Orbit Definition and 1000 Threads

Homework Statement If the eccentricity of a planet's orbit about the sun is 0.4, find (a) the ratio of the lengths of the major to minor axes of the planet's orbit, and (b) the ratio of the speeds of the planet when it is at the ends of the major axis of its elliptical orbit. Homework...

I'm having some trouble understanding this (not a homework question by the way.) A satellite orbits the Earth with a certain angular velocity. Centripetal acceleration is directed radially inward. Acceleration due to gravity of the Earth is also directed radially inward. If I draw a free body...

Homework Statement The weight of a satellite in a circular orbit round the Earth is half of its weight on the surface of the Earth. If the mass of the satellite is 800kg, determine (i)the altitude of the satellite (ii)the speed of the satellite in the orbit (iii)the minimum energy required...

Homework Statement given that T(sun)=5771.4, S(Earth)=1370, D(Earth)=1.5x10^8km, R(sun)=7x10^5km calculate the radiance of solar radiation at Earth orbit Homework Equations Irradiance=Radiance/Solid Angle Solid Angle=Area/Distance^2 I=sigma*T^4 The Attempt at a Solution...

Note: This isn't a HW question. I have learned that the magnitude of charge of a proton and electron is the same (i.e. 1.602 * 10^19 Columbs). Then why does an electron need to move in an orbit because the charges could cancel each other out and the electron could remain stationary. I...

Hello everyone! Please, help me understand the following problem: Homework Statement Earth's orbit around the Sun is nearly circular. The period is 1 yr = 365.25 d. (a) In an elapsed time of 5 d, what is Earth's angular displacement? Solved! (b) What is the change in Earth's velocity, Δv...

I have a problem where it ask to find the period/time(using Kepler's 3rd law) of an unpowered spacecraft to move from Earth's orbit to Mars orbit using the transfer orbit approach. I found P/T using kepler's 3rd law but the second part ask to find how fast the spacecraft need to be moving at...

I'm toying with the idea of making a little 2D space orbiter game so I've implemented Newton's universal gravity law into this little app. It works really well, even. The problem I'm having is when I want to create an asteroid-belt. I spawn little asteroids randomly around an area around the...

I am studying for a modterm on Monday and asking for help on the homework questions I got WRONG on my problem sets (so I can hopefully improve my understanding and see my mistake). This is my reworked version of the incorrect HW problem and I would like to know if I am on the right track...

Hello, I'm doing a project on proving the existence of black holes. I am using Sgr-A as a test subject and am after the data set for the orbit of the star S2 around it so I can do some of my own calculations on it. Does anyone know where i might be able to obtain these?

A.) Assume a rectangular coord system has its origin at the center of an elliptical planetary orbit and that the coord system x-axis lies along the major axis of the ellipse. Show that the equation for the ellipse is given by x^2/a^2 + y^2/b^2 =1. where a and b are the lengths if the...

Hi Everyone! I'm new here and like this forum. Can anyone tell me how the electron moving roundly in atom doesn't emit EM waves while changing it's speed?

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Hy. What makes the planets to keep their position on the orbit (the same orbit). Shouldn't be attracted by the gravitation of the star ? Thanks!

Homework Statement The solar system is situated 26,000 light years from the centre of our galaxy, the Milky Way, and it orbits the centre at a speed of 220 km/sec. Calculate the time required in millions of years for one orbit. (NOTE: The circumference of a circle = 2 pi r where r is...

Homework Statement If someone told you that astronauts are weightless in orbit because they are beyond the pull of gravity, would you accept this statement? Explain. Homework Equations The Attempt at a Solution I say no. There is still gravity, but its just weaker with distance...

Good morning, I have a doubt about the differentiation of the polar equation of an orbit: r=\frac{p}{1+e\cos\nu} It represents the relative position of a planet with respect to the central body. Here, p is the parameter, e is the eccentricity and r is the radius of the planet measured from...

A satellite is in an unstable elliptical orbit around the earth. Is there a way of tracking each satellite's orbit till it reaches the critical stage then follows it's reentry path? V<Vescape r=a*(1-e^2)/(1+e*cos(True Anomaly)) Book recommendations welcome. College educated.

Hello, I was just curious why do all of the planets in the solar system orbit in approximately the same plane? Why is it not random? This is not a homework question, but if possible I would like to see the math that accompanies the explanation. thanks

simple question - can someone please clarify the difference between these two orbits? i recall arthur c clarke's original concept for communication satellites in what i believe he called geosynchronous orbit such that the satellite(s) would remain over a single fixed point on Earth's surface...

What does most evidence point to regarding the reasons for Sedna's looong orbit? I think it highly unlikely that the Sun's gravitation can keep it in place.

Homework Statement Does the centripetal force equal the gravitational force? Homework Equations Fg = G(m1)(m2) / r^2 Fc = 4(pi^2)(m)(r) / T^2 The Attempt at a Solution I have the mass of a satellite in geosynchronous Earth orbit. The period of Earth's orbit, and the Earth's radius and...

what is the maximum number of electrons allowed in each of the first 5 orbits of an atomic particle? Is it the same for all elements? or do different ones hove a different maximum numver of electrons possible of being in an orbit?

http://img810.imageshack.us/img810/1883/planet.jpg Uploaded with ImageShack.us Homework Statement I have a body of mass m, which is moving in a circular path around some planet. At a certain instant, the object explodes into two equal bodies. I'm given that the tangential velocity doesn't...

I've got a pretty simple question, and it may sound dumb, but I'm going to ask it anyway: First, I'll preface by saying that from what I understand (and please verify or correct me), planetary orbit in a star system decays over time a la net force. I also have come to understand that the...

Hello, I’m glad that I found this forum, because there is a question that has been bothering me for some time, and maybe someone on a physics forum like this can set me straight on it. It concerns gravity and acceleration. I understand that when an object such as a space shuttle is...

To reach orbit you have to have your vehicle have a horizontal, i.e., tangential, orbital velocity, of about 7,800 m/s and have sufficient altitude, say at least 100 km, the altitude considered to be "space". To get to this altitude you have to have a separate velocity in the vertical direction...

for ease of explanation, imagine that the barycenter of two planets is the center of a wheel and that the planets revolve around the edges of the tire. the center of the tire (barycenter) is in orbit around sun, as if the wheel is rolling around in its orbit. my question is, is this possible? of...

For the moon to stay in orbit and not crash down into Earth, it must have sufficient tangential velocity. I'm wondering where/how it initially got the energy to reach this tangential velocity. Thanks.

I have a friend who believes that if he spins in a circle he is changing the angular momentum of the Earth and therefore is slowing down the Earth's rotation. Can someone explain exactly why this is not true? To me it is common sense, but I am no physics major. Also, the same friend is...

Saturn takes about 10 years to go around the Sun once. What is the semi-major axis of Saturn's orbit?

If you are in free fall inside a black hole, shouldn't it feel like normal space even though people on Earth saw you enter a black hole?

How is it possible to calculate the force it takes to keep an object in a orbit This is not homework..

Homework Statement A comet in a circular orbit around the Sun has speed v0 and radius r0 = aRE , where RE is the radius of the Earth’s orbit and α is a constant > 1. The comet has its velocity reduced by Δv in a collision that does not change its initial direction. Show that the...

Homework Statement A satellite with a mass of 5.00 x 10^2kg is in a circular orbit, whose radius is 2r_e, around earth. Then it is moved to a circular orbit with a radius of 3r_e. a) Determine the satellite's gravitational potential energy from the first orbit to the second orbit. b)...

I have seen this topic discussed a bit on the web, but I don't see any clear answers. I takes a lot of energy to make the moon go in a curve, if you had to do it with rockets you would need a lot of fuel. Therefore it takes a lot of energy to make the moon go round the Earth for 4 billion...

Hey there, The other day i was solving a simple curvilinear motion problem that used a sattelite in orbit around the Earth as an example and it got me thinking. If a geostationary sattelite is always above the same region of the Earth (and can only occupy an orbit of a certain altitude) it...

I heard that the recent Chile earthquake moved Earth's axis by 8cm or so. Could the Chicxulub asteroid (or the even bigger, Antarctic one I just http://www.dailygalaxy.com/my_weblog/2010/03/did-the-planets-most-massive-asteroid-impact-ever-occur-in-antarctica-nasa-gravity-maps-point-to-yes.html"...

Homework Statement 1) A satellite is in circular orbit around the sun. Which requires the greater change in satellite's speed: to escape the solar system or fall into the sun? 2)Why does atmospheric friction increase the speed of a satellite in low Earth orbit? Homework Equations...

Hello, A question here about Classical Mechanics, Goldstein (Ed. 3) On page 87 you have expression 3.33 which goes something like \[ \frac{1}{r^2}\frac{d}{d\theta}\left(\frac{1}{mr^2}\frac{dr}{d\theta}\right)-\frac{l^2}{mr^3}=f(r) \] I appear to end up with \[...

Homework Statement In a science fiction story, humans have built a large spherical spaceship for an interstellar journey of many generations; they have christened their ship Big Bird. The mass of Big Bird is 7.496×1011 kg (the mass of an aircraft carrier is about 10^8 kg). Most of Big...

I hope someone can help me out here. I am having difficulty understanding what the difference is between the spin orbit interaction and LS coupling scheme in atoms. I know the spin orbit interaction (or spin orbit coupling) is due to the interaction of say an electron's spin with it's orbital...

Homework Statement Given that Jupiter has a mass of 1.9x10^27 kg, and the sun has a mass of 1.99x10^30 kg: a) Calculate the value of Kepler's constant for Jupiter. b) If Jupiter's orbital period is 11.89 Earth years, calculate the average radius of its orbit. Homework Equations K...

I do have a question that bothers me for some days now. I'm not too sure how qualified it is, but my mind needs to be eased here. I understand, that it may be taken as a fact, that BHs cause enough gravity to make photons "vanish" behind the event horizon. So like with any stellar object...

Homework Statement Homework Equations on image The Attempt at a Solution The first thing I did was use the second equation to get Theta dot = L/mr2 Which I then subbed into the first equation to eliminate Theta dot. Now I need everything in terms of r, and this is...

I have a satellite orbit problem I'm not quite understanding...any help would be appreciated. Homework Statement Suppose a spacecraft orbits the moon in a very low, circular orbit, just a few hundred meters above the lunar surface. The moon has a diameter of 3500 km, and the free-fall...

Assuming the expansion of the universe as a given fact, how does it influence orbits i.e. of the Earth around the sun or other planets in the solar system? Is it also usually included into the calculation of trajectories of space crafts (i.e. Pioneer, especially with regard to the Pioneer...

Homework Statement Calculate the formula for the force of gravity in a universe where Kepler's 2nd law holds and a planet revolves around the sun with polar eq r = 1 + sin (theta). Theta = pi/2 is where velocity and position vector are perpendicular. Homework Equations Universal...

What is the radius of a "heliosynchronous" orbit Homework Statement The Sun rotates approximately every 26 days. What is the radius of a "heliosynchronous" orbit, that is an orbit that stays in the same spot of the sun. Homework Equations r = ((GMT^2)/(4pi^2))^1/3 The suns mass is...

According to spin quantum number, the spin value of electron pair is taken as +1/2 and -1/2. Why should we take only these values. I didn't understand what the spin of electron represents.