The one where your host gets you privy to some vector terms and vocab.
1) Scalar- A quantity which has magnitude only, i.e. no direction. Examples: Mass, Charge.
2) Vector- A quantity which has both magnitude and direction. Vectors are usually specified as having their "tail" at the origin, and then their "tip" or terminal point is given as a coordinate, identifying both the magnitude and direction. Ex. A force [2,1] acts on a body. We assume the vector starts at the origin and points to point [2,1]. Using some trig, and the pythagorean theorem, we are able to calculate both the magnitude and direction! Usually drawn as a ray, or an arrow. The arrow point is referred to as the "tip" and the line "end" is referred to as the "tail"
3) Initial Point- The "beginning point" or tail end of the vector.
4) Terminal Point- The end point or tip of the vector. This usually denotes the direction of the vector.
5) Direction angle- Angle which describes the direction of the magnitude of the vector.
6) Component- The amount of a vector which is aligned with a particular direction, usually a coordinate axis. A vector can be described by each of its components in any coordinate system.
7) Dot Product (Scalar Product)- Operation with two vectors which returns a single scalar value. This is useful when relating a scalar value with two vector quantities. E.g.: W = F(dot)d. Work is a scalar value which is the dot product of a force vector and a position vector.
8) Cross Product (Vector Product)- Operation with two or more vectors which returns a vector value. This is useful when relating vector quantities in terms of other vector quantities. E.g. torque = force (cross) radius vector. Torque is a vector quantity.
9) Unit Vector- Vector of magnitude 1.
I think at this point we have established enough jargon that we'll be able to speak intelligently about vectors. Stay tuned next episode for Vector properties!