Conservation of Energy

Active learning works for conservation of energy because students need to see energy transforming in real time to believe it stays constant. Watching a pendulum swing or a roller coaster car move lets students feel the shift between kinetic and potential energy, which makes the abstract concept tangible and memorable.

• 7th Grade
• Science
• 4 activities
• 20 min–50 min

Learning Objectives

1. Analyze the transformation of energy between kinetic and potential forms in a simple pendulum system.
2. Construct an argument, using evidence from observations, that energy is conserved and cannot be created or destroyed.
3. Predict the final speed of an object based on its initial potential energy and the system's efficiency.
4. Explain how energy is transferred and transformed within a closed system, such as a roller coaster.
5. Evaluate the impact of friction and air resistance on energy transformations in real-world mechanical systems.

Inquiry Circle

⏱ 45 min·Small Groups

Inquiry Circle: The Pendulum Tracker

Groups use a simple pendulum and a tape measure to record the height at the start of each swing. They graph how starting height relates to speed at the bottom and track how long the pendulum takes to stop, then use the data to argue that energy transferred to the surroundings rather than vanished.

Prepare & details

Analyze how energy transforms between kinetic and potential forms in a pendulum.

Facilitation Tip: During The Pendulum Tracker, ask students to predict where energy is highest and lowest before each trial to build anticipation and focus their observations.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Think-Pair-Share

⏱ 20 min·Pairs

Think-Pair-Share: Roller Coaster Energy Analysis

Show a diagram or simulation of a roller coaster with labeled heights. Students individually identify where kinetic energy and potential energy peak, then explain to a partner why the coaster cannot return to a height higher than its starting point. The class compiles their reasoning into a shared argument.

Prepare & details

Justify the statement that energy cannot be created or destroyed.

Facilitation Tip: For the Roller Coaster Energy Analysis, circulate and listen for students to use terms like 'energy transfer' and 'friction' when discussing why the car slows down.

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Stations Rotation

⏱ 50 min·Small Groups

Stations Rotation: Energy Transformation Tracking

Three stations each model a different system: a wind-up car, a bouncing ball, and a hand-crank generator. At each stop, students diagram the full energy transformation chain and identify where energy exits the system as heat or sound.

Prepare & details

Predict the final speed of an object given its initial potential energy.

Facilitation Tip: In Energy Transformation Tracking, provide meter sticks and timers so students can quantify changes in energy rather than guessing.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Gallery Walk

⏱ 35 min·Small Groups

Gallery Walk: Energy in Everyday Systems

Student groups create annotated posters showing a chosen system (e.g., a swing, a thrown ball, a charging phone) with arrows mapping each energy transformation. Peers use sticky notes to identify which transformations were correctly shown and ask questions about missing steps.

Prepare & details

Analyze how energy transforms between kinetic and potential forms in a pendulum.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Teaching This Topic

Teachers should start with systems students can manipulate themselves, like pendulums and ramps, to make energy transformations visible. Avoid rushing to formulas; instead, let students describe their observations in their own words first. Research shows that students grasp conservation better when they connect it to everyday experiences, so use real-world examples like bouncing balls or swinging swings to ground the concept.

What to Expect

Students will clearly explain how energy transforms in a system, label energy types correctly, and track where energy goes when it seems to disappear. They will use terms like kinetic energy, potential energy, and thermal energy to support their claims with evidence from observations.

Watch Out for These Misconceptions

Common Misconception

During Collaborative Investigation: The Pendulum Tracker, watch for students who say the pendulum 'loses energy' when it swings lower.

What to Teach Instead

Redirect them to touch the surface where the pendulum hangs and feel for warmth, then ask them to consider what happened to the missing energy.

Common Misconception

During Think-Pair-Share: Roller Coaster Energy Analysis, watch for students who claim the roller coaster car keeps all its energy as it moves.

What to Teach Instead

Have them measure the track’s height at different points and compare it to the car’s speed to show how energy changes form and location.

Assessment Ideas

Exit Ticket

After Collaborative Investigation: The Pendulum Tracker, give students a diagram of a pendulum at its highest and lowest points. Ask them to label where potential energy is greatest, where kinetic energy is greatest, and write one sentence explaining how energy transforms between these two points.

Quick Check

During Station Rotation: Energy Transformation Tracking, present students with a scenario: 'A toy car starts at the top of a ramp with 100 Joules of potential energy. It rolls down and reaches the bottom with 80 Joules of kinetic energy.' Ask them to write the destination of the other 20 Joules and justify their answer using vocabulary terms.

Discussion Prompt

After Gallery Walk: Energy in Everyday Systems, pose the question: 'If energy cannot be destroyed, why does a bouncing ball eventually stop bouncing?' Facilitate a class discussion where students use terms like kinetic energy, potential energy, transformation, and friction to explain the energy losses to heat and sound.

Extensions & Scaffolding

• Challenge students to design a roller coaster track that maximizes the number of loops while ensuring the car completes the course without stopping halfway.
• Scaffolding: Provide a graphic organizer with labeled energy types and arrows to help students map transformations during Station Rotation.
• Deeper exploration: Have students research how engineers use conservation of energy in roller coaster design, focusing on safety and efficiency.

Key Vocabulary

Potential Energy	Stored energy an object possesses due to its position or state. For example, a ball held high has more potential energy than when it is on the ground.
Kinetic Energy	The energy an object has due to its motion. A moving car possesses kinetic energy, which increases with its speed.
Energy Transformation	The process where energy changes from one form to another, such as when potential energy is converted into kinetic energy as an object falls.
Conservation of Energy	A fundamental principle stating that energy cannot be created or destroyed, only changed from one form to another or transferred between systems.
System	A collection of interacting or interdependent components forming a unified whole. In physics, a system can be a pendulum, a roller coaster, or even the Earth.