Study Notes
Forces and energy are fundamental concepts in physics, involving the study of how energy is transferred and conserved, and how forces like gravity and air resistance affect motion.
- Energy — the ability to do work or cause change. Example: Kinetic energy is the energy of motion.
- Energy Transfer — the process of energy moving from one form to another. Example: Chemical energy in fuel is converted to kinetic energy in a car engine.
- Conservation of Energy — a principle stating energy cannot be created or destroyed, only transformed. Example: An electric lamp converts electrical energy into light energy.
- Force — a push or pull acting on an object due to interaction with another object. Example: Thrust increases the speed of a vehicle.
- Gravity — a force that attracts objects towards each other. Example: Earth's gravity pulls objects towards its center.
- Air Resistance — a type of friction that acts against the motion of objects through air. Example: Air resistance slows down a falling feather more than a hammer.
Exam Tips
Key Definitions to Remember
- Energy is the ability to do work or cause change.
- Conservation of Energy states energy cannot be created or destroyed.
- A force is a push or pull acting on an object.
- Gravity is a force that attracts objects towards each other.
- Air resistance is friction between air and a moving object.
Common Confusions
- Confusing mass with weight; mass is the amount of matter, weight is the force of gravity on that mass.
- Thinking energy can be lost; it can only be transformed or transferred.
Typical Exam Questions
- What is energy? Energy is the ability to do work or cause change.
- How does air resistance affect falling objects? Air resistance slows down objects with larger surface areas more than those with smaller ones.
- What does the Law of Conservation of Energy state? Energy cannot be created or destroyed, only transformed.
What Examiners Usually Test
- Understanding of energy transfer and conservation.
- Ability to differentiate between mass and weight.
- Effects of forces like gravity and air resistance on motion.