How do I Build a Coke & Mentos Car?

Theory

• When Mentos mints are added to a warm bottle of soda, it causes a sudden generation of carbon dioxide that must exit from the bottle, creating a fountain. Instead of placing the bottles vertically, they can be placed horizontally against a solid object and propel a vehicle forward a short distance.

Bottle Setup

• The bottles must be fitted securely to the car, with a delivery system created to place the Mentos into the bottles simultaneously. Each bottle should be connected to a hollow pipe and inside that pipe is a rod that the liquid will want to push out when the Mentos are added. This should be one single apparatus. The entire mechanism should then be attached to a three- or four-wheeled motorless vehicle frame. It should be lightweight and consist of a frame, wheels and a steering mechanism.

Execution

• Place the car against a solid object such as a wall and secure it using a brake that can be lifted manually by a lever. When the Mentos are added to the Coke, they will want to push the rods out of the pipes, but the wall will keep them from being pushed out, causing a build-up of energy. Release the hand brake, and the rods will shoot from the pipes along with the soda, propelling the car forward.

Warning

• The Coke/Mentos reaction can create a large amount of energy. The bottles should be secured tightly to the apparatus and the apparatus should be secured tightly to the car. If not, the bottles could become loose and shoot out like rockets, or the apparatus could become dislodged from the car.