Consider a long, pure iron rod with a diameter of 2 cm and at an initial uniform temperature of 27 C. It is suddenly heated by uniform and constant convection with T_inf = 227 C and h_inf = 200 W/m^2 K. Ignoring radiation, determine the center temperature of the rod after 45 seconds.

Consider a 150 W incandescent lamp in a room at 25 °C. The filament of the lamp is 5 cm long and has a diameter of 0.5 mm. The emissivity of the filament is 0.90. The diameter of the glass bulb of the lamp is 8 cm. The inside surface temperature of the glass bulb is 150 °C. Determine: (a) the heat flux, in W∙m-2, on the surface of the filament, (b) the heat flux, in W∙m-2, on the surface of the glass bulb, and (c) the surface temperature of the filament. The surface area of a sphere is ? = 4??2, and the volume of a sphere is ? = (4?/3)?3.

A large steel plate (1.0% carbon) 5.0 cm thick is initially at a temperature of 425 °C. It is suddenly exposed on both sides to a convective environment with h = 285 W/m² °C, and T. = 65 °C. Determine the centerline temperature and the temperature inside the body 1.25 cm from the surface after 24 minutes. k= 41 W/m-K a = 1.172 × 105 m²/s (at 20 °C)

A 2-cm-diameter plastic rod has a thermocouple inserted to measure temperature at the center of the rod. The plastic rod (r = 1190 kg/m3, cp = 1465 J/kg·K, and k = 0.19 W/m·K) was initially heated to a uniform temperature of 70°C, and allowed to be cooled in ambient air temperature of 25°C. After 1388 s of cooling, the thermocouple measured the temperature at the center of the rod to be 30°C. Determine the convection heat transfer coefficient for this process. Solve this problem using analytical one-term approximation method (not the Heisler charts).