After exploration of how objects fall, and the impact they have on other objects using the computer program called Contraption Maker, students will be asked to build a certain size model that a ball can travel through at the slowest speed possible.  They will pick a manufacturing process of a favorite toy and create a model of a section of an assembly line.  Through trial and error, students will find that creating collisions, changing directions and controlling the slope will slow the speed of the production.  They will measure the model to make sure it is at the required height and length using customary units.   Through the engineering process of trial and error, they will adjust their model because the slowest time will win the competition.  Students will do a final run of their model while timing the passage of the ball.  Students will engage in a math lesson converting units from inches to feet to miles and from seconds to minutes to hours.