Question

a body Falls freely. what is constant?

Answer 1

mass will remain contant, gravitational acceleration may change if h is too large

Answer 2

in a free fall, in an object two energies like potential and kinetic

but the total energy after free fall is constant

there is high potential energy in upper side objects while free fall and at ground the potential energy become zero and kinetic energy become high so total energy remains constant.

hope it helps you