Momentum and Newtons Laws

Moments

 * Moments are all about the clockwise/anti-clockwise turning effects caused by forces around a pivot point. If the force is at a greater distance from the pivot point the turning effect will larger. The moment the acts on an object can be calculated by using the equation M = F x D, where F is the magnitude of the force in Newtons, and D is the perpendicular distance from the pivot where the force is acting in Metres. Therefore the units we use for moments are Nm. If the force is not acting perpendicular you can use trigonometry to find the magnitude of the force that is acting perpendicular to the pivot.

Balancing Moments

 * If an object is not turning around the pivot point then the total clockwise moment acting on it must be equal to the total anti-clockwise moment acting on it.


 * Sum of the clockwise moments = Sum of anticlockwise moment

Calculating magnitude of Force

 * To find the moment of a force that isn't perpendicular to the pivot, like this one, you need to work out the component of force F that is perpendicular to the pivot point. Therefore, the perpendicular force becomes Fsin�0 and the moment becomes dFsin0 in the clockwise direction.�