GCSE Physics (AQA)

346 videos | 23 hours

Principle of Moments

Please subscribe to watch this video.

This, and all other videos, are included in our premium subscriptions.

Premium accounts get access to all videos.

Forces Moments, levers and gears

Principle of Moments

4:15 Moments
Spec 4.5.4
Previous Calculating Moments Next Using Principle of Moments
  • The principle of moments states that a system is balanced when the total clockwise moment equals the total anti-clockwise moment about its pivot.
  • A moment is the turning effect caused by a force, depending on the force's size and distance from the pivot.
  • The principle of moments determines when moments cause an object to turn or not.
  • This principle is crucial for scales to check if two weights are equal.
  • A weight on the right scale creates a clockwise moment, while a weight on the left creates an anti-clockwise moment.
  • If scales don't tilt, the moments are equal, indicating balance.
  • The principle of moments is important in exam questions about moments.
  • Situations with more than two forces contributing to a moment can be analyzed using this principle.
  • Multiple forces acting on an object create individual moments around a pivot.
  • Total moments in clockwise and anti-clockwise directions can be summed up.
  • The object rotates in the direction of the greater total moment.
  • If total moments in both directions are equal, no rotation occurs.
  • Forces causing clockwise and anti-clockwise moments can cancel each other out, resulting in no rotation.
  • The principle applies similarly to forces where equal and opposite forces cancel each other out.
  • When total moments in both directions are equal, the resulting moment is zero, and the object does not rotate.

Please subscribe to access these revision notes.

This, and all other video notes, are included in our premium subscriptions.

Premium accounts get access to all videos and revision notes.