Heat and Thermodynamics - SS1 Physics Past Questions and Answers - page 5
Discuss the application of thermodynamics in cooking and food preservation. Provide examples of how thermodynamic principles are utilised in processes such as baking, boiling, and refrigeration.
Thermodynamics plays a crucial role in cooking and food preservation processes. In baking, for example, the principle of heat transfer through convection is used to evenly cook the food. The hot air inside the oven circulates and transfers heat to the food, resulting in a uniform baking process.
Boiling is another application of thermodynamics in cooking. The heat applied to a pot of water causes the water molecules to gain energy and undergo a phase change from a liquid to a gas (vapour). This process follows the principles of boiling point and latent heat of vaporisation.
In food preservation, refrigeration relies on the principle of heat transfer through conduction and convection. A refrigerator extracts heat from the food items, lowering their temperature and slowing down the growth of microorganisms that cause spoilage. The compressor in the refrigerator compresses refrigerant gas, causing it to release heat as it condenses, and then the cooled refrigerant circulates to absorb heat from the food items.