GCSE Physics Unit 3 Revision (2)

Balanced Moments and Stability

• Balance is about whether the moments are equal
• If the anticlockwise moments are equal to the clockwise moments, then the object won't turn.
• Example 1: 
• A boy who weighs 300N sits 2m from the pivot of a seesaw.
• If another boy who weighs 700N, where should he sit to balance the seesaw?
• For the seesaw to balance, the anticlockwise moments must be equal to the clockwise moments
• anticlockwise moment = clockwise moment
• 300 x 2 = 700 x y
• y = 0.86m
• Example 2:
• A 6m long steel girder weighing 1000N rests horizontally on a pole 1m from one end.
• What is the tension in a supporting cable attached…