suppose a ball is raised to a certain height from the floor. thus, this ball$-$earth system has some gravitational potential energy $($ui$).$ when the ball is dropped from this height, the kinetic energy of the ball increases as it fall down. if air resistance is not neglected, how do the kinetic energy $($kf$)$ just before the ball hits the floor compare to the initial gravitational energy $($ui$)$ of the ball$-$earth system?