A semi has typical dimensions (2.6m wide, 4.1 m high, 16 m long). Assume the drag coefficient is 0.55. Assume the rolling friction to be 490 Newtons. A diesel engine efficiency is higher than other vehicles, so assume an efficiency of 0.3. These vehicles are also restricted to lower speeds (let's say 27 m/s). At that highway speeds of 27 m/s, calculate the ratio of rolling friction to drag force. Calculate the total force and estimate the effective miles/gallon of a fully-loaded tractor-trailer on a flat highway.

A semi has typical dimensions (2.6m wide, 4.1 m high, 16 m long). Assume the drag coefficient is 0.55. Assume the rolling friction to be 490 Newtons. A diesel engine efficiency is higher than other vehicles, so assume an efficiency of 0.3. These vehicles are also restricted to lower speeds (let's say 27 m/s). At that highway speeds of 27 m/s, calculate the ratio of rolling friction to drag force. Calculate the total force and estimate the effective miles/gallon of a fully-loaded tractor-trailer on a flat highway.