Post History
#2: Post edited
by
Agent Smith
·
2023-09-22T16:33:57Z (8 months ago)
- You need to:
- 1. Explain what a scalar is (pure magnitude)
- 2. Explain what a vector is (magnitude & direction).
- As you've drawn the diagram, your intention is clear. $\vec b - \vec r$ (in red) has been labelled (in)correctly (no arrows over b and r). You also wish to emphasize that $|\vec b| - |\vec r|$ (green) is about magnitude by putting both vectors in the same direction.
However, the vector $\vec r$ in $\vec b - \vec r$ is NOT the same as the $vec r$ in $|\vec b| - |\vec r|$ (different directions). In a sense what you've done is eliminate the differentiating feature of a vector (direction) by doing this and so students will mix up $\vec b - \vec r$ and $|\vec b| - |\vec r|$.
- You need to:
- 1. Explain what a scalar is (pure magnitude)
- 2. Explain what a vector is (magnitude & direction).
- As you've drawn the diagram, your intention is clear. $\vec b - \vec r$ (in red) has been labelled (in)correctly (no arrows over b and r). You also wish to emphasize that $|\vec b| - |\vec r|$ (green) is about magnitude by putting both vectors in the same direction.
- However, the vector $\vec r$ in $\vec b - \vec r$ is NOT the same as the $\vec r$ in $|\vec b| - |\vec r|$ (different directions). In a sense what you've done is eliminate the differentiating feature of a vector (direction) by doing this and so students will mix up $\vec b - \vec r$ and $|\vec b| - |\vec r|$.
#1: Initial revision
by
Agent Smith
·
2023-09-22T14:23:37Z (8 months ago)
You need to: 1. Explain what a scalar is (pure magnitude) 2. Explain what a vector is (magnitude & direction). As you've drawn the diagram, your intention is clear. $\vec b - \vec r$ (in red) has been labelled (in)correctly (no arrows over b and r). You also wish to emphasize that $|\vec b| - |\vec r|$ (green) is about magnitude by putting both vectors in the same direction. However, the vector $\vec r$ in $\vec b - \vec r$ is NOT the same as the $vec r$ in $|\vec b| - |\vec r|$ (different directions). In a sense what you've done is eliminate the differentiating feature of a vector (direction) by doing this and so students will mix up $\vec b - \vec r$ and $|\vec b| - |\vec r|$.