Physics or Animation?

Was just curious about the basic rule of thumb on when to use Physics or animations?

For example a wind mill, would you animate the rotating motion or use the phyiscs engine with wind to make this move.

If the movement is fixed I would use animation, otherwise physics.

I think this question belongs in the forum because it’s not a yes or no answer, it depends on your game needs.

In case of your windmill I think it will be better to use the animation than physics engin because aniamtion is light weight than physics unity engine will use less effort to make animation than physics