Something that just happened- I was at church today for our church work day. I was helping someone else work on the flower-bed. We were trying to lift an extremely heavy concrete block (a parking barrier) and all we had were 2 crow-bars. I had the hook end of the bar down below the concrete block. Suddenly God spoke to me and said to position my hands at the far-end of the bar (towards the straight end) for greater mechanical advantage. I did this and we were able to lift the block! Mechanical Advantage is an engineering concept and what the voice said was right-on according to the laws of physics! Maybe you already knew about this but I did not! Mechanical Advantage is a measurement of the force amplification of a hand-tool and this is how a crowbar and also a fire axe works, the formula is:

MA=Output Force/Input Force