The moment (turning effect)

• December 3rd, 2005, 09:49 AM
almirza
The moment (turning effect)
Another question friend ,

If we have a ruler and there are 2 forces acting on it . One on the left side and the other on right side . One acts upwards and the other downword( I mean not in the same line of action ) . This will make the rular rotate. Even the 2 forcec are equel in size it will rotate . And also if the forces are not equel it will rotate . But what is the diffrence in rotating in the 2 cases???????????!!!!!!!!!!

Assume they are at the same distance from the pivot.
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• December 3rd, 2005, 12:45 PM
mitchellmckain
The difference is that if the two force are not equal then there is a net force on the object and the ruler will move in the direction of the net force in addition to rotating.

This will also happen if the two forces are equal but not in completely opposite directions. But with only two forces they must be both equal in magnitude and opposite in direction in order to cancel each other out so there is no net force. The rotation comes from the fact that the forces are not applied directly behind the center of mass so there is a lever arm and a resultant torque.