Aspherical hailstone that has a radius r, is formed in a high-altitude cloud at -20°c. consider ro a parameter that takes values from 2.5mm to 12.5 mm with increments of 2.5 mm. if the stone begins to fall through warmer air at 5°c, determine for each value of ro: a) how long will it take before the outer surface begins to melt b) what is the temperature of the stone's center at this point in time c) how much energy (j) has been transferred to the stone in this time interval a convection heat transfer coefficient of 250 w/m²k may be assumed, and the properties of the hailstone may be taken to be those of ice. clearly state all the assumptions made, indicate the heat transfer case and the solution equations that apply. verify the validity of the solution for each value of ro. plot the three results against the values of ro.