eli5: Can any engineers explain second moment of area intuitively?

Question

eli5: Can any engineers explain second moment of area intuitively?

In: 5

Answer 1

If you have a 2×4 beam and try to bend it so the 2 is the depth it is easier to bend than if the 4 is the depth. The reason being is because the bending moment you are applying is distributed across 4 inches rather than 2, it’s like if you have a pole on a rectangular base that is 2 foot by 4 foot it’s easier to push it over if you push it in the two foot direction rather than the four foot direction.