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.
Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones.here the plates meet, their relative motion determines the type of boundary: convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates typically ranges from zero to 100 mm annually.