A meteor melts when it enters the Earth’s atmosphere. Assuming that the meteor is primarily made of iron and that its initial temperature was −125°C outside of Earth’s atmosphere, calculate the minimum speed it must have had before it entered Earth’s atmosphere. (The specific heat, the melting point, and the latent heat of fusion for iron are 450 J/kg.°C, 1808°C, and 2.89 x 10^5 J/kg , respectively.)

The heat of sublimation (ΔHsublimation) of dry ice (solid carbon dioxide) is 570 J/g. Determine the amount of heat required to turn a 5.0-pound bag of dry ice into gaseous carbon dioxide. (Given: 1.00 kg = 2.20 lb)

Assume a coffee mug is completely filled with creamed coffee.  Assume both of their temperatures are initially at 160 Fahrenheit and the atmospheric temperature is 50 Fahrenheit.  How long will it take the coffee mug to reach 60 F due to radiation ignoring the transfer of heat to each other by conduction?  (Take the density of the coffee to be 1.2 g/cm3 , its specific heat to be .90 cal/g.C and the mass of the cup to be 250 grams and its specific heat to be .3 cal/g.C.  Also, take the emissivity of the creamed coffee to be .4)

314.0 kg copper bar is put into a smelter for melting. The initial temperature of the copper is 299.0 K. How much heat in kilojoules must the smelter produce to completely melt the copper bar? (The specific heat for copper is 386 J/kg•K, the heat of fusion for copper is 205 kJ/kg, and its melting point is 1357 K.)