Grade Level: Middle School
Subject: STEM - Engineering and Physics
Time: 60-90 minutes
Objectives:
Understand basic principles of force, motion, and energy.
Apply engineering skills to design and construct a rubber band-powered car.
Test and evaluate the performance of the car through hands-on experimentation.
Materials (per student or group):
Cardboard (approx. 6"x4" for chassis)
2 plastic lids (for wheels)
2 straws (for axles)
2 rubber bands
Scissors
Tape or glue
Skewers or thin dowels (optional for stronger axles)
Key Vocabulary:
Potential Energy: Stored energy in the rubber band when stretched.
Kinetic Energy: Energy of motion when the car moves.
Axle: A rod that allows wheels to spin.
Chassis: The base structure of the car.
Step-by-Step Instructions
Introduction (10 minutes):
Discuss the basic physics of how a rubber band-powered car works. Explain the concept of potential energy in a stretched rubber band and how it converts to kinetic energy when the rubber band is released.
Show an example or diagram of a simple rubber band-powered car.
Design the Chassis (15 minutes):
Cut a piece of cardboard to serve as the chassis (approx. 6"x4").
Make sure it’s sturdy enough to hold the wheels and axles.
Prepare the Wheels and Axles (10 minutes):
Punch holes in the center of each plastic lid to create the wheels.
Insert straws through the holes in the cardboard chassis to act as axles.
If using dowels or skewers, cut them to fit the straws and slide them through for more stability.
Attach the Wheels (10 minutes):
Attach the plastic lids to the ends of the straws or skewers. Ensure the wheels spin freely but are secure on the axles.
Test that the car rolls smoothly.
Add the Propulsion Mechanism (15 minutes):
Secure one end of the rubber band to the back axle by taping or hooking it.
Twist the rubber band around the axle a few times.
Pull the car backward, which stretches the rubber band, storing potential energy.
Test and Adjust (15 minutes):
Release the car and observe how it moves.
Allow students to make adjustments to improve speed or distance. They can experiment with more or fewer twists, different wheel sizes, or axle positioning.
Reflection and Discussion (10 minutes):
Discuss what worked well and what could be improved.
Talk about how the design could be changed to increase efficiency or performance.
Relate this activity to real-world engineering and vehicle propulsion systems.
Assessment:
Observe the construction process and ensure students understand the key concepts.
Have students explain the role of potential and kinetic energy in their cars.
Assess their ability to problem-solve and make improvements to their designs.
Extensions:
Challenge students to modify their cars to make them go farther or faster.
Have students calculate the distance traveled and the number of twists required for optimal propulsion.
Experiment with different materials for wheels, axles, or chassis to see how they affect performance.
This lesson introduces students to basic engineering and physics concepts while giving them hands-on experience with design and testing.