The combat controller training program is as follows: Combat Control Screening Course, Lackland Air Force Base, Texas This 10-day screening course focuses on physical fitness with classes in sports physiology, nutrition, basic exercises, CCT history and fundamentals. Combat Control Operator Course, Keesler AFB, Miss.
Static or dynamic friction always act in a direction opposite to the impressed force. The dynamic friction does not need in any force. It is realy directed in opposit to the velosity. And the static friction can never be without the shearing force and it is always directed in opposit to it. However, you are right - dynamic friction forces can or slow down the movement of the body or accelerate it.
The force of friction acts in opposition to motion. Therefore it is the force of friction which must be balanced in order to keep an object in motion in a constant velocity. Without friction, an object in motion at constant velocity would remain so unless acted upon by an unbalanced force.