Answer:
I am the key that is the hardest to turn
I have a head tail but no arms and legs.
Everyone asks for me but yet everyone hates to face me. For someone I am agony, for others I am relief! What am I?
I am gentle enough to soothe your skin light enough to fly in the sky and strong enough to crack rocks.
As a state in America I am round on both sides and high in the middle.
I met a man on the London bridge, he tipped his hat and drew his name, in this riddle I told you his name. What is it?