Lesson Title: LEGO Racing Cars Challenge: Exploring Speed, Friction, and Energy Transfer
Grade Level: Middle School (Grades 6-8)
Duration: 1-2 class periods (45-60 minutes each)
Objective:
Students will build LEGO cars using pullback motors and race them on a straight track. Through experimentation, they will learn about concepts such as speed, friction, and energy transfer, while optimizing their car designs for maximum speed and stability.
LEGO sets (including wheels, axles, and various bricks for building)
LEGO pullback motors
Measuring tape or rulers
Stopwatch or timer
Paper and pencils for design sketches and data recording
Smooth track (3-5 meters in length) for racing (can use a long table, the floor, or specific track material)
Optional: various surface materials for additional experiments (carpet, rough sandpaper, etc.)
Speed: The distance an object travels over time.
Friction: The force resisting the motion of an object.
Energy Transfer: The pullback motor stores energy that is released to make the car move.
NGSS MS-PS3-1: Apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer.
NGSS MS-ETS1-4: Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.
1. Introduction (10 minutes)
Warm-Up: Begin with a brief discussion on how cars move, asking students if they have ever thought about what makes cars go fast or slow.
Introduce Key Concepts:
Discuss speed, friction, and energy transfer.
Explain how the LEGO pullback motor stores energy (potential energy) when you pull it back, and how it releases this energy to make the car move (kinetic energy).
Real-World Connection: Mention real-world applications such as drag racing, car design, and how engineers optimize vehicles for speed.
2. Building the LEGO Cars (20-25 minutes)
Instructions: Each student (or small group) will build a LEGO car powered by the pullback motor.
Provide guidelines on basic car structure, including wheels, axles, and the pullback motor.
Encourage students to think about car size, weight distribution, and stability to optimize for speed.
Sketch Designs: Before building, have students sketch a rough design of their car and identify the factors they think will affect speed (e.g., wheel size, weight distribution).
3. Racing and Data Collection (15-20 minutes)
Track Setup: Use a smooth, flat surface as a race track.
Race in Rounds: Have students race their cars in multiple rounds, recording the time it takes for each car to complete the track using a stopwatch.
Measure Distance: In cases where cars do not reach the finish line, students should measure how far the car traveled.
Data Recording: Students should record their results (time, distance traveled, observations about stability, etc.) in a table.
4. Experimentation and Modification (15-20 minutes)
Discussion: After the first set of races, discuss the results as a class:
Which cars were fastest? Why?
What role did friction play (e.g., from the surface or the wheels)?
How did the car's weight or design impact speed and stability?
Modifications: Allow students time to modify their designs based on what they learned (e.g., adjusting weight distribution, changing wheel size, or lowering the car's center of gravity for stability).
Second Round of Racing: Race the modified cars and record results to compare with the original designs.
Analyze Data: Students compare their before-and-after data to evaluate the effect of their modifications on car performance.
Class Discussion:
Which designs were most successful? Why?
How did friction affect the car’s performance?
What design features helped transfer energy most efficiently to speed?
6. Closing and Reflection (5-10 minutes)
Reflection Questions (can be done in writing or group discussion):
What did you learn about how friction and energy transfer affect car speed?
What changes would you make to your car design if you had more time?
How do engineers use similar experimentation in real-world car design?
Formative: Observation of students during building and racing, participation in discussions.
Summative: Students submit their design sketches, data tables, and a brief reflection on how their car design evolved and the impact of modifications on performance.
Advanced: Challenge students to experiment with different surfaces (e.g., carpet, rough floors) to explore how surface friction impacts car speed.
Simplification: If time is limited, focus on the racing aspect with minimal modification, but emphasize key concepts in a group discussion.
This lesson will engage students with hands-on learning while reinforcing critical STEM concepts in a fun and competitive format.