Discover Mechanical, Electrical, and Chemical Energy All Around You

Energy is the ability to do work or cause change, and it comes in many forms. In this topic, you will focus on three key types: mechanical energy, electrical energy, and chemical energy. These three forms appear everywhere in your daily life, from the food you eat to the devices you use.

Before diving in, you should already be familiar with Energy Types: Potential and Kinetic Energy, which forms the foundation for understanding mechanical energy. You will build on that knowledge here.

Mechanical energy is the combination of kinetic energy (energy of motion) and potential energy (energy stored due to position or shape). Any object that is moving or is in a position where it could move has mechanical energy.

A ball rolling down a hill has kinetic mechanical energy because it is in motion. At the top of the hill, that same ball has gravitational potential energy because of its height. As it rolls down, the stored energy converts into motion energy this is an energy transformation you will study further in Energy Conversion: Transformation Between Forms.

A compressed spring inside a toy car stores elastic potential energy, which is also a form of mechanical energy. When released, that stored energy becomes kinetic energy that launches the car forward. A stretched rubber band works the same way it stores elastic potential energy ready to be released as motion.

You can explore how mechanical energy relates to force and work in Mechanical Advantage: Work and Force Relationships and Work and Time: Relationship Between Power and Energy.

Electrical energy is the energy carried by moving electric charges (electrons) through conductors like wires. It powers the devices you use every day light bulbs, fans, televisions, and charging phones all rely on electrical energy.

When a light bulb is connected to a power outlet, electrical energy flows through the filament and is converted into light and heat. An electric fan converts electrical energy into mechanical energy as its motor spins the blades. These are examples of energy transformation one form changing into another.

You will explore electrical energy in much greater depth when you study Circuit Components: Current, Voltage, and Resistance and Circuit Types: Series and Parallel Introduction. Understanding electrical energy now prepares you for those topics.

Chemical energy is energy stored in the bonds between atoms and molecules. It is released during chemical reactions. You encounter chemical energy every time you eat food, use a battery, or watch wood burn in a fire.

An apple stores chemical energy in its sugars and carbohydrates. When you eat it, your body breaks those molecular bonds and releases the energy for movement and growth converting chemical energy into mechanical energy. A battery also stores chemical energy; when connected in a circuit, a chemical reaction releases that energy as electrical energy to power a device.

Wood stores chemical energy in its molecular bonds. When it burns (combustion), that energy is released as heat and light. This connects to what you learned in Chemical Properties: Reactivity, pH, and Combustibility. You will also see chemical energy at work in Cell Functions: Transport and Energy Production.

Mechanical Energy: Mechanical energy is the total energy an object has due to its motion or its position. You can think of it as the combination of kinetic energy and potential energy in a physical object for example, a spinning top or a ball rolling down a hill.

Electrical Energy: Electrical energy is the energy carried by moving electric charges (electrons) through a conductor like a wire. It is what flows through circuits to power devices such as light bulbs, fans, and phones.

Chemical Energy: Chemical energy is energy stored in the molecular bonds that hold atoms together in a substance. It is released during chemical reactions you find it in food, fuel, and batteries.

Kinetic Energy: Kinetic energy is the energy that any object has because it is currently moving. The faster an object moves, the more kinetic energy it has a rolling ball and a moving bicycle both have kinetic energy.

Potential Energy: Potential energy is stored energy based on an object's position or state. An object at a great height has gravitational potential energy, and a compressed or stretched object has elastic potential energy.

Gravitational Potential Energy: Gravitational potential energy is the stored energy an object has because of its height above the ground. The higher an object is, the more gravitational potential energy it has a book on a tall shelf has more than a book on the floor.

Elastic Potential Energy: Elastic potential energy is the stored energy in an object that has been stretched or compressed, such as a rubber band or a spring. When released, this energy converts into kinetic energy.

Energy Transformation: An energy transformation is when energy changes from one form into another. For example, chemical energy in a battery transforms into electrical energy, which then transforms into mechanical energy in a toy car's motor.

Energy of Motion: Energy of motion is another way to describe kinetic energy it is the energy an object possesses simply because it is moving. Any moving object, from a rolling ball to a spinning fan blade, has energy of motion.

Stored Energy: Stored energy refers to energy that is held in an object or substance and has not yet been released. Chemical energy in food and elastic potential energy in a stretched rubber band are both examples of stored energy.

You can practice identifying energy types by looking at everyday objects and asking: Is it moving? (kinetic/mechanical) Is it in a high position or compressed? (potential/mechanical) Does it use wires and electrons? (electrical) Is energy stored in its chemical bonds? (chemical).

Try classifying these examples: a roller coaster at the top of a hill (gravitational potential energy mechanical), a flashlight turning on (chemical energy from batteries electrical light), a person running after eating lunch (chemical mechanical), and a wind turbine spinning to generate power (mechanical electrical). This connects to Energy Conversion: Transformations Between Forms and Efficiency: Energy Loss in Systems.

You will also find it helpful to explore Energy Efficiency: Power Consumption and Energy Transfer: Conduction, Convection, and Radiation as you advance your understanding.

You are already familiar with Energy Types: Potential and Kinetic Energy and Energy Conversion: Transformations Between Forms, which are the foundation for this topic. You have also studied Chemical Properties: Reactivity, pH, and Combustibility, which explains why chemical energy is released during reactions like burning.

Your knowledge of Energy Flow: Food Webs and Energy Transfer also connects here the chemical energy stored in food moves through ecosystems as organisms eat one another, which you will revisit in Energy Flow: Food Webs and Energy Pyramids.

This topic connects to many other important science concepts. Here is how they all fit together in your learning journey:

Topics that build directly on this one: You will use your understanding of electrical energy when you study Circuit Components: Current, Voltage, and Resistance and Circuit Types: Series and Parallel Introduction. You will also apply your knowledge of energy forms in Energy Transfer: Conduction, Convection, and Radiation, Energy Efficiency: Power Consumption, Phase Changes: Energy in Transitions, and Cell Functions: Transport and Energy Production.

Closely related topics you should explore: Energy Conversion: Transformation Between Forms shows you exactly how mechanical, electrical, and chemical energy switch from one to another. Types of Changes: Physical vs. Chemical Changes and Reactions: Signs of Chemical Reactions help you understand when chemical energy is being released. Mechanical Advantage: Work and Force Relationships, Work and Time: Relationship Between Power and Energy, and Efficiency: Energy Loss in Systems all deepen your understanding of mechanical energy in action.

Machines and force applications: You will see mechanical energy at work when you study Machine Types: Levers, Pulleys, Wheels, and Inclined Planes, Complex Machines: Combinations of Simple Machines, and Force Applications: Real-World Applications. These topics show you how mechanical energy is used to make work easier.