Overview
This lecture covers the main types of energy stores, their definitions, and examples, focusing on how energy can be transferred, stored, or dissipated but never created or destroyed.
Types of Energy Stores
- Energy exists in different stores and can be transferred, stored, or dissipated.
- The main types of energy stores are: magnetic, internal (thermal), chemical, kinetic, electrostatic, elastic potential, gravitational potential, and nuclear.
Examples and Descriptions of Energy Stores
- Magnetic: Energy stored by moving repelling or attracting poles (e.g., fridge magnets, maglev trains).
- Internal (thermal): Total kinetic and potential energy of particles; hotter objects vibrate more (e.g., hot drinks, human bodies).
- Chemical: Energy stored in chemical bonds (e.g., food, muscles, batteries).
- Kinetic: Energy of moving objects (e.g., runners, buses).
- Electrostatic: Energy from moving repelling or attracting charges (e.g., thunderclouds, generators).
- Elastic potential: Energy stored in stretched or squashed objects (e.g., compressed springs, drawn catapults).
- Gravitational potential: Energy stored at height (e.g., aeroplanes, kites).
- Nuclear: Energy in the nucleus of an atom (e.g., nuclear reactors, uranium).
Key Terms & Definitions
- Energy store — The capacity for doing work, held in various forms or places.
- Magnetic — Energy from the position of magnetic poles.
- Internal (thermal) — Energy from the movement and positions of particles in a substance.
- Chemical — Energy stored in bonds between atoms or molecules.
- Kinetic — Energy from an object's movement.
- Electrostatic — Energy from the position of charged particles.
- Elastic potential — Energy from stretching or squashing objects.
- Gravitational potential — Energy due to an object's position above the ground.
- Nuclear — Energy stored within the atomic nucleus.
Action Items / Next Steps
- Review the next section on energy transfers.
- Study related topics: work, power, efficiency, and energy demands.