Good Riddles

Question: What is as big as you are and yet does not weigh anything?

Question: My name is Ruger. I live in a farm. There are four other dogs in the farm with me. Their names are Snowy, Flash, Speed, and Brownie. Who is the fifth dog?

Question: Without me, nothing exists. What am I?

Question: I am there !!! but I was!!!

Question: What sandwich can tell where you are and what you are eating?