Students log their experimental data and find that larger wheels allow the gravity cruiser to travel a greater distance. To investigate the effects of wheel diameter, students track their cruisers' travel distance as they attach different-sized wheels. Lesson 5: Systematic Testing: Wheel Size (45 min)-Teams use their gravity cruisers to conduct formal investigations into the effects of wheel size on vehicle performance.

Adjustments may need to be made to strengthen the tower and to make sure that the lever arm moves freely with minimal friction.

Lesson 4: Troubleshooting the Drive Mechanism (90 min)-After the preliminary testing done in Activity 3, students systematically troubleshoot their designs, working toward an overall design that performs consistently. They must also decide how to attach a string to the lever arm and wrap it around one of the axles of the chassis. This involves creating a support structure and a drive mechanism, which is a lever arm. Lesson 3: Designing and Building the Lever and Tower (120-180 min)-Students design and build an arrangement for powering the model. Using only the given materials and no direct instruction, teams build a gravity cruiser chassis that rolls freely. Lesson 2: Building and Testing a Gravity Cruiser Chassis (45-90 min)-Students are organized into teams. They are introduced to the engineering design process and the scope of this design challenge: to build a gravity cruiser, figure out how it works in order to predict its behavior, and use this knowledge to design their own customized gravity cruisers that meet specific performance goals. Students discuss the requirements described in the letter.

Lesson 1: Introducing the Gravity Cruiser (45 min)-Students receive a letter from a fictitious toy company, EarthToy Designs, inviting them to create their own gravity cruiser toy design based on specifications provided by the company. Lesson Plan Overview: Suggested 10 lessons over 15 days

Gravity design