When we look at heat transfer problems that include phase transitions, there can bemanynec-essary steps. Consider a material of massmthat undergoes two phase transitions: from solid toliquid and then from liquid to gas. It starts at an initial temperature ofT0(well below the meltingtemperature ofTm) and it heated until it is a gas at a temperature ofTf(well above the boilingtemperature ofTv). How many different steps (simple temperature changes or phase transitions)of heat transfer would you need for this problem