this post was submitted on 05 Sep 2024
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Futurology

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[–] [email protected] 0 points 1 week ago (1 children)

So a planet this size 100kg would weigh? What?

[–] [email protected] 0 points 1 week ago (1 children)

The equation for force of gravity is F = GMm / r² where

  • G is the gravitational constant
  • M is the mass of the planet
  • m is the mass of the object being weighed
  • r is the radius of the planet / distance between the centers of mass of two objects

The equation shows that gravity scales linearly with mass, and scales inversely with the square of distance. The article says K2-18 b is 8.6 times Earth's mass, and 2.6 times Earth's radius. So the weight of a 100 kg mass would be:

F = 100 × 8.6 / (2.6)²

which works out to a weight of about 127 kg, or 1.27 times heavier.

[–] [email protected] 0 points 1 week ago

Neat! Thanks!

[–] [email protected] 0 points 1 week ago

I read this as "weeb discovers..." and was a little disappointed.