In physics, when a constant force acts on an object as the object is displaced, the work...

In physics, when a constant force acts on an object as the object is displaced, the work done by the force is the product of the length of the displacement and the component of the force in the direction of the displacement. Figure 1.48 depicts an object acted upon by a constant force F, which displaces it from the point P to the point Q. Let θ denote the angle between F and the direction of displacement. (a) Show that the work done by F is determined by the formula (b) Find the work done by the (constant) force F = i + 5j + 2k in moving a particle from the point (1,−1, 1) to the point (2, 0,−1).