Math Is Fun Forum

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"

Please solve with steps

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

Bob

Administrator

Registered: 2010-06-20

Posts: 10,163

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.

---

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Sometimes I deliberately make mistakes, just to test you!  …………….Bob

AlbertMThomas

Member

Registered: 2013-08-21

Posts: 9

Re: Statics Problem...

Thanks