Final answer:
The percentage of power converted from exhaust gases to shaft horsepower for propellers depends on the engine efficiency, commonly 15-25% for cars and 30-40% for power plants, with variations in maritime applications like nuclear submarines.
Step-by-step explanation:
The percentage of power derived from exhaust gases that is converted to shaft horsepower to drive a propeller depends on the efficiency of the engine. While the question does not provide specific engine types, we can consider general efficiencies for heat engines. For example, a typical car engine has an efficiency in the 15-25% range, whereas electrical power plants operate at about 30-40% efficiency. However, these efficiencies pertain to the conversion of heat into usable work, and specific figures for engines converting exhaust gases to propeller thrust would depend on the type of engine and the conditions under which it operates. In maritime applications, such as with nuclear submarines, efficiencies will differ due to different engine designs and the use of turbines connected to propeller systems.