Work, Power, and Efficiency

This section delves deeper into the concepts of work, power, and efficiency, providing detailed explanations and practical examples. It emphasizes the relationship between work done and energy transferred, and introduces the concept of power as the rate of energy transfer.

Definition: Work done is equal to energy transferred, expressed by the equation W = F × d (Work = Force × distance).

Example: The page presents a problem involving Jack doing 405 J of work while walking 15 m uphill, demonstrating how to calculate the force exerted.

Highlight: The concept of energy conservation is emphasized, stating that energy is never created or destroyed, only transformed into different forms.

Vocabulary: Sankey diagrams - Visual representations of energy transfer, where the width of arrows is proportional to the amount of energy transferred.

Convection

This section explains the process of convection, another important energy transfer mechanism. It details how heat is transferred in fluids (liquids and gases) through the movement of particles.

Definition: Convection is the transfer of heat energy in fluids through the movement of heated particles.

Highlight: The page emphasizes that convection occurs due to differences in density between heated and cooler parts of a fluid.

Example: The formation of convection currents is illustrated, showing how less dense, warmer fluid rises while denser, cooler fluid sinks.

Vocabulary: Convection currents - The circular motion of fluid caused by differences in temperature and density.

Energy Stores and Equations

This page introduces the fundamental concepts of energy stores and key GCSE Physics equations. It covers various energy stores such as chemical, kinetic, gravitational, elastic, thermal, magnetic, electrostatic, and nuclear. The page also presents essential equations for calculating kinetic energy, efficiency, thermal energy, elastic potential energy, electrical energy, and gravitational potential energy.

Vocabulary: Specific heat capacity - The amount of energy required to raise the temperature of 1 kg of a substance by 1°C (J/kg°C).

Example: The page provides an example of energy transfer in a camping stove, where chemical energy from fuel is converted to thermal energy.

Highlight: The efficiency equation is presented as (useful energy output / total energy input) × 100, which is crucial for understanding energy conservation and transfer.