Engage brain and funny bone.
Some time ago an anonymous, a newbie, asked a question in a physics discussion forum, fully admitting they didn’t know the answer. Went along the lines of wind turbines on a car ought to be able to fully power it from wind and would carry on for hundereds of miles.
Image credit given later.
To the forum’s great credit this question was treated sensibly, if obviously with tongue biting about laws of thermodynamics, perpetual motions machines, yada yada. Boats came up too, they use sails.
I recall the boat with an airscrew instead of sails, worked fine if not really practical for everyday use.
Quite naturally the next tack (sic) was, well it can’t sail into the wind. Of course it can. Right into the wind. Just a matter of forces and efficiencies.
This is all about losses, efficiency, getting the sums right.