Review the topic of friction as a force, the measurement of and direction of action. Determination of net force when thrust and friction are given, as well as air resistance being a form of friction. The determination of the acceleration of a heavy object and a light object being dropped from a height, and showing that both have the same acceleration due to the ratio of force to mass in free fall always equaling the gravitational force of 9.8 Newtons. The idea of terminal velocity being reached when air resistance equals the weight of the object due to acceleration no longer increasing was presented and discussed.