Moon Definition and 1000 Threads

Hi Forum, I am new and have just registered as I have a few quetions I was hoping you may know concerning our moon. At what distance must the moon be from Earth for it to no longer have any gravitational effect on the earth? What is the strength of the moons gravitational effect on...

Anyone around here with imdb account? I thought I would not create an account merely for this one thing, so instead I came complaining here to physicsforums (because I have account here already! :-p) Anyway, somebody should put some comments to the moon goofs feedback...

Tides are created by the gravitational attraction of the sun and moon on Earth. Calculate the net force pulling on Earth during a)New Moon b)Full Moon c)First Quarter Moon. Mass of the Moon: 7.35 x 10^22 kg Mass of the Earth: 5.98 x 10^24 kg Mass of the Sun: 1.99 x 10^30 kg Distance from the...

Homework Statement Two moons orbit a planet in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 5r. Moon A takes 50 days to complete one orbit. How long does it take moon B to complete and orbit? Homework Equations Kepler's Third Law The...

A projectile is launched vertically from the surface of the Moon with an initial speed of 1380 m/s. At what altitude is the projectile's speed two-thirds its initial value? Homework Equations The Attempt at a Solution I don't really know where to start there is so little...

Question: A projectile is launched vertically from the surface of the Moon with an initial speed of 1380 m/s. At what altitude is the projectile's speed two-thirds its initial value? I don't really know where to start there is so little information. We went over escape velocity in class...

Homework Statement A projectile launched vertically from the surface of the Moon rises to an altitude of 370 km. What was the projectiles initial speed? Homework Equations Vf ^2 = Vi^2 + 2ad The Attempt at a Solution distance = 370km x 1000 = 3.7E 5 meters solving for Vi = sqroot...

Homework Statement A projectile launched vertically from the surface of the Moon rises to an altitude of 370 km. What was the projectile's initial speed? Homework Equations h = 370,000 m g moon = 1.62 m/s^2 G = 6.67x10^-11 N m^2/kg^2 Mass moon = 7.35x10^22 kg Radius moon =...

Being not very tech minded I wonder how water (ice) could exist for billions of years in a vacuum without turning to vapor? Ice evaporates at atmospheric pressure on Earth and I guess it is called subliming? Maybe it's because of the super low temps on the moon? Comets are supposed to have lots...

Imagine that we go to the moon, and tie one end of a rope to the surface of the moon, and then take the other end of the rope back to earth. We can't tie it down of course, becuase it would snap as the moon moves away. So instead we make the rope long enough to be a few feet off the ground, and...

I was really excited to learn that NASA had confirmed water on the moon. http://www.nasa.gov/mission_pages/LCROSS/main/prelim_water_results.html"

Is a bicycle ridden with the Moon's gravity less likely to fall over than with Earth's?

Homework Statement Compare the gravitational force on a 9 kg mass at the surface of the Earth (with radius 6.4 × 10^6 m and mass 6 × 10^24 kg) with that on the surface of the Moon (with mass 1 /81.3 ME and radius 0.27 RE ). What is the force on the Earth? Answer in units of N...

Is our moon slowly receding? is it getting further from us? if so why?

Might absence of dust on moon (such as for astronauts' experience) relate to importance of material sciences? That is, might surfaces interact electronically, seeking a more stable lowest energy configuration? Imaging it as if 2 grates rubbing together, seeking best fit? Air might then disrupt...

Homework Statement Somewhere between the Earth and the moon is a point where the gravitational attraction of the Earth is canceled by the gravitational pull of the moon. The mass of the moon is 1/81 that of the earth. How far away from the center of the Earth is this point? a) 8/9 the way...

Homework Statement What is the magnitude of the torque caused by the force of gravity on the moon by the earth? Assume both are spheres of uniform density, the axis of rotation passes through the center of the Earth perpendicular to the plane of the moon's orbit. Earth's mass 5.98 x 10^24 kg...

Homework Statement Two moons orbit a planet in nearly circular orbits. Moon D has orbital radius r, and moon E has orbital radius 4r. Moon D takes 20 days to complete one orbit. How long does it take for moon E to complete one orbit Homework Equations None - I think The Attempt...

Homework Statement Hi guys so i have this problem that i have been trying to solve and i think i might have the right answer but i am a bit confused about something. An astronaut conducting experiments on the moon, drops an object from a height of 1.6m and notices that it takes the...

Homework Statement Given data: A moon of Mars orbits with a period of 459 minutes. The radius of the moon's orbit is 9.4x10^6 m. What is the mass of mars? Homework Equations The Attempt at a Solution The only relevant equation I could find was Fmars on moon= (G*m1*m2)/(r2)...

What are the physical possiblities if the ,astroid Toutatis , crosses directly between the moon and Earth on December 12th 2012. I understand that this is a fairly large astroid and is projected to zoom near Earth somewhere in the range of the distance between Earth and the moon. What are the...

Silly question perhaps but I was thinking.. Shouldn't there in theory be a round light of the moon and then complete blackness around it? Does the light reflect off small particles in the air or something?

Excellent team work amongst NASA and ISRO to confirm the moon does indeed have H20. Well done.

Forget that tired old image of the moon as a entirely dry locale, devoid of any moisture. A recent set of discoveries have found that not only is there water on Earth's sole satellite — but the water is everywhere. Three papers appearing in the upcoming issue of Science Express outline the...

Homework Statement F=GmM/r^2 Homework Equations mass of self=109kg mass of moon=7.36x10^22kg r=384,403,000m gravity of moon=1.63m/s^2 The Attempt at a Solution F=((1.63m/s^2)(109kg)(7.36x10^22kg))/(384,403,000)^3 Am I doing this correctly?

Astronauts spending any significant time on the Moon, and later on trips to Mars, will need to synthesize C6H12O6 and other sachharides for food. Is there any other way then using photosynthesis, using either sunlight or artificial light? Where does most of the CO2 for photosynthesis come from...

Hi, Could someone please crunch for me the de Broglie wavelenght (\lambda), frequency (f) and energy (E) of Earth at perihelion (30300m/s) and at aphelion (29300m/s) and mean (29800m/s) Here are the numbers and formulas: \lambda=h/p , f=E/h , p=m*v (momentum=mass*velocity) h - Planck's...

http://finance.yahoo.com/news/Obama-space-panel-says-moon-apf-2656818175.html?x=0&.v=4 This should be really embarrasing, we spend $3 billion A DAY in Iraq, yet we suddenly won't pay for this? So let me get this straight, he wanted to shut it down only 6 years after the station is...

Even if water ice is not found on the Moon, the fact is that hydrogen and oxygen can be found on the Moon in other forms. How then could could these other materials containing hydrogen and oxygen be processed in bulk, in order to obtain water from them? What would be the most practical way...

Homework Statement You have an object of mass 6.154 kg on the surface of the moon. What force is required to propel the object vertically to a height of 100m? acceleration due to gravity on the moon (g): 1.625 m/s^2 Homework Equations y = (v^2 - v0^2) / (2*g) y: vertical displacement...

If I fill my cup to the brim on Earth the surface of the tea is spherical and concentric with the Earth's centre.It's like a mini ocean of tea.If I do the same thing on the moon my mini ocean of tea has a smaller radius and therefore a larger volume.Discounting evaporation,expansion/contraction...

If a comet kicks the moon, or any celestial object for that matter, out of its orbit and away from the earth, would it alter Earth's rotational axis?

Hello, I am new to this forum and this is my first thread! :) I would like to know how I can compute the Cartestian Coordinates (x,y,z) of the Moon, with the Earth at the origin during the eclipse of August 11 1999 at the time of the greatest eclipse point...

Homework Statement A spaceship is launched and starts moving directly towards the Moon. At what distance from the Earth will the pull of the Moon on the spaceship exceed the pull of the Earth? Ignore the effect of the Sun in this calculation. Homework Equations F = Gm1m2/r2 F = ma...

I hate having to defend the moon landing since so many people disagree with it. The best piece of evidence i can put forward is the mythbusters page debunking the skepticism http://mythbustersresults.com/episode-104-nasa-moon-landing highlight of the page

I saw on t.v. that the moon's distance to Earth as measured by lasers reflecting off of the mirrors left on the moon by Apollo 13 was a bit off from Newton's Fg = Gm1m2 / r^2 formula. I don't recall if the moon was closer or further away from Earth than what was predicted by Newton's formula.

If I was stationary on the Moon looking at Earth, would it never appear to move from its location in the sky? I made a quick model using a tennis ball and a globe and I'm thinking that it would go through "phases" (cresent, full, etc.) as well as spin, but stay in one spot. (which would look...

Recently, there was a http://www.reddit.com/r/space/comments/96iwv/the_year_is_2035_we_have_a_permanent_base_on_the/" on Reddit titled "The year is 2035. We have a permanent base on the moon and have sent multiple teams to Mars and back. What's next for NASA?" There were several interesting...

I ran across this site from 2001: http://www.afineline.org/projects/paint.html Apparently it didn't work very well. Anybody care to guess what kind of equipment it would take to make a red splotch appear on the moon to the naked eye from earth?

When sun puts more gravitational force(numerical values) on moon than earth, then why moon does not revolve around the sun like earth?

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...

A projectile is launched vertically from the surface of the Moon with an initial speed of 1210 m/s. At what altitude is the projectile's speed three-fourths its initial value? can someone please help me with this! i keep getting 1.96x10^5 m but it says that is not the correct answer thanks

is the moon is moving away from us?...or is the universe just expanding? The 'measurement' of the radial expansion of the moon's orbit is 3.8 cm/yr http://curious.astro.cornell.e...uestion.php?number=124 but that measurement is only slightly more than the Hubble constant (the rate that...

...almost to the minute. The precise moment is about six minutes away. I can still remember that day as if it were yesterday. Forty years ago, the world was holding its breath.

http://blogs.discovermagazine.com/badastronomy/2009/07/17/apollo-landing-sites-imaged-by-lro/

There was an article in a German online magazine debunking the theories of moonlanding deniers. One of the issues was revolving around the question why the astronauts didn't seem to reach the heights expected when trying to jump off the ground. The logic: Since moon's gravity is 1/6 of...

The center of mass of the Earth is approximately at the center. The center of mass is also where the force vector of the gravitational force is pointing. (down that is). Now the total gravitational force excerted on me should be the sum of the force excerted by the Earth plus anything else...

I would've thought something like that would be do-able given we've landed on the moon, but also quite useful for discovering more about it.

http://www.phys.ufl.edu/~det/phy2060/heavyboots.html Do you think this is actually true? If so I'm speechless.

I know it's the reflection of the sun light. But why? the moon is full of dirt and rock and how does it give a silvery white glow? A mountain (on earth) with dirt and rock doesn't glow with sunlight reflection. The astronauts who landed on the moon didn't see the moon shiny white.