FREE-BODY DIAGRAMSApplication of Newton's LawsCP-04 Page 8Rev. 0Figure 3 Free-Body DiagramThe frictional force (F ) is a force that opposes the direction of motion. This force isKexplained in more detail in the chapter on types of forces.To solve this practical problem, the student would assign values for each force as determinedby data given in the problem. After assigning a sign convention (e.g., + for forces upward andto the right, - for forces downward and to the left), the student would sum all forces to findthe net force acting on the body. Using this net force information and appropriate equations,the student could solve for the requested unknowns. A variation would be to have thestudent find an unknown force acting on the body given sufficient information about the otherforces acting on the body. The student will learn to solve specific examples using free-bodydiagrams in a later chapter.Some advanced free-body diagrams for various types of systems are shown in Figure 4.