AC falling, why MC below AC curve?

Question

when AC are falling, why is MC below AC curve?

could you explain so that it's easy to understand?

Answer 1

AC is total average cost for production of units

MC is the addition made to produce one more unit

in long run the total cost for producing a unit reduces eventually so does the AC curve

MC also reduces but more than the ac curve

Answer 2

The MC is simply the cost of making one more product.  If the cost of making that one product is below the average, it will pull the average down.