Study Notes
Work and power involve the transfer of energy when a force moves an object over a distance. Power measures how quickly this energy transfer occurs.
- Work — the energy transferred when a force moves an object over a distance. Example: Pushing a box across the floor.
- Gravitational Potential Energy — the energy an object has due to its height and gravity. Example: A book on a shelf.
- Kinetic Energy — the energy an object has due to its mass and speed. Example: A moving car.
- Power — the rate at which work is done or energy is transferred. Example: A light bulb using energy to produce light.
Exam Tips
Key Definitions to Remember
- Work done = Force x Distance
- Power is the rate of energy transfer
- Kinetic energy = ½ x mass x velocity²
Common Confusions
- Only the speed is squared in the kinetic energy formula, not the mass or ½.
- Work is only done if the object moves in the direction of the force.
Typical Exam Questions
- What is the formula for work done? Work done = Force x Distance
- How do you calculate kinetic energy? Kinetic energy = ½ x mass x velocity²
- What is power? Power is the rate at which work is done or energy is transferred.
What Examiners Usually Test
- Understanding of energy transfer and work done
- Ability to calculate kinetic and potential energy
- Application of formulas to solve problems