A chromium rod is heated by convection in a furnace at 2100 K. The radius of the rod is 5 mm and its initial temperature is 295 K. The average thermal conductivity is 71.5 W/mC and the heat transfer coefficient is 53 W/m2C. Determine the time needed to heat the rod to 1950 K. Specific heat and density of the rod are 616 J/kg C and 7865 kg/m3.