My Balloon Car assignment

This is my Balloon car design, We designed balloon cars on Tinkercad and tested how far they would roll when we attached a balloon on the back of it. After our first test we could work in pairs to make a better and improved model of our balloon car. My first model of balloon car went 4 millimeters and my second card went 11 millimeters. My first car struggled with the wheels being too loose so i tightened them on the second car I made, So the car went further.