Overview
This lecture introduces the concept of energy, its forms (kinetic and potential), and how energy is used and transformed in daily life.
What is Energy?
- Energy is defined as the ability to do work or cause change.
- We cannot see energy itself but can observe its effects, such as movement, heat, or sound.
- Energy powers machines, lights homes, and enables movement and growth in living organisms.
Forms of Energy
- There are two main forms of energy: kinetic energy and potential energy.
Kinetic Energy
- Kinetic energy is the energy of movement.
- Examples of kinetic energy include mechanical, sound, light, heat, and electrical energy.
Potential Energy
- Potential energy is stored energy due to an object's position, composition, or state.
- Chemical energy, found in fuels like petroleum and wood, is a type of potential energy.
- Gravitational potential energy depends on an object's position above the ground.
- Elastic potential energy is stored when objects like bowstrings are stretched.
Energy Transformations
- Plants convert light energy from the sun into food (sugar), which animals then consume for energy.
- When fuels burn, chemical potential energy is transformed into light and heat.
- Gravitational potential energy of a rock on a hill changes into kinetic energy as it rolls down.
- Pulling back a bow stores elastic potential energy, which becomes kinetic when released.
Key Terms & Definitions
- Energy — the ability to do work or cause change.
- Kinetic Energy — energy possessed by moving objects.
- Potential Energy — stored energy based on position, composition, or state.
- Chemical Energy — potential energy stored in chemical substances.
- Gravitational Potential Energy — potential energy due to an object's height above ground.
- Elastic Potential Energy — potential energy stored by stretching or compressing an object.
Action Items / Next Steps
- Watch related videos on mechanical, sound, light, heat, and electrical energy.
- Explore more about energy forms and conversions as suggested.