How would Newtons laws of motion apply to a leaf that is being blown away by the wind?

The wind is blowing with so much force that the leaf doesn't have enough strength to withstand it, therefore the wind slows down a little but still retains its forward motion.

Another example is when you punch a brittle wall. If you hit it with enough force it will break and your fist will go through and keep its forward motion, albeit a little slower.