Session 2: Energy Forms & Evidence

Key Idea

Energy is defined as the capacity to make things move or change. Although energy is present everywhere in the universe, it is not always visible to the naked eye. However, we know it exists because it comes in various types, known as forms.

The most common observable forms of energy include light energy, sound energy, motion energy, and thermal energy. Identifying these specific forms helps scientists describe how energy is behaving in a system.

Key Idea

When electrical devices operate, they produce observable changes in the environment, which are called outputs. These outputs serve as tangible evidence that energy is present and is being used by the device.

For example, seeing a glow or hearing a noise are ways to detect energy. By carefully observing these outputs, we can identify exactly which form of energy (such as light or sound) a device is producing at any given moment.

Key Idea

Electrical devices function by acting as a bridge between the power source and a useful result. To do their job, they must take in electrical energy (the input) that transfers through wires and change it into a different form.

This process of changing energy from one type to another is called a conversion. The device converts the invisible electrical input into observable outputs (like motion or sound), allowing the device to perform its intended function.