Learn: Conservation of Energy

Welcome!Today we’ll explore Conservation of Energy, a key topic in physics. We’ll learn about energy stores, transfers, efficiency, and work done. Let’s get started!

What is Conservation of Energy?The principle of conservation of energy states that energy cannot be created or destroyed. It can only be transferred between energy stores or transformed into different forms. This principle helps us understand how energy moves and changes in physical processes.

Energy StoresEnergy exists in different stores, such as kinetic energy (energy of movement), gravitational potential energy (energy stored due to height), and thermal energy (energy due to heat). These stores can transfer energy during processes like movement or heating.

Energy TransfersEnergy is transferred between stores through mechanical work (forces acting on an object), heating, or waves. For example, when a ball is thrown, energy is transferred mechanically to the kinetic energy store of the ball.

Work DoneWork done occurs when energy is transferred by a force. The formula is Work done = Force × Distance. For example, lifting a box transfers energy to its gravitational potential store.

EfficiencyEfficiency measures how much energy is usefully transferred. The formula is Efficiency = Useful energy output ÷ Total energy input × 100. Machines are never 100% efficient because some energy is always wasted, often as thermal energy.

PowerPower is the rate of energy transfer. The formula is Power = Energy transferred ÷ Time. For example, a powerful machine transfers energy quickly.

Review Time!Great work! You've learned about energy stores, transfers, efficiency, and work done. Let’s test your understanding with a few review questions.