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Is there a negative velocity? if so how is it achieved?

Velocity has two components, speed and direction. Speed can be measured in whatever units you like, say miles per hour. Direction is defined by the person doing the measurement. So, if I define one direction to be positive I will have a positive velocity when travelling in that direction. I will have a negative velocity when travelling in the opposite direction.

The point is: you cannot have a negative _speed_ many physical quantities, BY DEFINITION, cannot be negative some examples: speed, mass, measurements of size, the direction of time, temperature (in the Kelvin scale),... extra credit: think of some more things that cannot be negative

John Hawley

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