Sun Definition and 1000 Threads

  1. S

    How do you find the mass of the Sun using data about planet periods and radii?

    How do find the mass of the Sun using the following data: Planet r ... T Mercury 57.9... 0.241 Venus 108... 0.615 Earth 150... 1 Mars 228... 1.88 Jupiter 778 ... 11.9 Saturn 1,430... 29.5 Uranus 2,870... 84 Neptune 4,500... 165 Pluto...
  2. Y

    Coriolis from our orbit around the Sun

    Can we detect any coriolis forces induced from our circular orbit around the Sun ? We're going in a big circle so we should be able to detect some coriolis if we deviate from that circle - ie if we move around a bit instead of following a perfect circular path. Considering the Earth is...
  3. P

    Why doesn't the Earth collide with the Sun?

    I am in AP Physics and we just got done with Centripetal force and Universal Gravitation. I was wondering since for the planets to stay in motion they need to have the same force as the object they are orbiting around. Since a bigger mass means a bigger force, how does the Earth stay in motion...
  4. H

    Earth's Movement and Atmosphere with a Black Hole Sun

    please help me to answer to this problem: Problem: Imagine that we replace sun with a black-hole of same mass. 1. How would be movement of earth? 2. Does the atmosphere of Earth change? If yes, explain. thnx
  5. M

    Finding the Temp of the Sun given only 3 variables.

    Homework Statement This is for my Optics class: Given the radius of our planet, its temperature, and the distance to the Sun, estimate the temperature of the Sun (hint: use the Stephan-Boltzmann law). Homework Equations Radius of Earth \widetilde{=} 6,378.1 km Temperature of the...
  6. Spinnor

    Energy and momentum flux in the sun and Newton's 3rd law.

    Newton's Third Law of Motion: III. For every action there is an equal and opposite reaction. Photons in the sun on average travel outward, electrons and ions on average recoil inwards? Does Newton's third law come into play here? Thank you for help with my confusion.
  7. Spinnor

    A god switchs off the nuclear fires in our sun tonight, do I have to worry?

    Say a god got mad and could and did turn off the nuclear fires in our sun. About how long till Earth freezes? We read that it takes an incredibly long to for the average photon produced in near the center of the sun until the time it scatters for the last time and leaves the sun, does that...
  8. Spinnor

    Energy flux in sun gives rise to polarization of plasma in sun?

    In the energy producing region of the sun there is a large radial flux of high energy photons. Does this outward flux polarize the plasma and give rise to a electric field in this inner region? What is an order of magnitude estimate of this field? As the sun rotates this field gives rise to a...
  9. C

    Radial Acceleration and Gravitational Force of the Sun in the Milky Way Galaxy

    Homework Statement The Milky Way galaxy (including the sun) rotates about its center with a period of 200 million years. The sun is approx. 2 X 10^20m from the center of the galaxy. What is: A) The radial acceleration of the sun? B) What is the net gravitational force on the Sun due to other...
  10. J

    How Many Photons Does the Sun Emit Daily?

    Homework Statement The sun emits 3x1032J of energy every day. Assume it emits only yellow light (6x10-7m wavelength. a. What is the energy of each photon of yellow light? b. How many photons does the sun emit every day? Homework Equations E = hf The Attempt at a Solution So I think...
  11. C

    Some quesitons about Sun and Earh

    1) What keeps the Earth orbiting around the Sun? I know that gravity gives the force of the Earth towards the center of the Sun but what about the tangential force? What gives the Earth the tangential force? 2) What force makes the Earth spin?
  12. L

    Is there something that Sun actually absorbs?

    So is there? :) ... Is there anything (radiation waves, particles, what not...) That Sun absorbs more than it emits? I guess it absorbs visible light of stars behind it, but it emits a ton of more. But is that the case with all EM frequencies? What about gamma rays or any other background...
  13. S

    Find the distance from the sun to the planet known the orbital period problem

    Homework Statement the problem asks to find the distance from the sun to a planet. the only information the question gives the the orbital period of 27 years and asks for the answer in km. Homework Equations c= (2)(pi)(r) The Attempt at a Solution assuming the planet revolves...
  14. 1

    Calculating Earth's Speed Around the Sun

    Homework Statement The Earth travels around the sun in a circle of radius 150 million km and does a complete cycle in about 365 days. Find its speed. Homework Equations v= d/t The Attempt at a Solution d = 1000m/1km x 150,000,000km = 1.5 x 10^11m There are 31,536,000 seconds in 1year. v =...
  15. G

    Angle of the Sun above orbit plane on satellite-centered celestial sphere

    I'm trying to show that for certain combinations of altitude and inclination there will be periods of the year where a satellite has eclipse-free orbits. Using a satellite-centered celestial coordinate system, in which the orbit plane is the equator and the direction of Earth is fixed along the...
  16. W

    I can't understand why the sun moves across the ecliptic

    I can't understand why the sun moves across the ecliptic :( I've been searching for hours and I've found nothing more than "because of the Earth's revolution around the sun", so I'm assuming this is extremely obvious - but I can't understand it. I understand why the declination angle of the...
  17. R

    Are there any objects between Mercury and the Sun?

    Could there be objects between Mercury and the Sun? Like, say, asteroids?
  18. W

    New paper in GRL confirms link between sun and clouds on global scale

    The major conclusion: “A link between the Sun, cosmic rays, aerosols, and liquid-water clouds appears to exist on a global scale…” http://docs.google.com/gview?a=v&q=cache:k3yiHsNVc1cJ:www.wzforum.de/forum2/file.php%3F0,file%3D11877 keep in mind that solar modulation of clouds of even 2-3...
  19. M

    How Does Proton Fusion Sustain the Sun's Energy?

    Homework Statement The sun is powered by fusion, with four protons fusing together to form a helium nucleus (two of the protons turn into neutrons) and, in the process, releasing a large amount of thermal energy. The process happens in several steps, not all at once. In one step, two protons...
  20. N

    Why Don't Heavier Elements Sink to the Sun's Core?

    This website gives a break down of the ten most abundant elements from spectrum analysis of the sun http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/961112a.html" Presumably this result is only valid for the surface/near surface of the sun. If there were any heavier elements present...
  21. Philosophaie

    Magnetic Field of the Sun will Flip

    Magnetic Field of the Sun will Flip I believe some time in November if I am not mistaken. It happens about once every 11 years. I am currently monitoring sites like: http://www.swpc.noaa.gov/SWN/sw_dials.html http://www.srl.caltech.edu/ACE/ASC/DATA/level3/summaries.html To monitor the...
  22. M

    Sun vs. moon - affects on tides.

    In class today, we calculated that the amount of gravity between the sun and the Earth is 180. This is far greater than the amount of gravity beteen the Earth and the moon. So why does the moon affect the tides rather than the sun. My take: the sun is much farther and has a broader pull...
  23. V

    Figuring the location of the sun

    Does anyone know a good way to figure out where the sun is going to be around NYC on a specific day, throughout the day? I need to draw a diagram. I found a handy sun schedule on the U.S. Naval Observatory Astronomical Applications Department website, but I need more specific info than that...
  24. B

    Density of the sun as a white dwarf.

    Homework Statement In about 5 billion years, at the end of its lifetime, our sun will end up as a white dwarf, having about the same mass as it does now, but reduced to about 15,000 km in diameter.What will be its density at that stage? g/cm^3 Homework Equations D=m/v 4/3(3.14)r^3...
  25. D

    Is There a Black Hole at the Center of the Sun?

    In 1916 Schwarzschild wrote down his famous metric to solve (or re-solve using a polar coordinate system) the precession of the perihelion of Mercury. The curvature of spacetime described by the Metric is for any non-rotating spherically symmetric mass. ds^2 = -(1-\frac{2M}{r})dt^2 +...
  26. N

    Electric Potential Earth and Sun?

    Reading about Velikovsky's pseudoscience, I wondered what the values of the Earth and sun's electric potential really are?
  27. Buckethead

    Speedy ship flies through the sun

    If a ship was traveling from afar toward our sun at 99.9999... C and skimmed the outer shell of the sun and continued on, would it burn up? From inside the ship, the trip through the shell might take a billionth or trillionth of a second, hardly enough time for the interior of the ship to heat...
  28. I

    Why does the sun have non uniform distribution of magnetic fields?

    I recall the non uniform distribution of magnetic fields is the reason sun spots occur. Why are sun spots more predominant about the equator as well?
  29. I

    Why does the sun travel faster about its equator?

    Would this be valid for all other planets as well?
  30. S

    How long until the Sun becomes a black dwarf?

    How long after the Sun becomes a white dwarf will it be until it becomes a black dwarf?
  31. M

    Do Planets Orbit Closer to the Sun Over Time?

    Just a quick question Are the planets totaly locked in there orbits forever or do they slowly get drawn in closer to the sun?either by the sun's gravitational pull or simply by the sun expanding? Thanks in advance for any replys mike
  32. P

    Earth's Elliptical Orbit around the Sun

    By just knowing the clues like the force of attraction between two masses and angular momentum conservation principle , linear momentum conservation principle and geometry..can we derive the trajectory of the Earth around the sun is ellipse..if so please tell me your ideas..
  33. Jorrie

    Gaining Orbital Energy from Sun's Gravity-Assist Flyby

    The use of gravity-assist flybys of planets are well known for interplanetary missions. My question: can a Sun flyby be used to gain orbital energy relative to the Galactic center for interstellar missions? I assume one must first attain solar escape velocity by other means, since bound...
  34. V

    Why does the earth and the sun and other planets have gravity?

    This might sound like an unoriginal question but what is gravity? Why does the Earth and the sun and other planets have gravity? Does everything have gravity? What causes gravity? Thanks ahead of time :smile:
  35. A

    Will our sun become black hole if it were moving fast enough?

    Okay, I know that sun won't become BH (Black Hole) , and I know about Chandrasekhar limit and Tolman-Oppenheimer-Volkoff limit, etc. But my question is different. We know, M = m × √(1-v^2/c^2 ) . where m is rest mass. ( Don't know much latex, sorry :frown: ) So now we do know the rest mass...
  36. S

    Solid Angle of the Sun Derivation

    I read in a paper the following passage: "We take the sun to subtend a linear angle of 32 arc-minutes. The solid angle is derived as \Omega=\pi sin^{2}16'=6.8x10^{-5} sr" I don't understand how the formula to go from linear angle to solid angle is just found by taking the area treating...
  37. G

    Gravity at a spot between the Earth and the Sun Summing to 0.

    I had a friend who told me that there is a distance between the Earth and the Sun which the components of gravity add to zero. Is this true? If so, does this mean that something could get stuck there in that spot?
  38. L

    Calculating Earth's # of Rotations Around the Sun

    I'm doing physics of uniform circular motion, while I'm working out this equation It occurred to me , is it possible to find out how many rotations of Earth around the sun until it hits the sun. By the way I'm at a very NOOB level lol but seriously? *thinks of possible equation* :( not...
  39. N

    The intensity of the Sun and heat on Earth

    Hi all. Is the explanation for the fact that it is hotter at equator than other places at the Earth that the intensity of the Suns waves are greater at equator, since the number of beams per area is larger (since they are not scattered that much because of the lack of curvature)? I hope...
  40. M

    Answer: Declination of the Sun - Spring Equinox

    Hi, This might sound like a simple question, but it's not for me. I'm standing at the Tropic of Cancer - what would be the declination of the Sun on the Spring equinox. I believe it should be zero degrees, but my brother says it's 23.5 degrees. Can anybody shed light? Thanks in advance...
  41. I

    How Do the Sun's Layers Differ in Energy Production?

    Homework Statement Using the table that follows, justify dividing the interior of the Sun into two separate functional layers (as regards energy production) and describe the average properties of those two layers.http://img26.imageshack.us/img26/8356/er3z.jpg Homework Equations R/R0...
  42. R

    Gravitational binding energy of the sun?

    Could anyone give me a figure (in joules/kilo joules) for this? Wikipedia says (on it's gravitational binding energy page) that the gravitational binding energy of a star is equal to about two times it's internal thermal energy. I looked for "internal thermal energy" and could not find...
  43. T

    Temperature of a planet a distance from sun

    Homework Statement Hi, A spinning shiny red-appearing planet at 130 billion km from the sun, has a diameter of 1700km. Estimate temperature of planet using simple heat balance equation. Estimate also the temperature obtained by Wien displacement law. Homework Equations I've been...
  44. M

    What is the percentage of heavy element of the sun?

    what is the percentage of heavy element (heavier than helium) of the sun? (not the photospheric composition)
  45. Z

    How was Voyager 2 used to determine the orbits of Uranus and Neptune?

    I am after a reference or an explanation as to how the Voyager 2 spacecraft was used to determine the semi major axis (largest diameter) of the orbits of both Uranus and Neptune? These measurements were performed at Jet Propulsion Laboratory (JPL), NASA, during the Voyager 2 encounter with...
  46. T

    Calculating the Period of a Planet Orbiting the Sun

    Homework Statement A planet moves in an elliptical orbit around the sun. The mass of the sun is M_s. The minimum and maximum distances of the planet from the sun are R_1 and R_2 , respectively. Using Kepler's 3rd law and Newton's law of universal gravitation, find the period of...
  47. U

    Sun Shade Projection type of problem

    Homework Statement Two math students erect a sun shade on the beach. The shade is 1.5 m tall, 2 m wide, and makes an angle of 60° with the ground. What is the area of shade that the students have to sit in at 12 noon (that is, what is the projection of the shade onto the ground)? (Assume the...
  48. U

    Calculating Shade Projection for Beach Sun Shade - Math Homework Solution

    Homework Statement Two math students erect a sun shade on the beach. The shade is 1.5 m tall, 2 m wide, and makes an angle of 60° with the ground. What is the area of shade that the students have to sit in at 12 noon (that is, what is the projection of the shade onto the ground)? (Assume the...
  49. K

    Where Does the Sun's Energy Go?

    as we know "energy can neither be created nor destroyed it can be transferred from one form to another " . so the energy we receive from sun is dissipated here & some amount goes back . so the sun has more energy which gives energy out . so from where does this sun energy goes ??
  50. Z

    Centripetal motion and universal gravitation question: Mars and Sun question

    Homework Statement Mars travels around the Sun in 1.88 (Earth) years, in an approximately circular orbit with a radius of 2.28 x 10^8 km Determine a) the orbital speed of Mars (relative to the Sun) b) the mass of the Sun Homework Equations acceleration centripetal = 4(pi^2)(r) /...
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