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Walter & Group...
[GH] Mia Culpa !
Yesterday, in my answer to Troy Miller, I wrote: "We must be careful not to assume that our casting students will really understand the difference between scalar quantities such as "speed" and "velocity" and vector quantities such as "acceleration". Many very competent instructors have a fuzzy idea of those differences "
This should have read :
"We must be careful not to assume that our casting students will really understand the difference between scalar quantities such as "speed" and vector quantities such as "velocity" and "acceleration......"
Interesting that when I double checked that in Webster's Unabridged Dictionary, I found a contradicttion :
Velocity 1. rapidity of motion or operation, swiftness; speed
2. mech. the time rate of change of position of a body in a specified direction. *
Definition 1. uses the word "speed" as a synonym for "velocity" which would make it seem that both are non directional and, therefore, scalar quantities. (Common usage).
Definition 2. makes it clear that when the word "velocity" is used in the mechanical sense, that it is directional movement and, therefor, a vector quantity.
Just another example of some of the problems we face as we try to come up with definitions ranging from the strictly scientific to those in common language.
For this reason, some have suggested that glossary committees might do well to take the dictionary approach to the listing of definitions. Of course, this would result in more than one definition for each entry.
* Webster's Unabridged Dictionary
Gordy
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