I am easy to feel but hard to see
Can you guess what I might be?
I'll give you hints to ease your mind
And help you solve this little rhyme

Let's begin with clue number one
I cause so much damage before I'm done
Wrecking homes and destroying power
I can be gentle and than turn sour

I can wreck ships with my force
Or cause them to change their course
Others use me for their pleasure
When I am behaving much better

I bring children lots of fun
When they take their string and run
There objects hang for all to see
Defying the law of gravity

Still I have a different use
One that I can not refuse
I keep the power at a flow
With the way my blades always go

I have given you lots of clues
And now my time is past due
Before I leave and say good by
Please tell me what am I?