I am studying projections and their applications in physics; specifically, using projections to calculate work.
In Stewart's Early Transcendentals, he explains that the work done by the force is defined to be the product of the component vector of the force along D and the distance moved.
Now, I interpreted the component vector of the force along D to be the scalar projection of F onto D. However, in figure 6, it is depicted as a vector projection (pink line). Am I missing something or is this a small oversight in the textbook?
For reference, this is how scalar and vector projections are depicted in the textbook.