# Velocity

Pronunciation: /vəˈlɒs.ɪ.ti/ Explain

Both velocity and speed both answer the question, "How fast?". Velocity and speed are measure of change in distance relative to time. If a automobile is in Salt Lake City, Utah at 3:00 PM, and goes 40 km to Orem, Utah arriving at 3:40 PM, the average speed of the automobile is 40 km / (40 minutes) = 40 km / (2/3 hours) = 40 × 3/2 kph = 60 kph. Acceleration is defined as the rate of change of velocity or direction with respect to time.

By convention, the word 'velocity' is usually used in the sciences and mathematics. The word 'speed' is usually used on other occasions.

### References

1. McAdams, David E.. All Math Words Dictionary, velocity. 2nd Classroom edition 20150108-4799968. pg 189. Life is a Story Problem LLC. January 8, 2015. Buy the book

McAdams, David E. Velocity. 5/13/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. https://www.allmathwords.org/en/v/velocity.html.

### Revision History

5/13/2019: Changed equations and expressions to new format. (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
12/17/2018: Removed broken links, updated license, implemented new markup. (McAdams, David E.)
8/7/2018: Changed vocabulary links to WORDLINK format. (McAdams, David E.)
6/7/2008: Corrected spelling. (McAdams, David E.)
4/16/2008: Initial version. (McAdams, David E.)

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