I have a physical Bitcoin, how can I exchange it for dollars I aquired a Bitcoin back in 2013,can I exchange it for dollars at a bank.
There are a handful of people/companies who manufactured physical bitcoins, most notably Casascius.

If you have one of these, a little tamper proof seal should cover a private key. You can then import that private key into a wallet such as electrum, and send the bitcoin to an exchange where you can trade it for fiat, which will vary by your location. 

If you do not have a bitcoin which contains a private key, then your physical bitcoin has no bitcoin value.