What is the difference between a productive and a unproductive cough?

Unproductive cough doesn't bring anything (sputum) up during the coughing process. A productive cough, sputum will be brought up from the lungs.

35 cubic feet of dirt if it's digging a burrow

You did not show us the image of the burger, but i shall try to answer as best i can.  when purchasing food, always consider the ingredients as well as the person who prepared it. consider if they were hygienic people or not, in case the burger was infected with bacteria. no mortal should place an infected burger into their mouth.