Energy Stores and Transfers Energy exists in different forms, known as energy stores . Some common energy stores include: Kinetic energy - energy of motion Grav...
Energy exists in different forms, known as energy stores. Some common energy stores include:
Energy can be transferred from one store to another through various processes, such as:
The principle of conservation of energy states that energy cannot be created or destroyed; it can only be transferred or transformed from one form to another. However, in real-world situations, some energy is often dissipated or wasted due to factors like friction, air resistance, or heat loss.
Problem: A 2 kg object is dropped from a height of 10 m. Ignoring air resistance, calculate its kinetic energy just before hitting the ground.
Solution:
Power is the rate at which energy is transferred or converted from one form to another. It is calculated as the amount of energy transferred or converted per unit time:
Power = Energy transferred or converted / Time taken
Efficiency is a measure of how much of the input energy is usefully transferred or converted. It is calculated as the ratio of useful output energy to input energy, often expressed as a percentage:
Efficiency = (Useful output energy / Input energy) × 100%
Energy resources can be categorized as renewable (e.g., solar, wind, hydroelectric, geothermal, biomass) or non-renewable (e.g., fossil fuels like coal, oil, and natural gas, nuclear). The choice of energy resources has significant environmental impacts, including greenhouse gas emissions, air and water pollution, and land use changes.
For more information on energy resources and their environmental impacts, refer to BBC Bitesize and TRH Learning.