What Am I Riddles

Question: I'm one. but I can overcome ten with one swing and a spin . What am I?

Question: What beats but inflicts no pain?

Question: I move around yet one side is hidden while another is shining. I can be seen full but only sometimes. What am I?

Question: Turn us on our backs and open up our stomachs You will be the wisest. What am I?

Question: The more you cut into me the bigger I grow, what am I?