BMAONE23 wrote:How well does Mass equate with Gravity? If I, weighing roughly 200 lbs, were to be standing on a 5X earth mass super earth planet would i then weigh 1/2 ton?
astrolabe wrote:Maybe the question should be: "What would my diameter be?"
If a 200 lb. BMAONE23 stood on a 5x Earth-mass planet
with the same diameter as Earth, he would weigh 1/2 ton (1000 pounds).
Consider this: Mercury has .055 of the mass of Earth, but divide .055 by the square of the ratio of their radii (divide by .146) to get a surface gravity for Mercury equal to .38 of Earth.
Consider this: Mars has .107 of the mass of the Earth, but divide .107 by the square of the ratio of their radii (divide by .284) to get a surface gravity for Mars equal to .38 of Earth.
Consider this: The ratio of the mass of Mars to the mass of Mercury (1.94:1) is approximately the square of the ratio of the radius of Mars to the radius of Mercury (1.39:1), so force of gravity is about the same on the surface of each.
The force of a planet's gravity on an object at a planet's surface is directly proportional to the planet's mass and inversely proportional to the square of its radius.
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If your 5x Earth-mass planet had the same density as Earth, its radius would be the cube root of 5 (about 1.71) times Earth's radius. So start with 1, multiply by 5, divide by the square of 1.71, and you get a surface gravity of 1.71 times that of Earth. So an object or person weighing 200 lbs. on the surface of Earth weighs 342 pounds on this planet.
[quote="BMAONE23"]How well does Mass equate with Gravity? If I, weighing roughly 200 lbs, were to be standing on a 5X earth mass super earth planet would i then weigh 1/2 ton?[/quote]
[quote="astrolabe"]Maybe the question should be: "What would my diameter be?"[/quote]
If a 200 lb. BMAONE23 stood on a 5x Earth-mass planet [i]with the same diameter as Earth[/i], he would weigh 1/2 ton (1000 pounds).
Consider this: Mercury has .055 of the mass of Earth, but divide .055 by the square of the ratio of their radii (divide by .146) to get a surface gravity for Mercury equal to .38 of Earth.
Consider this: Mars has .107 of the mass of the Earth, but divide .107 by the square of the ratio of their radii (divide by .284) to get a surface gravity for Mars equal to .38 of Earth.
Consider this: The ratio of the mass of Mars to the mass of Mercury (1.94:1) is approximately the square of the ratio of the radius of Mars to the radius of Mercury (1.39:1), so force of gravity is about the same on the surface of each.
The force of a planet's gravity on an object at a planet's surface is directly proportional to the planet's mass and inversely proportional to the square of its radius.
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If your 5x Earth-mass planet had the same density as Earth, its radius would be the cube root of 5 (about 1.71) times Earth's radius. So start with 1, multiply by 5, divide by the square of 1.71, and you get a surface gravity of 1.71 times that of Earth. So an object or person weighing 200 lbs. on the surface of Earth weighs 342 pounds on this planet.