Final answer:
The rate at which thermal energy must be transferred to reduce the body temperature is 80.0 W.
Step-by-step explanation:
To calculate the rate at which thermal energy must be transferred to reduce the body temperature, we can use the equation:
Power = (mass x specific heat capacity x change in temperature) / time
First, we need to calculate the temperature change. The initial temperature is 40.0 °C, and the final temperature is 37.0 °C, so the temperature change is 37.0 - 40.0 = -3.0 °C.
Next, we can plug in the given values into the equation:
Power = (80.0 kg x 4200 J/(kg·°C) x -3.0 °C) / (30.0 min x 60 s/min) + 150 W
Power = -80.0 W
The negative sign on the power indicates that heat is being transferred out of the person's body. So, the rate at which thermal energy must be transferred to reduce the body temperature is 80.0 W. Therefore, the correct answer is option (a) 82.5 W.
Thermal energy refers to the internal energy of a system due to the kinetic energy of its atoms and/or molecules. It is associated with the temperature of an object and is a type of microscopic kinetic energy.
Key points about thermal energy:
Particle Motion: Thermal energy is related to the random motion of particles (atoms or molecules) within a substance. The higher the temperature, the greater the average kinetic energy of these particles.
Heat Transfer: Heat is the transfer of thermal energy between objects with different temperatures. Heat naturally flows from an object with a higher temperature to one with a lower temperature until thermal equilibrium is reached.
Units: The unit of thermal energy in the International System of Units (SI) is the joule (J). Calorie is another common unit for measuring thermal energy, especially in the context of nutrition and thermodynamics.
Specific Heat: Different materials require different amounts of thermal energy to raise their temperature by a certain amount. The specific heat capacity of a substance is the amount of heat energy required to raise the temperature of a unit mass of that substance by one degree Celsius (or one Kelvin).
Thermal Equilibrium: When two objects are in thermal contact and there is no net flow of heat between them, they are in thermal equilibrium. At this point, they have the same temperature.