Plank’s equation is being used to estimate the convective heat transfer coefficient in a food being frozen in an air-blast freezer. it took a product 20 minutes to freeze in the freezer. the product is in the shape of an infinite cylinder with a diameter of 2 cm. the properties of the product are as follows: thermal conductivity of frozen material = 1.8 w/(m °c), density = 890 (kg/m3), latent heat of fusion = 260 kj/kg, and initial freezing point = -1.9 °c. the initial temperature of the product is 25°c and the air temperature is -35°c. estimate the heat transfer coefficient of the food.

Sally turns on her cellular telephone to speak to her friend who is located thousands of miles away. which of the following best describes how such a telephone is able to transmit and receive information? a. the cellular telephone transmits, receives, and encodes information using only sound waves. b. the cellular telephone transmits, receives, and encodes information using only electromagnetic waves. c. the cellular telephone transmits information by electromagnetic waves to a receiver which then encodes them and produces sound. d. the cellular telephone transmits information by sound waves to a receiver which then encodes them and produces electromagnetic waves.