Assume that a hailstone at 0 C falls through air at a uniform temperature of 0 C and lands on a sidewalk also at this temperature.
From what initial height must the hailstone fall in order to entirely melt on im-pact? The acceleration due to gravity is 9.8 m/sec? and the latent heat of fusion of water is 3.3 × 105 J/kg.
Answer in units of km.