Balanced Moments and Stability.

If someone weighs 300N and sits 2m from the pivot of a seesaw, and you weigh 700N, how far would you need to sit?

300*2=700*x -----> 300*2/700=x----->x=0.86, so 86cm away from pivot. 

It could also be worded with the word tension, but the tension force is what is balancing the "seesaw"

The object will turn. If the total anticlockwise moments do not equal the total clockwise moments, there will be a resultant moment

Unstable objects tip over easily. Stable ones don't. Position of CoM is important. 

Stable objects have wide base&low centre of mass.

An object will tip if the CoM is outside the width of its base.

If the weight doesn't act in line with the pivots, it will cause a resultant moment