Sun Definition and 1000 Threads

I have only taken my high school Physics course so excuse me if I don't understand some things right away. I looked at the two stickies and neither seemed to explain my question. I have been trying to understand why the moon's orbit's apogee moves around Earth over a period of time. The...

Homework Statement how many photons does the sun generate to knock one electron across the bandgap in a PV panel? I am doing a college level night school course on Photovoltaics and I have to do a short presentation on photons and how they produce useable energy. I thought it would be...

Sounds a bit crazy. But you have an almost infinite energy supply on tap. Easy to get to as well.

G'day. i'm a 2nd year Aero engineer student from Australia. I've had this question on my mind for the past few days now and can't seem to find much material on it. i was just wondering how the lightest elements (hydrogen and some helium) managed to come together in the center of the solar...

This coursework question I am faced with is very specific and quite difficult to explain so I have attached the question. The writing on the side is not that important so don't try and make sense of it. The question asks to find the angular velocity of 2 planetary gears (which are connected...

Hello, I am trying to revise for my Solar System exam and going through a past paper i have a question relating to something that we don't seem to have covered: "By estimating the energy output of the Sun's corona (in watts), comment on whether can be treated as a blackbody radiator...

Why does the Moon keep the same face toward the Earth but the Earth not keep the same face toward the Sun?

I have a question about the gravitational model used to describe tides: Is it correct to simply add the tide potentials respectively due to Earth and sun as most people do? (see for instance a good example of this approach in Eq 9 of: http://arxiv.org/PS_cache/physics/pdf/0701/0701301v1.pdf)...

Homework Statement What types of energy does the sun produce? Homework Equations N/A The Attempt at a Solution I feel stupid..but I think it produces Light energy as well as Solar Energy? Does it produce Light Energy?

How much more of less would you weigh (same as force) at the surface of the sun than on earth?

I enjoy asking myself random questions and then finding the answers online i.e. forums however, I could not find the answer to this one. What would happen if a gamma ray burst hit a star or specifically our sun?

This is an interesting observation to explain. Nuclear decay rates change depending on the Earth's distance from the sun. The logical conclusion is some solar parameter directly affects the Earth in a manner that affects nuclear decay rates. It is interesting to note that there is a phase...

Are all the frequencies of the Electromagnetic spectrum in a beam of light before being filtered by the Earth's ozone? Beyond ROYGBIV though.. so like infrared rays, microwaves, xrays, etc

Homework Statement Hi everyone, I was wondering if anyone can help me out with my project in physics. Our goal is to make the sun image appear on a panel at the end of a rail, using lens, to see if we can observe sunspots on the projected image of the sun. This is the materials we have...

Homework Statement (a) A certain comet of mass m at its closest approach to the Sun is observed to be at a distance r1 from the center of the Sun, moving with speed v1. At a later time the comet is observed to be at a distance r2 from the center of the Sun, and the angle between rvec2 and the...

Homework Statement Assume the Sun is a uniform, rigid sphere (it is spherically shaped but actually is not of uniform density nor a rigid body). The Sun rotates once every 27 days. (a) Calculate the rotational kinetic energy of the Sun in joules. (b) The luminosity (power output) of the...

Hi all, I looked through the reference library post, but didn't see anything about this. Is there a website that contains the relative locations of the sun, earth, and moon over time? moon phases aside - I would actually like to know the exact locations of the Earth and moon (in say...

Hi everyone my name is Fabien I was wondering is there any accurate way to measure the distance between the Earth and the sun without having some professional materiel. IF yes How accurate are we talking about? How do you do if you want to know precisely? How do the scientist do it? Do you...

Homework Statement Every reaction in the sun has the energy equivalent to 0.03 mp, and generates 2 neutrinos per reaction. Calculate the number of neutrinos per second, and calculate the neutrino flux at Earth. Astronomy generally uses the CGS (centimeter gram second) system, so just be...

Homework Statement Energy from the sun (distance 1.496 x 10^11m from earth) arrives at the Earth at a rate of 1400W/m^2. How fast is the sun losing mass due to energy radiation? Homework Equations The Attempt at a Solution Ok so i thought that Ei = E/r^2 where Ei is incident...

is the distance between the sun and Earth the same as the distance between the moon and the sun?

Homework Statement A camper is trying to start a fire by focusing sunlight onto a piece of paper. The diameter of the sun is 1.39e9 m, and its mean distance from the Earth is 1.50e11 m. The camper is using a converging lens whose focal length is 10.8 cm. (a) What is the area of the sun's...

why is the light from the sun called white light?

How would you go about solving the three body problem in the case of our sun, earth, and moon? The moon's gravitational effects are enough to rule out using the restricted three body problem solution, right? So if given a set of initial conditions, how would one find equations for the...

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I got into an argument with someone over Earth revolving around the sun vs sun revolving around the earth. He stated that there are reference points within the universe where the sun appears to revolve around the Earth that are NOT on the surface of the earth. I conceded that perhaps a point...

Homework Statement Consider the system of the Sun, Earth, and Moon, at a moment in time when they happen to be exactly in a line. (Assume that all distances d are measured between the centers of all bodies, and that all distances d are much greater than the radii of all bodies. M(sun) =...

Hello! I came across this website on my quest to find an answer to this physics problem. I read a topic that was a similar problem, but it didn't address my question in particular. So now I'm posting my problem specifically, and thank you in advance for any help! Homework Statement a. What is...

For this science project I'm doing, i am going to be investigating the I.R Lowpass (a.k.a: Near infrared spectrum) with goggles i shall soon be constructing based on http://www.youtube.com/watch?v=H2-nP2xl9Zg&feature=player_embedded" This question may be a bit silly but will my goggles work...

I understand that the Earth takes 365 days (give or take) to orbit the sun. I also understand that the physics of the universe are in continual flux (expanding universe, cooling suns, etc). Question: Is it plausible to assume that the Earth took a shorter/longer time to orbit the sun a...

Hypothetical question: Imagine that a massive object large enough to observe with a powerful telescope was ejected from the sun and began traveling toward earth. It would take about 8.3 minutes for the light from the sun to reach Earth so we could observe the initial event. Let's imagine...

Homework Statement The Sun rotates about the center of the Milky Way Galaxy at a distance of about 3.00x10^4 light years from the center (1ly= 9.50x10^5 m). If it takes about 200 million years to make one rotation, estimate the mass of our galaxy. Assume the mass distribution of our galaxy...

Homework Statement Ive been trying to find the Inertia and Kinetic energy of the sun. I have a feeling I am using the wrong formulas to obtain the answer. Mass of sun 2*10^30kg Radius of sun 700*10^6 m t spin = 26 days the answers should be I = 4.0 * 10^98 K energy = 1.5 * 10^16 Homework...

hello there let's imagine that the Earth-Moon system became isolated (ie, not subjected to Sun's gravity anymore), would Moon run around the Earth at a lesser speed than now? (if it would, in which proportions then?); and does Moon's orbit would change in circumference?

An asteroid is orbiting around the sun at a distance of 4.2  1011 m. If the Earth orbits around the Sun at a distance of 1.5  1011 m with a period of 3.2  107 s, what is the period of the asteroid?

Homework Statement at a moment of total eclipse the moon lies in a straight line from the Earth to the sun. If your normal weight is 600N how much is your weight decreased by the combined pull of the sun and moon? [b]2. Homework Equations Mass of sun - 2.0x10^30 kg distance from...

Homework Statement A comet passes the sun at a distance of closest approach R = 6 * 10^8 m and speed 8 * 10^5 m/sec. How long will it take to travel 80 degrees around its orbit from the point of closest approach. Homework Equations omega = velocity / radius The Attempt at a...

Homework Statement A comet is in an elliptical orbit around the Sun. Its closest approach to the Sun is a distance of 4.5e10 m (inside the orbit of Mercury), at which point its speed is 9.6e4 m/s. Its farthest distance from the Sun is far beyond the orbit of Pluto. What is its speed when it...

what is "slowness of the sun" in computing azimuth angle? Homework Statement The question is to calculate the azimuth angle for a city and to use the analemma diagram to estimate the "slowness of the sun." Homework Equations The Attempt at a Solution I need to know what slowness...

Pardon this completely naive question. I am wondering why there are net magnetic fields on the Sun. Isn't there an equal number of protons - hydrogen nuclei - to electrons? Is there a separation of protons and electrons in different parts of the Sun so that there can be net currents? or are...

Ok, so the sun appears to move westward on a daily basis. But eastward through the stars on a yearly basis. I am supposed to explain both the daily and yearly motion of the sun using a few paragraphs with definitions and diagrams. For the year I basically have to explain and draw the sun's...

Homework Statement Some values for the Sun are, bolometric luminosity Lbol = 3.83 x 10^26 W, bolometric correction = –0.07, and radius = 6.96 x 105 km. Calculate the visual luminosity, LV, of the Sun and the flux, FV, radiated into space by the solar surface. Homework Equations M1-M2=-2.5...

Reading about the Thermocouple: http://en.wikipedia.org/wiki/Thermocouple I came upon: "... Principle of operation Main article: Seebeck effect In 1821, the German–Estonian physicist Thomas Johann Seebeck discovered that when any conductor is subjected to a thermal gradient, it...

Homework Statement What is the linear velocity of a persion standing at the Earth’s equator with respect to the Sun, when the Sun is just at the Eastern horizon? Homework Equations Not sure, I used to v=d/t to solve for a person's linear velocity at the equator, just not sure how to handle...

Hello! I'm new here, and I don't honestly know anything about astrophysics, so I'm sorry in advance for the upcoming questions and would like to ask you to be as elaborate and as simple as possible. So, if the sun expands, when do you think this will happen? If Earth is still alive, what do you...

Use your average value of G to estimate the mass of the Sun. Assume that the orbit of the Earth around the Sun is circular. The orbital radius of the Earth on its path around the Sun is R=1.5X10^11 m and the Earth needs 365.25 days for one full orbit. You need to provide detailed steps how you...

Homework Statement Phobos is the larger and closer of Mars’s two moons. It has no atmosphere, a mean radius of 11 km, an albedo of 0.07, and an emissivity of 1.0. (i) Assuming that the radiative temperature of Phobos is 222 K and that it is spherical, what is its mean distance from the...

Homework Statement Kelvin could only see the photosphere (the glowing outer surface) of the sun, so didn't know how the mass was distributed inside it. How would the potential energy of the sun change if it was a hollow shell? (No numbers needed; just indicate whether it would be more or...

I was reading something the other day on spectral readings from the sun, and I have a few questions regarding its composition. I know that there are heavier elements (gold, uranium, etc.) in the sun. I'm confused by this, as I didn't think there was enough energy to form such elements. My...