Learning Goal: To practice Tactics Box 5.2 Identifying Forces. The first basic step in solving force and motion problems generally involves identifying all of the forces acting on an object. This tactics box provides a step-by-step method for identifying each force in a problem. Figure1 of 1 The figure shows a crate being pulled up along an inclined board by a rope. TACTICS BOX 5.2 Identifying forces Identify the object of interest. This is the object whose motion you wish to study. Draw a picture of the situation. Show the object of interest and all other objectssuch as ropes, springs, or surfacesthat touch it. Draw a closed curve around the object. Only the object of interest is inside the curve; everything else is outside. Locate every point on the boundary of this curve where other objects touch the object of interest. These are the points where contact forces are exerted on the object. Name and label each contact force acting on the object. There is at least one force at each point of contact; there may be more than one. When necessary, use subscripts to distinguish forces of the same type. Name and label each long-range force acting on the object. For now, the only long-range force is the gravitational force. Apply these steps to the following problem: A crate is pulled up a rough inclined wood board by a tow rope. Identify the forces on the crate. (Figure 1) Part A Which of the following objects are of interest? Check all that apply. crate rope earth wood board Requ

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