I'm taking "physics for engineers" right now - the condensed 4 hour summer course over 7 weeks. I'm doing fine in the class. I feel confident about the ideas and concepts we've covered so far, sure enough, but I'm having a hard time grasping the concept (geometrically at least) of the scalar/dot product. Certainly ABcos(ø) is simple enough to calculate. And I understand I'm getting a scalar, rather than a vector, so there isn't going to be an actual geometric representation of the number calculated... but... what is it? For example if we have two vectors, A & B, and we say that A runs along the x-axis in the positive direction and has a magnitude of 4, and we have a vector B that runs 77° from A with a magnitude of 5 (that is to say B is in the first quadrant, between the x and y axis, but closer to the y axis.) then we have the following: cos = 4.5 What is the 4.5 representative of? A magnitude of a non-existent vector? The force one vector applies to another?