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.
So a planet this size 100kg would weigh? What?
The equation for force of gravity is F = GMm / r² where
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.
Neat! Thanks!