Work and Power

Summary and Exam Tips for Work and Power

Work and Power is a subtopic of Energy Resources and Energy Transfers, which falls under the subject Physics in the Edexcel IGCSE curriculum. Work is done when a force is applied in the direction of an object's displacement, moving it over a distance. The formula for work done is $W = Fd$, where $W$ is work in joules, $F$ is force in newtons, and $d$ is distance in meters. If there is no movement, no work is done.

Gravitational Potential Energy is the energy an object possesses due to its height and gravity. When an object is raised, energy is transferred to its gravitational store, and when it falls, energy is transferred away.

Kinetic Energy is the energy an object has due to its mass and speed, calculated as $\text{Kinetic energy} = \frac{1}{2} \times \text{mass} \times \text{velocity}^2$.

Power is the rate at which energy is transferred or work is done, measured in watts (W).

Exam Tips

• Remember that only the speed is squared when calculating kinetic energy, not the mass or the $\frac{1}{2}$.
• Understand energy reserves and transfer pathways to apply them effectively in questions.
• Always convert distance to meters and force to newtons to ensure work is expressed in joules.
• Efficiency can be expressed as a percentage (0-100%) or as a ratio (0-1). If asked for a ratio, provide your answer as a fraction or decimal.
• Practice applying these concepts in different scenarios to enhance your problem-solving skills.