Lesson Notes By Weeks and Term v5 - Grade 6

Lesson Video

This page supports the lesson note with a companion video and a short classroom-ready summary.

For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.

Performance objectives

• Define energy and give examples of its different forms.
• Identify and classify renewable and non-renewable energy sources.
• Describe simple energy systems and trace the flow of energy.
• Explain the difference between renewable and non-renewable sources with South African examples.
• Illustrate how energy is converted from one form to another.

Lesson summary

Energy is everywhere! It makes things move, grow, and even keeps us alive. In South Africa, like everywhere else, we use energy for almost everything we do – from cooking our food to powering our schools and hospitals. This week, we're going to explore different types of energy, where they come from (sources), and how they work together in systems. Understanding energy is crucial because it helps us make informed decisions about how we use it, especially concerning our environment and future. South Africa faces energy challenges, like load shedding, so it's more important than ever for young scientists like you to understand energy and how we can use it responsibly.

Lesson notes

What is Energy? Energy is the ability to do work. Work, in science, means moving or changing something. Everything that happens around us needs energy. We can't see energy directly, but we can see its effects. Think about kicking a soccer ball. You use energy from your body to make the ball move. That's work!

Forms of Energy: Light Energy: Energy we can see. It comes from the sun, light bulbs, and fire. Plants use light energy from the sun to make food (photosynthesis).

Heat Energy (Thermal Energy): Energy that makes things warm. Fire, the sun, and even rubbing your hands together create heat energy.

Sound Energy: Energy that we can hear. It's produced by vibrating objects, like a drum or a speaker.

Movement Energy (Kinetic Energy): Energy of moving objects. A car driving, a person running, and water flowing all have movement energy.

Electrical Energy: Energy of moving electric charges (electrons). This is the energy that powers our lights, TVs, and computers.

Chemical Energy: Energy stored in the bonds of molecules. It’s released when a chemical reaction happens. Food contains chemical energy which our bodies convert to other forms of energy. Fuel like petrol or wood also contains chemical energy.

Potential Energy: Energy stored in an object due to its position or condition. A rock sitting at the top of a hill has potential energy. A stretched rubber band also has potential energy.

Energy Sources: Energy sources are where we get the energy we use. We can divide them into two main categories: Renewable Energy Sources: These are energy sources that can be replenished naturally over a relatively short period. They won't run out!

Examples include: Solar Energy: Energy from the sun. In South Africa, we have lots of sunshine, making solar power a great option. We can use solar panels to convert sunlight into electricity.

Wind Energy: Energy from the wind. Wind turbines convert wind energy into electricity. Coastal areas in South Africa often have strong winds, making them suitable for wind farms.

Hydro Energy (Hydropower): Energy from moving water. Dams can be used to generate electricity. The Gariep Dam and Vanderkloof Dam are important examples in South Africa.

Biomass Energy: Energy from burning organic matter, like wood, sugarcane waste (bagasse), or animal dung. This is more common in rural areas but can contribute to air pollution if not done carefully.

Geothermal Energy: Energy from the heat inside the Earth. South Africa doesn't have many accessible geothermal resources.

Non-Renewable Energy Sources: These are energy sources that exist in limited quantities and cannot be easily replaced once used. They will eventually run out.

Examples include: Coal: South Africa has large coal reserves, and we currently rely heavily on coal-fired power plants for electricity generation.

However, burning coal causes air pollution and contributes to climate change.

Oil (Petroleum): Oil is used to make petrol, diesel, and other fuels. We import a significant portion of our oil needs.

Natural Gas: A gas used for heating and electricity generation. South Africa has some natural gas reserves, but we also import some.

Nuclear Energy: Energy from splitting atoms of uranium. South Africa has one nuclear power plant, Koeberg.

Energy Systems: An energy system is a set of interacting parts that work together to transfer or transform energy.

Example 1: A Solar Cooker: Source: Sun (Solar Energy)

Input: Sunlight shines on a reflective surface (like aluminum foil).

Process: The reflective surface concentrates the sunlight onto a pot or cooking container. This heats up the container. Light energy is converted to heat energy.

Output: Food cooked by the heat energy.

Example 2: A Bicycle: Source: Your body (Chemical Energy from food)

Input: You pedal the bicycle. Your muscles convert chemical energy into movement (kinetic) energy.

Process: The kinetic energy of your legs turning the pedals is transferred through the chain to the wheels, making them turn.

Output: The bicycle moving forward.

Energy Conversions: Energy can change from one form to another. This is called energy conversion.

Here are some examples: A light bulb converts electrical energy into light energy and heat energy. A car engine converts chemical energy (from petrol) into heat energy and movement energy. A solar panel converts light energy (from the sun) into electrical energy. When you eat food, your body converts the chemical energy in the food into movement energy, heat energy, and other forms of energy needed to keep you alive.