PLAINS - Sixth grade students got out of the classroom and into the Plains High School gym lobby to try out their designs for a self-propelled car, a project that combined physics, engineering and structural design.

Constructed of plastic sheeting, wooden wheels, strings and weights, the cars used gravity, levers and a string wound around the rear axle to propel the car forward. While designs varied slightly from team to team, the essential elements remained constant.

Originally conceived around the year 1478 by none other than Leonardo da Vinci, the “gravity cruiser” car is designed to utilize simple on board mechanisms to provide thrust. While the materials may have changed since da Vinci’s day, the basic concepts are the same as they were in the 15th century.

A string is wound around the rear axle and attached to a lever that is connected to a vertical support mounted to the chassis of the car. A weight is placed at the front of the lever and when released, the weight causes the lever to drop forward. The string connected to the rear of the lever is pulled upward, unwinding around the axle. This action causes the axle to turn thereby propelling the car forward under it’s own power.

Sixth grade teacher Lisa Brown received training on implementing the project last winter in Helena and said, “The project is a great way for the kids to learn about science. They’ve worked really hard on this project and now we are in the test phase. The gravity car is the final project of our unit in physics that focused on simple machines and Newton’s laws of motion.”

Distances of 15 feet were routinely attained amid smiles of accomplishment and pride in a job well done. Teams will go on to demonstrate their grasp of da Vinci’s concept in front of the Plains school board after completion of the test phase and graphing the results.