What is the efficiency for the energy that could be obtained by dropping an object onto a table top relative to the ground as a reference level ?

Work Done:

Efficiency:

• The maximum efficiency is measured relative to some base line reference point.
  
• Thermal Reference Point = Absolute Zero
  
• If you are only allowed to drop objects onto the surface of the table you can never get 100% of the energy you could get if you could drop them onto the floor.
  
• If you cannot lower the exhaust heat temperature to absolute zero then you will never be able to get 100% of the energy you could get if you have the heat sink at absolute zero.