What does twain satirize in his description of the church service and the hogs that sleep under the floor?

nigger, that word was originated for white folks   to keep black people under

and when black people use it, they know that's just how they greet each other

and when white folks use it, they know there's a double meaning under

~kinetic ~potential

explanation:

kinetic and potential energies would be types of mechanical energies.