# Moment of Force==Moment of Inertia?

**URL:** <https://boards.straightdope.com/t/moment-of-force-moment-of-inertia/118390>\
**Category:** Factual Questions\
**Created:** [July 11, 2002, 10:04am UTC](https://boards.straightdope.com/t/moment-of-force-moment-of-inertia/118390 "2002-07-11T10:04:57Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Cubsfan](https://avatars.discourse-cdn.com/v4/letter/c/f4b2a3/32.png) [@Cubsfan](https://boards.straightdope.com/u/Cubsfan)\
**Post date:** [July 11, 2002, 10:04am UTC](https://boards.straightdope.com/t/moment-of-force-moment-of-inertia/118390/1 "2002-07-11T10:04:57Z")

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I am doing an ind study Statics and Dynamics class for my undergrad EE. In my book it keeps referring to “the moment of force”. I understand what it is. I just want to make sure that it is the same as “Moment of inertia” that I remember from Physics 211.

On a side note, I know I am gonna have alot of little questions like this since I am independent studying this course and it is not practical for me to post every question I have on this board. The board wouldnt like it either. Since there seems to be only a select group of folks who have a solid enough understanding of this subject matter to explain stuff to a layman like myself would anybody be willing to answer basic questions via email if they have the time?

I am not looking to have someone teach me SnD via email, but if one or more of the geniuses on this board have the time I would love to pick your brains when I am not understanding certain concepts from the book. The book I have is “Vector Mechanics for Engineers 5th ed Beer/Johnston”. It seems to be the standard for most schools. If you have that book I can just say “In example such and such on page such I dont get this thing”.

I promise I wont bug too much, but I dont wanna post a question and have it sink into the SDMB abyss before someone can answer it.

Let me know if you are willing and I will email you! My email address that I set up this account with has been spammed to death so I dont even check that one. Thank you!

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**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\
**Post date:** [July 11, 2002, 12:22pm UTC](https://boards.straightdope.com/t/moment-of-force-moment-of-inertia/118390/2 "2002-07-11T12:22:54Z")

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Moment of inertia is not the same as the moment of force. Moment of inertia is the rotational equivalent of mass; moment of force (AKA torque) is the rotational equivalent of force. Just as F = m a, Moment of force = moment of inertia times the angular acceleration.