The weight of the astronaut on Earth is:
where m is the mass of the astronaut, which does not change from Earth to the Moon, while gE is the Earth's gravitational acceleration.
On the moon, g is 1/6 of the value of g on Earth:
And therefore the weight on the Moon is
Dividing the two expressions, we have
So, the ratio between the weight of the astronaut on the moon and on the Earth is 1/6. Since the weight on Earth is
, we can find the weight on the Moon: