Physics · Grade 11

Active learning ideas

Elastic Potential Energy

Active learning works for elastic potential energy because students need to see the nonlinear relationship between force and displacement firsthand. When they stretch springs and graph data, the shift from linear force to quadratic energy becomes clear, fixing common misconceptions. Hands-on work also builds confidence in applying Hooke's Law to real energy calculations.

• Ontario Curriculum Expectations
• HS-PS3-1

• 35–60 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 50 min · Small Groups

Lab Investigation: Hooke's Law Verification

Provide springs, masses, and rulers. Students hang masses, measure extensions, and record force-displacement data. They plot graphs to determine k from the slope, then calculate E_e for various x values. Discuss linearity and deviations.

Explain how elastic potential energy is stored in a compressed or stretched spring.

Facilitation Tip

During the Hooke's Law lab, have students record force-extension data in a shared spreadsheet so they can immediately see patterns when calculating energy.

What to look for

Provide students with a spring, a set of masses, and a ruler. Ask them to measure the extension of the spring for three different masses, calculate the spring constant 'k' for each trial, and determine the average spring constant. Then, ask them to calculate the elastic potential energy stored in the spring when stretched by 0.10 m.

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

Activity 02

• Stations Rotation
• 60 min · Small Groups

Design Challenge: Projectile Launcher

Groups select springs or rubber bands to build a launcher aiming for a target distance. Calculate required E_e based on projectile mass and desired velocity. Test, measure outcomes, and iterate designs to optimize launch.

Analyze the relationship between the spring constant and the amount of energy stored.

Facilitation Tip

For the projectile launcher challenge, provide rulers marked in centimeters to standardize displacement measurements across groups.

What to look for

On an index card, ask students to write the formula for elastic potential energy and define each variable. Then, pose a scenario: 'If you double the displacement of a spring, how does the stored elastic potential energy change? Explain your answer.'

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

Activity 03

• Stations Rotation
• 35 min · Pairs

Pairs Activity: Spring Constant Comparison

Test two springs with identical masses. Measure extensions, compute k and E_e for each. Compare how material differences affect energy storage. Graph results to visualize relationships.

Design a system that uses elastic potential energy to launch a projectile.

Facilitation Tip

In the spring constant comparison activity, assign each pair a different spring so they present their k values on a class chart for comparison.

What to look for

Pose the question: 'Imagine you are designing a catapult to launch a marshmallow the furthest distance. What factors related to elastic potential energy would you consider, and how would you adjust them to maximize the launch distance?' Facilitate a class discussion on spring stiffness, displacement, and energy transfer.

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

Activity 04

• Stations Rotation
• 40 min · Whole Class

Whole Class Demo: Energy Conversion

Demonstrate a spring launcher with motion sensor. Class predicts kinetic energy from E_e, then verifies with velocity data. Discuss conservation and losses in a shared spreadsheet.

Explain how elastic potential energy is stored in a compressed or stretched spring.

What to look for

Provide students with a spring, a set of masses, and a ruler. Ask them to measure the extension of the spring for three different masses, calculate the spring constant 'k' for each trial, and determine the average spring constant. Then, ask them to calculate the elastic potential energy stored in the spring when stretched by 0.10 m.

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

A few notes on teaching this unit

Start with a short demonstration of stretching a spring to show how force changes with displacement. Emphasize that energy calculations require squaring the displacement, which students often miss. Avoid letting them rely solely on formula memorization; instead, connect each calculation to their lab data. Research shows that students grasp quadratic relationships better when they generate their own graphs and analyze trends before applying formulas.

Students will accurately measure spring extensions, calculate spring constants, and compute elastic potential energy using E_e = ½ k x². They will explain how stiffness and displacement affect energy storage and recognize the difference between linear force and quadratic energy relationships. Evidence from graphs and calculations will show their understanding of energy conversion processes.

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Watch Out for These Misconceptions

• During Hooke's Law Verification, watch for students assuming elastic potential energy scales linearly with displacement like gravitational potential energy.

  Have students calculate E_e for each data point they collected and plot it against x. Point out that their graph will curve upward, showing the quadratic relationship they derived from ½ k x².

• During Spring Constant Comparison, watch for students assuming all springs have the same spring constant k.

  Have groups present their k values and explain how material thickness, coil spacing, or wire gauge affected their results. Use the class chart to highlight the range of stiffness values.

• During Energy Conversion whole class demo, watch for students thinking stored elastic energy is entirely lost as heat when released.

  After launching the projectile, measure its range and compare it to the calculated initial energy. Lead a discussion on where minor energy losses occur and how efficiency could be improved.

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Methods used in this brief

• Stations Rotation