I agree with that simple law of physics. It is also possible for an Ion Drive to accelerate a space ship to speeds of over 100,000 miles per hour. But not at a practical rate of acceleration.
The problem I think many engineers are faced with today is the fact that they are trying to convert mechanical energy into electrical energy then turning it back into mechanical energy. The loss of efficiency is predictable and difficult to overcome.
The problem I think many engineers are faced with today is the fact that they are trying to convert mechanical energy into electrical energy then turning it back into mechanical energy. The loss of efficiency is predictable and difficult to overcome. But the method by which chemical energy becomes mechanical energy is very important.
Gasoline powered IC engines have poor efficiencies of around 25%, even though they convert chemical energy directly to mechanical energy.
But a coal burning plant might have an efficiency of between 36% and 48%. Even assuming 10% line loss means you get 33% to 43% efficiency at the electrical socket. Another 10% loss in the car's electric motors and you still are ahead on efficiency. And all the while burning a cheaper fuel.
And some power plants with gas fired turbines reach up to 60% efficiency!