What is Energy? Energy is the capacity to do work or cause change. It exists in various forms, known as energy stores , including: Kinetic energy (energy of mot...
Energy is the capacity to do work or cause change. It exists in various forms, known as energy stores, including:
Energy can be transferred from one store to another, but it cannot be created or destroyed. This is known as the principle of conservation of energy. Energy transfers can occur:
During energy transfers, some energy is dissipated or wasted due to friction, heating, or other inefficiencies. This wasted energy is typically in the form of heat, which spreads out and becomes less useful.
Problem: A 10 kg object is lifted 5 meters off the ground. Calculate the increase in gravitational potential energy.
Solution:
Power is the rate at which energy is transferred or work is done. It is measured in watts (W) or joules per second (J/s).
Efficiency is a measure of how much useful energy output is obtained from a given input. It is calculated as: Efficiency = (useful energy output) / (total energy input)
Energy resources can be classified as renewable (e.g., solar, wind, hydroelectric, geothermal, biomass) or non-renewable (e.g., fossil fuels, nuclear). The use of energy resources has environmental impacts, including greenhouse gas emissions, air pollution, and habitat destruction. Developing sustainable energy solutions is crucial for mitigating climate change and environmental degradation.
For more information on energy resources and their environmental impacts, refer to BBC Bitesize and TRH Learning.