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## #1 2013-08-21 19:54:28

AlbertMThomas
Member
Registered: 2013-08-21
Posts: 9

### Statics Problem...

A light triangular plate OAB is in a horizontal plane. Three forces, F1=4N, F2=12N, and F3=4N, act on the plate, which is pivoted about a vertical axis through point O. Find the torque (or "moment") of force F1 about the axis through point O.

I don't understand :"Find the torque (or "moment") of force F1 about the axis through point O"

Last edited by AlbertMThomas (2013-08-21 19:55:07)

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## #2 2013-08-21 21:21:06

bob bundy
Registered: 2010-06-20
Posts: 8,082

### Re: Statics Problem...

hi

F1 is trying to cause a rotation around O.

the moment of the force is the product of the size of the force times the perpendicular distance from O to the line of action of the force

You can use trig to get d.

Bob

Sometimes it is easier to split F1 into a horizontal component (F1cos30) and a vertical component (F1sin30) and then get the moment of each.

As the vertical component acts through O it will have zero moment.

If you do it this way you'll get the same answer so it would be worth trying both just for the practice.

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #3 2013-08-21 22:04:01

AlbertMThomas
Member
Registered: 2013-08-21
Posts: 9

Thanks

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