A wooden cube is floating in a small fish tank that is filled with water. Imagine that you take this setup to a space station on the Moon. Air pressure and temperature inside the station are similar to conditions on Earth.

the cube does not move

Explanation:

The Archimedes principle is fulfilled for the wooden cube in the Earth

              B = W

              ρ g V = m g

When this cube travels to the Moon, the value of the gravity acceleration changes,

               ρ g_moon V = m g_moon

               ρ V = m

So we can see that the buoyancy of the cube does not change when changing from Earth to the Moon

In summary the cube does not move

where is the circuit diagram ?