A liquid food product (P) is being cooled from 80°C to 30°C in an indirect heat exchanger using cold water (W) as a cooling medium. If the product mass flow rate is 1800 kg/h, determine the water flow rate required to accomplish product cooling if the water is allowed

The rate at which a resting person converts food energy is called one’s basal metabolic rate (BMR). Assume that the resulting internal energy leaves a person’s body by radiation and convection of dry air. When you jog, most of the food energy you burn above your BMR becomes internalenergy that would raise your body temperature if it were not eliminated. Assume that evaporation of perspiration is the mechanism for eliminating this energy. Suppose a person is jogging for “maximum fat burning,” converting food energy at the rate 400 kcal/h above his BMR, and putting out energy by work at the rate 60.0 W. Assume that the heat of evaporation of water at body temperature is equal to its heat of vaporization at 100°C. (a) Determine the hourly rate at which water must evaporate from his skin. (b) When you metabolize fat, the hydrogen atoms in the fat molecule are transferred to oxygen to form water. Assume that metabolism of 1.00 g of fat generates 9.00 kcal of energy and produces 1.00 g of…

Ice of mass 12.8 kg at 0°C is placed in an ice chest. The ice chest has 2.7 cm thick walls of thermal conductivity 0.07 W/m·K and a surface area of 1.29 m2. Express your answers with appropriate mks units. (a) How much heat must be absorbed by the ice during the melting process? (b) If the outer surface of the ice chest is at 39° C, how long will it take for the ice to melt?

A classroom has dimensions 8.00 m x 10.00 m x 3.00 m. A 1000 W electric space heater is being used to warm the room from 5.00°C to 20.00°C on a cold morning. If the density of air is 1.29 kg/m°, and the specific heat capacity of air is 1004 J/(kg-K), how long will it take to heat the room? Assume no loss of thermal energy to the surroundings. A) 1.30 minutes B) 241 minutes C) 45.3 minutes O D) 77.7 minutes