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The gravity on a rocket planet three times the size of the earth...?
...would be what, and would it be tolerable to lifeforms from earth?
Ooops, I mean "rocky planet"
- 1 month agoFavorite Answer
Depends on the density of the planet.
The further out from the center of gravity of the planet you are, the less you weigh; however, the *more mass* there is, the *more* you'd weigh.
So... Earth has a density of 5.5... Let's assume the volume of this new planet is 3 times that of the Earth, and maintains the same density - so, the mass of the new planet is also 3 times that of the Earth.
V = 4/3 x pi x r^3...
For Earth, our radius is "1" - so:
V = 4/3(3.141592)(1)^3
V = 4.189.
With the new planet, 3V = 4/3 x pi x r^3... so:
3(4.189) = 4/3 x (3.141592) x r^3
which boils down to
3 = r^3, so r = 1.442
The formula for finding the force of gravity between two objects is:
F = G(m1)(m2) / r^2, where the force F equals the gravitational constant G, times the mass of the first object (the planet) times the mass of the second object (say it's you or me), all divided by r^2.
So, the force of gravity on the new planet is going to increase the mass of M1 by 3 times, and it's going increase the radius by 44.2%:
F = G(3m1)(m2) / (1.442^2) (since G and m2 don't change, let's remove them.)
F = 3/1.442^2 = 3/2.079 = 1.445
so - if you weigh 100 newtons on Earth, you'd weigh 144.5 newtons on the new planet.
- Anonymous1 month ago
What exactly is a "rocket planet".
"3 times the size of the Earth" is meaningless. 3 times the mass, 3 times the diameter, both?
Surface gravity is a function of mass and radius. We need both to determine surface gravity.
And if life evolved in that environment it would survive just fine.
- CarolOklaLv 71 month ago
The size of the planet is not what is important. It's the MASS of the planet that determines the magnitude of the force of gravity. 3 times the Mass would be?3 times the gravity. Most people would find that intolerable.