A helicopter is hovering at an altitude of 3 km when a panel from below it dislodged and fell to the ground (Figure below). The mass of the panel is 60 kg, and hits the ground with a speed of 135 m/s. How much mechanical energy is dissipated by air resistance during panel descent? Panel falls from this height E U K-0 Terminal velocity reached here E U K E has decreased; U has decreased; K is constant