Planet Definition and 812 Threads

Homework Statement Planet Z is 5000 km in diameter. The free-fall acceleration on Planet Z is 7.00 m/s^2. What is the mass of Planet Z? Homework Equations Well Newton's gravitational law G(M1M2)/R^2 And I cannot think of much else The Attempt at a Solution On one of the...

Alright, I'm not really a physics major or a scientist, but I do have a basic understanding of physics. In fact, I'm actually a writer and right now I'm trying to research the physics of what this thread is titled as, a metal planet. Problem is since I'm not a physics major or scientist, I sort...

Homework Statement Planet X rotates in the same manner as the earth, around an axis through its north and south poles, and is perfectly spherical. An astronaut who weighs 950.0 N on the Earth weighs 919.0 N at the north pole of Planet X and only 855.0 N at its equator. The distance from the...

Homework Statement A planet of mass m orbiting the Sun(mass=m_s along an elliptical orbit, with aphelion r1 and perihelion r2. Find the angular momentum of the planet relative to the centre of the Sun. Homework Equations Angular momentum, M=m(R\times v)=mvR sin\theta Distance from Sun...

I've been struggling with this problem for over two hours...PLEASE HELP! Homework Statement A huge cannon is assembled on an airless planet. The planet has a radius of 5.0 \times 10^{6}\;{\rm m} and a mass of 2.6 \times 10^{24}\;{\rm kg}. The cannon fires a projectile straight up at 3800...

Hi Everyone, My teacher gave me a project to created anything that need not to be build out physically. I gave the tittle green planet. So the idea is that one could create a VACUUM tunnel from the north to south pole (or any 2 points that is a diameter of the earth) and a "vehicle"...

Planet X orbits the star Alpha with a 'year' that is 200 Earth days long. Planet Y circles Alpha at nine times the distance of planet X. How long is a year on planet Y? I know that I have to use the kepler's law : T^2 = (4pi^2/GM)r^3 but I'm not too sure how to do solve this... Please...

Homework Statement Consider a planet of radius 7.31 x 10^6 m with a rotation period of 25.4 hours. Compute the radial acceleration of a point on the surface of the planet at the equator owing to its rotation about its axis. Homework Equations T = [2(pi)r]/v a_r = -[(v^2)/r] The...

Homework Statement An astronaut on a strange planet finds that she can jump a maximum horizontal distance of 10.0 m if her initial speed is 2.40 m/s. Homework Equations What is the free-fall acceleration on the planet? (Ignore air resistance.) The Attempt at a Solution So in order to...

Homework Statement An astronaut weighs 672 N on the Earth. What is her weight on planet X, which has a radius Rx = Rearth / 2.00 and a mass Mx = Mearth/9.00? I know that the radius of Planet X is 3189.05 and that the mass of Planet X is 6.638x10^23 Homework Equations so i know that i...

Homework Statement Find the acceleration of gravity within the mantle (at some radius R) of a planet that has a core and a mantle, each with different constant density. Rp= radius of planet Rc= radius of core Pm= density of the mantle Pc= density of the core P= density I know what...

Would there be subtle differences or large differences on how a human or any other living creature grows up from childhood to adulthood into old age if that person were raised on a planet like Earth vs. a place like Jupiter or the moon? In other words , would the transitions from childhood to...

Ok I remeber a question on my physics test. where there's a planet orbiting a star in some other solar system. heres what was given to me. the radius,and the time it took for it to finish 1 revolution. I was asked to find the mass of the sun, that the planet was orbiting around so here's what...

Mars travels in a nearly circular orbit of radius 2.28 x 10^11 m around the Sun. The mass o Mars is 6.27 x 10^23 kg. The gravitational force of attraction between Mars and the sun has a magnitude of 1.63 x 10^21 N. a) what is the speed of Mars? i got 2.4 x 10^4 m/s b)Determine the period...

Homework Statement While visiting Planet Physics, you toss a rock straight up at 13m/s and catch it 2.7s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 210min . What is the mass and radius of the planet Physics? Homework...

Homework Statement When venturing forth on Planet X, you throw a 5.24kg rock upward at 13.0 m/s and find that it returns to the same level 1.51 s later. What does the rock weigh on Planet X? Homework Equations W=m*a The Attempt at a Solution To find the acceleration i good the...

Hi, A dwarf planet discovered in 2005 has now got a name, http://www.sciencedaily.com/releases/2008/09/080918234427.htm how many more do you think are out there? I am betting a lot. Utwig

Hi, I’m new to the forum, having joined after 6 pints on Saturday night while looking for historical evidence of the mythical 10th planet as described by the ancient Sumerians. The purpose of this post is to spark debate, hopefully backed up with facts that can be verified (and I don’t...

This question has been stumping me on my Astronomy homework for the past couple of days. I've tried to input the question into any of the other formulae that we've studied, but I keep drawing a blank on it. Homework Statement Given the size of Triton's orbit(a = 355,000,000 meters) and...

Ever wondered about just how small Earth is? Well here is a quick documentary i made showing just how tiny Earth is. Planet Earth Is Tiny - Video Feedback is most welcome. This sort of puts things in perspective. http://www.future-films.org"

A small planet has an orbital period that is twice that of Earth. What is the planet's orbital distance? From Kepler's 3rd law of planetary motion, I can assume that: rp3 / rE3 = Tp2 / TE2 where rp is the orbital radius of the planet and Tp is the orbital period of the planet...

How does the planet Earth exist? can you please give me a lead on where should I start on this topic? what are the aspects why Earth exists? thank you.

Homework Statement A satellite is in orbit very close to the surface of a spherical planet. The orbital period is 2.58 hours. What is the density of the planet? Assume the planet has a uniform density. Homework Equations T^2=(4pi^2/GM)*r^3 Density=m*v The Attempt at a Solution...

Homework Statement At perihelion a planet in another solary system is 175 x 10 ^ 6km from its Sun and is traveling at 40km/s. At aphelion it 250 x 10 ^ 6 km distant and is traveling at? Homework Equations IiWi = IfWf The Attempt at a Solution What do i do?

Homework Statement The mass of a hypothetical planet is 1/100 that of Earth and its radius is 1/4 that of Earth. If a person weighs 150 lb on earth, what would he weigh on this planet Homework Equations I think F = G*m1*m2 / r^2 The Attempt at a Solution I believe F = 150lbs (im...

Well, I thought I would start walking to the nearby stores instead of using the car to be more "environmentally friendly" and get some excersize at the same time. Turns out that walking is bad for the environment because the extra food consumed to offset the lost calories is worse for the...

Homework Statement planet with mass m and uniform density and radius r, show by integration that the force this body generates on say a satelite is equivalent to a point mass m at the center of the planet Homework Equations i know that gravitational pull is inversley to r*r The...

When our star the Sun finally accumulated enough matter for fusion to start what would that have done to the planets around it? Afterward what would have happened to the Earth for it to get from when the sun started fusion and blasted the Earth and now, with water and atmosphere?

has anyone ever done research on the accretion of planets into a system without a star forming? Just a dark system. How likely is this to happen as opposed to a system forming with a star?

The fastest rate of rotation of a planet is that for which the gravitational force on matter at the equator just provides the centripetal force necessary for that matter to move with circular motion. Show that the period of rotation in this case is given by T= √3π/Gp where the planet is...

http://www.reuters.com/article/lifestyleMolt/idUST29336420080514 What will they think of next?

The dense atmosphere on the planet Venus makes Venus the hottest planet in the solar system, even hotter than Mercury the closest planet to the Sun. suggest an explanation for this anomaly that involves the electromagnetic spectrum. - Electromagnetic waves travel slower in denser mediums, and...

Homework Statement a planet is 2.00 a.u. when it is closest to the sun. its eccentricity is .5000. Find its period in years. Homework Equations The Attempt at a Solution i got this so far... don't know if it is right PD + AD = A -AD - PD = F <SUBTRACTING THESE TWO>...

[SOLVED] Density of a planet using orbit of a satellite Homework Statement A satellite is in a circular orbit about a planet of radius R. If the altitude of the satellite is h and its period is T, show that the density of the planet is \rho=\frac{3\pi}{GT^2}(1+\frac{h}{R})^3 The...

The planet is doomed, how do you make sure you get one of the limited seats to the new planet. A person who knows how to smelt iron may be chosen over one that knows how to split atoms, and a person who can build a wind mill may be chosen over one that can build a computer, but then who knows.

A long time ago, Galileo stated the vertical motion of a falling body is not influenced by its horizontal motion. Is that still true in moderns terms, taking relativity into account? For example, if a particle is fired horizontally at 0.8c, will it hit the ground at the same time as a...

Hi, I want to confirm this: a=8, b=5, c=7 Count out the distance from origo to planet z = ax + by + c in three different ways. 1) With the aid of linear algebra and geometry (no derivates!). Normalvector is: (a,b,-1) , the length * (8,5,1) = p ,(p=point) p=(x,y,z) gives 8s=x ...

Over 200 planets have been discovered by the radial velocity technique. Why no black holes? For similar periods, the signal amplitude should be much greater. TIA. Jim Graber

Homework Statement The path of a very small satellite S in an elliptical orbit around a massive spherical planet P is shown in the figure. The distance from 3 to 4 is the same as from 4 to 5, 9 to 10, and 10 to 11. (Select T-True, F-False, G-Greater than, L-Less than, E-Equal to, If the first...

Homework Statement You have been visiting a distant planet. Your measurements have determined that the planet's mass is twice that of Earth but the free-fall acceleration at the surface is only one-fourth as large. Radius = 1.8*10^7meters Mass = 1.19484 × 10^25 kilograms Homework...

:rolleyes: I've been wondering about the Earth's age. Some says...1000000000000 or what..? other says..almost 7000 years or 6000+..Well, what do you think?

Is the spectrum of reflected light of a planet the same as the spectrum of the star near it but just less in magnitude? Like when you do B(Lambda;T) for it you just multiply that answer by the albedo?

The Earth moves around the sun in a nearly circular orbit of 1.50 x 10m ^ 11 During the three summer months (an elasped time of 7.89 x 10s^6) the Earth moves 1/4 the distance around the sun. What is the average speed of the Earth?

Sorry if this is in the wrong part of the forum but I am a budding SciFi authro with many ideas. And I just wanted to check if one of my ideas is possible, and if not, how this effect could be best recreated. I'm sure everyone has seen the Star Wars movies. Well if you remeber Star Wars...

if the angular momentum of planet is constant when its orbiting around the sun then velocity X radius is a constant vr=constant but if we consider the velocity and distance from the sun of the planet in an elipticall orbit to be v and r the centrepital force is provided by gravitational...

Homework Statement An extra solar planet is discovered that is 500 light-years away. It is found through spectroscopic analysis that the abundance of potassium - 40 to potassium - 39 on the planet is 99.9%. Assuming that the planet was created with equal amounts of the two potassium isotopes...

Homework Statement A planet similar to the Earth has a radius 4.4*10^6m and has an acceleration of gravity of 10 m/s^2 on the planet's surface.The planet rotates about its axis with a period of 25h. Imagine that the rotational speed can be increased. a/If an object at the equator is to have...

When I was in college years ago, I came across this test question: How will the periodic table of elements look like in another planet? Perhaps, it is asking for a general answer. Do you know if it will change the order of the elements?

Homework Statement >>the time separating high tides is 12 hours and 25 minutes. if high tide occurs at 2:10 P.M. one afternoon: Homework Equations >>when would you expect low tides to occur the next day? The Attempt at a Solution Tide is caused by gravity of moon. High tide means is...

[SOLVED] radius of synchronous satellite from a planet Homework Statement A "synchronous" satellite, which always remains above the same point on a planet's equator, is put in orbit about a planet similar to Jupiter. This planet rotates once every 7.8h, has a mass of 1.8e27kg and a radius of...