A father and son conducted the following simple experiment on a hot dog which measured 12.5 cm in length and 2.2 cm in diameter. They inserted one food thermometer into the midpoint of the hot dog and another one was placed just under the skin of the hot dog. The temperatures of the thermometers were monitored until both thermometers read 20°C, which is the ambient temperature. The hot dog was then placed in 94°C boiling water and after exactly 2 min they recorded the center temperature and the skin temperature of the hot dog to be 59°C and 88°C, respectively. Assuming the following properties for the hot dog: r = 980 kg/m³and c_p= 3900 J/kg·K and using transient temperature charts, determine

(a) The thermal diffusivity of the hot dog,

(b) The thermal conductivity of the hot dog,

(c) The convection heat transfer coefficient.

Transcribed Image Text:

Boiling water 94°C Tsurface Hot dog T. center