From what hight one must drop a piece of ice that is originally at 0°c so it completely melts upon the impact? ignore air resistance and heat losses to the environment.

An owl dives toward the ground with a constant velocity of 4.40 m/s at 53.0° below the horizontal. the sun is directly overhead and casts a shadow of the owl directly below it. what is the speed (in m/s) of its shadow on level ground?