Introduction

Students will discover how energy transformations, beginning from the Sun and even ancient stellar fusion, provide the energy harnessed in our everyday lives. Students will trace the energy transformations of the world’s major energy sources – biomass, bioenergy, natural gas, coal, oil, solar, wind, geothermal, and nuclear – from stellar fusion to the electricity in our homes and the motion of our vehicles.

Resources

• Understanding Energy Transformations: Reading
• Reading and Video: Slide Deck
• Student Activity 1: Flow Charts (Answer Key below). Various versions are available for different ages and reading levels. Assign them for independent, group, or whole-class activities.
• Student Activity 2: Challenge Questions (Answer Key below). Encourage students to analyze and synthesize energy transformations and connect concepts to real life.

Challenge Questions – Answer Key

1. Natural Gas; Coal; Oil; Wind; Hydro; Nuclear; Geothermal

2. For each scenario below, decide whether the energy is transferring from the object (exerting kinetic energy) or to the object (gaining potential energy). Explain your reasoning.

1. The Sun heats up the Earth, which in turn warms up the air near the Earth’s surface. In this scenario, the air is gaining potential energy because the warmer the air gets, the more potential it has to start rising (moving).
2. The warm air begins to rise, causing the cool air in the atmosphere to rush down to take its place, generating wind currents. In this scenario, the air is exerting kinetic energy, because (reasoning will vary) the air is now in motion, moving along air currents.
3. Water builds up in the reservoir behind the dam. In this scenario, the water is gaining potential energy, because the more water that builds up, the more potential it has to start rushing down the dam.
4. The dam’s gates are opened and the water rushes downward. In this scenario, the water is exerting kinetic energy, because the water is now in motion, rushing downward as gravity pulls.

3. Answers will vary.
Example: The energy we need to live, grow, and develop starts with the Sun! The Sun gives off radiant energy (light energy), which is absorbed by plants through photosynthesis. During this process, plants transform the Sun’s radiant energy into chemical energy, which is stored in their leaves, stems, and fruits.
When animals (including humans) eat plants, we take in that chemical energy and use it for growth, movement, and body functions. Some animals eat other animals that have eaten plants, passing the energy along the food chain. Our bodies break down food through digestion, and the stored chemical energy is converted into thermal energy (body heat) and mechanical energy (movement).
So, the energy transformation looks like this: Radiant energy (Sun) → Chemical energy (plants) → Chemical energy (food) → Mechanical & thermal energy (humans and animals)
This process keeps all living things alive and moving!

4. Design a simple device that converts energy from one form to another.
Examples:

• Chain-reaction contraption or machine.
• Hand-crank generator.
• Solar-powered fan.
• Wind-powered LED light.
• Bicycle-powered electricity.

Energy Transformations Flow Chart – Answer Key