Study Notes
Energy transfers involve the movement of energy between different stores such as chemical, kinetic, gravitational, and others, through processes like mechanical, electrical, heating, and radiation. The principle of conservation of energy states that energy cannot be created or destroyed, only transferred or transformed.
- Energy Transfer — the movement of energy from one store to another Example: Gravity accelerating an object, converting potential energy to kinetic energy.
- Kinetic Energy (KE) — energy due to motion Example: A moving car.
- Gravitational Potential Energy (GPE) — energy due to position in a gravitational field Example: A book on a shelf.
- Elastic Potential Energy (EPE) — energy stored when an object is stretched or compressed Example: A stretched rubber band.
- Thermal Energy — energy due to temperature Example: Heat from a fire warming an object.
- Conservation of Energy — energy cannot be created or destroyed, only transferred Example: A pendulum converting kinetic energy to potential energy and back.
Exam Tips
Key Definitions to Remember
- Energy Transfer: Movement of energy from one store to another
- Conservation of Energy: Energy cannot be created or destroyed
Common Confusions
- Confusing energy transfer with energy creation
- Misunderstanding that heat itself rises, rather than hot gases or liquids
Typical Exam Questions
- What happens to energy when a ball is thrown upwards? Kinetic energy is converted to gravitational potential energy.
- How is energy transferred in a filament light bulb? Electrical energy is converted into light and heat energy.
- What does the conservation of energy principle state? Energy cannot be created or destroyed, only transferred or transformed.
What Examiners Usually Test
- Understanding of different energy stores and transfers
- Application of the conservation of energy principle
- Ability to describe energy changes in practical examples