Describe the experimental procedure that was used and the results obtained. Have the students give their statements regarding Newton's First Law of Motion. Then show portions of the Mechanical Universe tape Inertia. If they have any parlor tricks that demonstrate the first law of motion have them do them or at least describe them. A force had to act on an object to change the motion.
Students begin motion as soon as the frictional force is diminished by the air.
Any slight motion will produce an unbalanced force that will start them moving. Acceleration of an object increases as the force causing the acceleration increases. For a given force the smaller the object the faster its speed changes. Students very often do not understand the term acceleration. They will memorize the definition, but have no physical understanding for the term.