogen atom ii)satellite orbiting the planet iii)on the child being whirled round in a chair on the end of a chain in the fairground ride ? Ayuada por favorr :)
  7. Astronomy - Physics

    Finally, we will look at a system that is in an orbit comparable to the Earth to see how the angle that the light strikes the surface and the length of day contribute to the total amount of energy that we receive from the Sun at the two solstices. Recall that the changing ...
  8. Geometry

    The radius of Jupiter is approximately 44,423 miles, and the radius of the Earth is approximately 3,960 miles. How many times larger is the volume of Jupiter than the volume of the Earth? Round your answer to the nearest whole number.
  9. physics

    Suppose that 7.40 g of hydrogen is separated into electrons and protons. Suppose also that the protons are placed at the Earth's north pole and the electrons are placed at the south pole. What is the resulting compressional force on the Earth?
  10. math

    An object that weighs about 2.1 pounds on the moon weighed 12.56 pounds on Earth. About how much would an astronaut who weighs 174 pounds on Earth weigh on the moon?
  11. physics

    Earth of mass 6×10^24 kg is in motion around the sun with a linear velocity of magnitude 30 km/s. a) Determine the magnitude of the linear momentum of the center of mass of Earth. b) Is this linear momentum conseved?
  12. grammar

    I have learning how prepare for an effective meeting. For an effective meeting you must invite a neutral facilter to sensitive meeting, only hold a meeting if necessary , an meeting must have clear objectives , all meeting have an agenda which includes: topic for discussion , ...
  13. grammar

    I have learning how prepare for an effective meeting. For an effective meeting you must invite a neutral facilter to sensitive meeting, only hold a meeting if necessary , an meeting must have clear objectives , all meeting have an agenda which includes: topic for discussion , ...
  14. physics

    A canoe has a velocity of 0.490 southeast relative to the earth. The canoe is on a river that is flowing at 0.520 east relative to the earth creating a 45 degree angel between the two velocities.Find the magnitude of the velocity of the canoe relative to the river.
  15. Velocity

    Which of these statements are true... I think (1)and (5) are correct 1)A reversing vehicle must have negative velocity 2) A stationary object must have zero position 3)Two vehicles trvelling at the same speed at the same instant of time on the same road must have the same ...
  16. Physics: fictitious forces

    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 39.0° north latitude? Assume that the Earth is spherical. This was in my textbook with an angle of 35 instead of 39 and the...
  17. Physics, fluid mechanics

    The temperature of earth atmosphere drops 5°C for every 1km elevation above the earth surface. If the air temperature at ground level is 15°C and 760 mmHg, determine the elevation in m when the pressure is 380 mmHg. Assume the air is an ideal gas with molecular weight of 29 ...
  18. physics

    calculate the escape velocity for the following; assume a launch from the surface. A space probe leaving the moon to come back to Earth. A moon mission lander leaving the moon to come back to Earth. A spaceship leaving the solar system.
  19. Physics

    A canoe has a velocity of 0.490 m/s, 45 degrees southeast relative to the earth. The canoe is on a river that is flowing at 0.600 m/s east relative to the earth. Find the magnitude of the velocity vector v of the canoe relative to the river. Express your answer in meters per ...
  20. Thomas Malthus

    Thomas Malthus was a clergyman so is it safe to say that he did not believe in anything opposing the bible? Is it safe to say that as a firm believer in faith, he was certain that God created the Earth and the life on it? What can i say about Malthus's views on the Earth's ...
  21. college physics

    An object thrown vertically upward with initial velocity from the surface of the Earth reaches a height H before falling back toward the Earth. If initial velocity is doubled, the object reaches a maximum height equal to ________. Ignore air resistance.
  22. earth

    #16 the inner core of the earth is solid because of increased__________ a> density and composition b> density and temperature c> temperature and pressure d> pressure and density
  23. math

    Earth weight is 5.9736 x 10^24 Kg and Venus is 4.8685 x 10^24 Kg. What is the combined weight of Earth and Venus ? a)10.8421 X 10^26 Kg b)10.8421 x 10^23 Kg c)10.8421 x 10^25 Kg d)1.08421 x 10^25 Kg
  24. Math

    Earth weight is 5.9736 x 10^24 Kg and Venus is 4.8685 x 10^24 Kg. What is the combined weight of Earth and Venus ? a)10.8421 X 10^26 Kg b)10.8421 x 10^23 Kg c)10.8421 x 10^25 Kg d)1.08421 x 10^25 Kg
  25. physics

    Using Newton's Law of Universal Gravitation, compare the effect of the Sun and the Moon on the tides. Constants: Mass of the Moon, M☽= 7.348E22 kg. Moon's semi-major axis, a☽= 3.844E8 m. You can find the other constants you will need on the Astronomy Formula Chart...
  26. Media and Culture

    Discuss the similarities and difference between cable communication and traditional television broadcasting. and include the future role of broadcast TV in the face of growing cable and dir3ect broadcast satellite use.
  27. Phizzics....

    How does the weight of a Mars lander change as it travels from Earth to Mars? Does the weight ever equal zero? Does the mass of the lander change? Explain your answer. (Hint: restrict your analysis to a system consisting of Earth, Mars and lander.)
  28. Physics (Fill in the Blanks)

    1. The last stage of a giant star is ____ 2. The path of a satellite is called ____ 3. The size of the Sun is the result of the "tug of war" between two opposing processes, nuclear fusion and ____ contraction Thanks :)
  29. Astronomy

    For this question assume the moon is 110 of its diameter away from the Earth. The largest apparent size of Mercury that we ever see in the sky is 1/150 the apparent diameter of the Moon. The diameter of Mercury is about 4900 km. What is the closest that the Earth and Mercury ...
  30. Astronomy - help!

    The earliest fossil records indicate that life appeared on Earth about a billion years after the formation of the solar system. What is the most mass that a star could have in order that its life-time on the main-sequence is long enough to permit life to form on one or more of...
  31. physics

    Which one of the following statements describes the condition(s) for which a rigid body is in equilibrium? Only internal forces can be present. The sum of the externally applied forces must be zero, and the sum of the externally applied torques must be zero. Each external ...
  32. algebra

    Beginning with cars made in 1981, all vehicles must contain a 17-digit Vehicle Identification Number (VIN). The first 3 positions must be letters or numbers, position 4 and 5 must be letters, positions 6 and 7 must be numbers, position 8 can be a letter or a number, position 9...
  33. business,geographe,life sciences and maths lite

    What career will I study when I finish my matric and how must I pass or how must the levels be like?
  34. English

    Either you must stop eating my food from the refrigerator or you must pay me for it. What sort of conjunction is used in the sentence? common,coordinating,etc
  35. Math

    the mass of earth is 5.97 x 10^24 kilograms. The mass of the moon is 7.34 x 10^22 kilograms. Part A: What is the combined mass of earth and the moon? express your answer in scientific notation. Part B: How many times greater is the mass of earth than the mass of the moon? ...
  36. physics

    if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
  37. physics

    if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
  38. Math

    Mercury's average distance from the sun is 57,910,000 km. The Earth is approximately 93,000,000 miles from the sun What would be the distance of a trip from Mercury to Earth, via the Sun. Look out for the units!!! (1 km =(0.62mi) Use Scientific Notation to solve this question.
  39. science

    why do we celebrate earth day? is it important to celebrate earth day?
  40. science [planets/stars]

    Hey.. Well, first things first.. I'm given an assignment from my Earth Science class. Right now we're doing a unit about planets and Earth and sun. My teacher told us to write a [maximum] 2 page essay, which is also supposed to be descriptive. In the essay, we have to pretend ...
  41. science

    the free-fall acceleration on the surface of the moon is appromimately 1/6 of the free-fall acceleration on the surface of earth. compare the period of a pendumlum on earth with that of an identical pendulum set in motion on the moon
  42. physics help 2 please!!

    Mass A (7 kg) and mass B (10 kg) sit on the ground, 2 m apart. a.) What is size of the the gravitational force: on A from B? N on B from A? N b.) What is the size of the gravitational force: on A from the Earth? N on B from the Earth? N once again, i am using the wrong ...
  43. science

    The atmospheres of Mars and Venus are mostly carbon dioxide. Earth’s atmosphere contains only a fraction of a percent of carbon dioxide. Why is Earth’s atmosphere so different from those of Mars and Venus?
  44. investing 2-2

    If an individual buys stock on margin and its price rises, the investor A. must put up additional collateral. B. must pay tax on the unrealized gain. C. must pay interest on the borrowed funds. D. may take delivery of the stock. I think the answer is C because if you gain or ...
  45. math,algebra

    How do I even write an equation for this problem all i need someone to show me how to get an equation so i can solve it. 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 ...
  46. Statistic

    What must be true in order for P(A OR B)=P(A) +P(B)? a and b cannot be disjoint a and b must be independent a and b cannot be independent a and b must be disjoint it is always true 2. What must be true for P(A and B)=p(A) * P(B) a and b cannot be independent a and b must be ...
  47. Astronomy

    Only one side of the moon is visible from Earth because... A. the moon does not rotate on its axis. B. the moon does not revolve around Earth. C. the moon rotates faster than it revolves. D. the moon revolves once and rotates once in the same period of time. I chose D. Is that...
  48. Math

    I need to justify how a base in a logarithmic function graph is a base. Here are the choices: The graph of f(x)= log_3 x+c must intersect with the line y= c+1 when x= 3. The graph of f(x)= log_3 x+c must intersect with the line y= c when x= 3. The graph of f(x)= log_3 x+c must...
  49. 8th grade science

    explain that gravitational force is the dominant force determining motions in the solar system and in particular keeps the planets in orbit around the sun
  50. Physics

    Suppose an electron was bound to a proton as in the hydrogen atom, but by the gravitational force rather than by the electric force. What would be the radius and energy of the first Bohr orbit?
  51. earth science

    hi im supposed to create a children’s story about Roger the Rock. Roger is a rock that has been a part of the rock cycle for millions of years. Your job is to tell Roger’s story. What volcanoe he came from and where he lived. You must describe how Roger was “born” and ...
  52. Civics

    What must occur for state legislatures to propose an amendment to constitution One-half of state legislatures must vote to propose the amendment Two-thirds of congress must vote to propose the amendment Three-fourths of state legislatures must vote to propose the amendment...
  53. Physics

    At what distance above the surface of the earth is the acceleration due to the earth's gravity 0.790 m/s^2 if the acceleration due to gravity at the surface has magnitude .
  54. Algebra

    The mass of Earth is about 3 × 10-3 times the mass of Jupiter. The mass of Earth is about 6 × 10 24 kg. What is the mass of Jupiter? Give your answer in scientific notation.
  55. physics

    If the sun is 372 times farther from the Earth than the Moon, and the Moon is falling around the earth at 1.4 mm/s, what is the rate that the Sun is "falling?" Is it 1/(372^2) or 7.22*10^-6 mm/s?
  56. Maths

    the speed of light is 3 * 10^ 8m/s. Jupiter is 778 million km from the sun. Calculate the number of minutes it takes for sunlight to reach Jupiter ? A star is 300 lights away from Earth. If the speed of light is 3 * 10^5 km/s. calculate the disatance from the star to Earth. ...
  57. Science

    Geologist believe that The crystals inside a geode probably form when... A: Lava suddenly cools on earth’s surface B: Minerals dissolved in a solution evaporate C: Minerals dissolved in a solution crystallize D: magma cools slowly inside Earth Ok so I’m Almost positive ...
  58. math

    How many five digit numbers can be formed for the set { 0,1,2,3,4,5,6,7,8,9} if zero cannot be the first digit and the given condition for each is to be satisfied? A. Repetitions are allowed and the number must be even. B. Repetitions are allowed and number must be divisible ...
  59. Physics

    I've been stuck on this equation for a while and I don't know if i'm missing a key part to the equation.. i just need help! If the gravitational field strength at the top of Mount Everest is 9.772 N/kg, approximately how tall (in feet) is the mountain? F= g ( m1 x m2)/ radius^...
  60. physics

    i posted this earlier but am now stuck on getting through the algebra 1. The problem statement, all variables and given/known data 13) (II) At what distance from the Earth will a spacecraft on the way to the Moon experiance zero net force due to these two bodies becasue the ...
  61. Physics

    When astronomers find a redshifted celestial object, they say that the object is moving away from Earth. Can the redshift be interpreted as the Earth moving away from the celestial object?
  62. Algebra II

    what value of x makes the following equation true? -5(x + 10)2=390,625 All work must be shown and explantions must be in complete sentences.
  63. Math

    The ocean covers about 71% of the Earth's surface. If the total surface area of the Earth is about 510 million square kilometers, how many square kilometers are covered by the ocean? 362.10
  64. physics

    The weight of an object on the moon is one-sixth of its weight on the Earth. The ratio of the kinetic energy of a body on the Earth moving with speed V to that of the same body moving with speed V on the moon is:
  65. Astronomy

    Light travels at a constant speed of 3.0 x 105km/s. The distance between the Sun and the Earth is about 1.5 x 108km. Use the distance = speed x time formula (d = v t) to calculate the time it takes light to travel from the Sun to the Earth. Show your work. Express your result ...
  66. Astronomy

    Light travels at a constant speed of 3.0 x 105km/s. The distance between the Sun and the Earth is about 1.5 x 108km. Use the distance = speed x time formula (d = v t) to calculate the time it takes light to travel from the Sun to the Earth. Show your work. Express your result ...
  67. physics

    A student of weight 990 N was sent to another planet called Nerdland. If Nerdland has a mass that is three times the mass of the earth and a radius that is half the radius of the earth, what would be the mass in kg of the student when on Nerdland?
  68. physics

    A student of weight 600 N was sent to another planet called Nerdland. If Nerdland has a mass that is three times the mass of the earth and a radius that is half the radius of the earth, what would be the mass in kg of the student when on Nerdland?
  69. phsics

    A student of weight 830 N was sent to another planet called Nerdland. If Nerdland has a mass that is three times the mass of the earth and a radius that is half the radius of the earth, what would be the mass in kg of the student when on Nerdland?
  70. PHYSICS

    A student of weight 830 N was sent to another planet called Nerdland. If Nerdland has a mass that is three times the mass of the earth and a radius that is half the radius of the earth, what would be the mass in kg of the student when on Nerdland?
  71. pronoun (need to make sure)

    Both of the girls must give ____ speeches today. their<----- I chose this one. she her Which sentence corrects the following sentence? The final decision must be made by Ellen and he. A.) The final decision must be made by Ellen and him. <------ I chose this one. B.) The...
  72. English

    I forgot to include a few more sentences I'm not sure of. Thank you. 1) You mustn't modify or change (?) the marks on your school report 2) You mustn't fake (Or counterfeit) your parent's or teacher's signature on your school report or (how do you call a student's register ...
  73. Astronomy help

    I have already solve the problems in many time, but still cannot get the correct answer, can someone kindly help me to solve the problem, please? 1. Suppose the Moon is at a (center-to-center) distance D from Earth. Find an exact expression for the magnitude of the tidal force...
  74. science

    Sarah wants to use a model to get an idea of how far away the stars are. She uses a marble to represent the Earth, and she places a basketball 1 m away to represent the Sun, which is the nearest star. If Sarah wishes to keep the distances between objects in her model at an ...
  75. physics

    An astronaut in full gear has a weight of 2900 N on Earth. Jupiter; weight on planet relative to earth is 2.53 and weight of a 150-lb person is 380. How much will the astronaut weigh on the Jupiter? W_{Jupiter} =________________ N Neptune; weight on planet relative to earth is...
  76. physics-vectors

    If the magnitude of the sum of two vectors is greater than the magnitude of either vector, then: If the magnitude of the sum of two vectors is less than the magnitude of either vector, then: a. the scaler product of the vectors must be negative b. the scaler product of the ...
  77. physicalscience

    1. which one of the 4 keeps electrons in orbit around the nucleus? electromagnetic force weak force strong force gravity 2. which is the greatest of the 4 fources
  78. Physics

    Spaceman Fred orbits planet X with his spaceship. To remain in orbit at 410km from the planet's center, he should maintain a speed of 68 m/s. What is the mass of planet X?
  79. Physics

    Spaceman Spiff orbits planet X with his spaceship. To remain in orbit at 410km from the planet's center, he should maintain a speed of 68 m/s. What is the mass of planet X?
  80. i really need help and i dont ask alot so plzz

    I NEED HELP WITH THIS its a TEST: 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 destructive forces gravitational ...
  81. Physics- Final exam help

    A proton with kinetic energy 100 keV is moving in a plane perpindicular to a uniform magnetic field of magnitude 2.3 T. Find the radius of its orbit. Not sure what equation to use or how to solve.
  82. Algebra-Check my answer please!

    The Great Galaxy in Andromeda is about 2200000 light years from Earth. Light travels 5900000000000 miles in a year. How many miles is the Great Galaxy in Andromeda from Earth? I got 1.298* 10^20 miles. (This is the exponents unit)
  83. physics

    During an Apollo lunar landing mission, the command module continued to orbit the Moon at an altitude of about 165 km. How long did it take to go around the Moon once?
  84. 11th grade

    In the Bohr model of the hydrogen atom, the speed of the electron is approximately 2.17 x 10^6 m/s. find the central force acting on the electron as it revolves in a circular orbit of radius 5.42 x 10^-11m.
  85. physics

    During an Apollo lunar landing mission, the command module continued to orbit the Moon at an altitude of about 113 km. How long did it take to go around the Moon once?
  86. Science

    1.)Which of the following terms refers to an object that orbits the sun and has enough gravity to be spherical but has not cleared the area of its orbit? (1 point) A.)comet B.)asteroid C.)dwarf planet D.)planet
  87. physics

    During an Apollo lunar landing mission, the command module continued to orbit the Moon at an altitude of about 58.6 km. How long did it take to go around the Moon once, in seconds?
  88. Language Arts

    Which sentence correctly uses pronouns? A. If people want to succeed in life, they must know the rules of the game. B. If someone wants to succeed in life, we must know the rules of the game. C. If a person wants to succeed in life, you must know the rules of the game. D. If ...
  89. Language Arts

    Which sentence correctly uses pronouns? A. If people want to succeed in life, they must know the rules of the game. B. If someone wants to succeed in life, we must know the rules of the game. C. If a person wants to succeed in life, you must know the rules of the game. D. If ...
  90. Physics

    Suppose a cylindrical platform with moment of inertia 0.005kg m2 is freely rotating at angular speed 10 rad/s. A disc initially, rotationally at rest with mass 0.6kg and radius 0.1 m is dropped onto the platform so that their centers coincide. The kinetic frictional ...
  91. science

    The atmosphere is composed of a mixture of _______________, _____________ ____________, and tiny___________________. Thank you for using the Jiskha Homework Help Forum. The origin of our atmosphere is still open to a great deal of speculation. One theory is that the first ...
  92. physics

    What is the speed of a communications satellite orbiting the Moon at an altitude of 290 km above the Moon’s surface? I know that G=6.67e-11 and h=290. I plugged inthese values, 7.35e24 for the mass and 1.738e6 for the radius into v=sqrtGM/R=h but I didn't get the right answer.
  93. Physics

    a 1000 kg space craft at 500 m/s is on a collision course with a 400 kg satellite travelling at 700 m/s . Their paths are converging at a 45 degree angle . After the collision they remain locked together. What is the final speed of both satellites? What angle is this at
  94. chemistry

    "Suppose you had a mole of gold atoms (radius=144pm) and could link the atoms together like a string of pearls. How many of these gold necklaces could you make using 1 mole of gold atoms so that each necklace would stretch from the earth to the sun? (Distance from earth to the...
  95. Calculus

    The gravitational force, F, on a rocket at a distance, r, from the center of the earth is given by F=k/r^2 where k = 10^13 newton • km2. When the rocket is 10^4 km from the center of the earth, it is moving away at 0.2 km/sec. How fast is the gravitational force changing at ...
  96. physics

    A 5.0 gm marble is fired vertically upward using a spring gun. The spring must be compressed 8 cm if the marble is to just reach a target 20 m above the marble’s position on the compressed spring .(a) What is the change in the gravitational potential energy of the marble-...
  97. math

    Tina solved for the decimal value 0f (3/5*18) and got an answer of 5.4. Four of her classmates argued that her answer was not reasonable. Which of the following statements best explain why that value can not =5.4 A. the number 18 is a multiple of 3 , so the answer must be a ...
  98. physics

    a spaceship is moving at 1000 m/s release a satellite of mass 1000 kg at a speed of 10 000 m/s. what is the mass of the spaceship if it slows down to a velocity of 910 m/s?
  99. physics

    a spaceship is moving at 1000 m/s release a satellite of mass 1000 kg at a speed of 10 000 m/s. what is the mass of the spaceship if it slows down to a velocity of 910 m/s?
  100. math

    THE DISTANCE FROM EARTH TO MOON IS ABOUT 22^4 MILES . THE DISTANCE FROM EARTH TO NEPTUNE IS ABOUT 22^7 MILES . WHICH DISTANCE IS GREATER ? ABOUT HOW MANY TIMES GREAT ?
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