Vectors & Scalars
Pre-lecture Video
This takes DC about 9 minutes to deliver.
- Start with verbal definitions
- Define scalar (physical quantity represented by just a number)
- Give examples (mass, volume, and density)
- Define vector (physical quantity represented by number and direction - size and orientation)
- Give examples (velocity (traveling along Grand River to the east at 40 mph), accel, forces)
- Picture of a vector
- Similarity of two vectors
- Mathematical representation in 3D
- Components of the vector (how much of the vector is in each direction)
- Shift to 2D vector (easier to draw)
- Graphical representation (draw big)
- Vector components can be measured from reference point (origin or elsewhere)
- Mathematical representation
- Magnitude can be computed (Pythag)
- Orientation can be computed (trig, defined from +x; so be careful)
- Can also get components from mag and orientation (trig, defined from +x, so again be careful)
- Finally, adding and subtracting vectors
- Graphically, tip to tail method (show addition)
- Mathematically, add or subtract scalar components (show addition)
- Some additional notes are online including unit vectors and vector subtraction
Possible Conceptual Homework
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- 1-2, 1-3, 1-4, 1-5