Originally Posted by
Racing Dan
@
ofajen
Possibly. Ill have to think about it.
To my mind its the same as submarine either going 10mph (om the map) in a body of water with zero current or 0mph (on the map) with 10mph current dead against it. To do that would require the exact same power in either scenario.
I dont think 1/ is relevant. Its like calculating the power of a fence post. Nonsensical. I would however be relevant if it was a ball. What power would it take to maintain position in a 30mph "head"wind? 0w because its not moving (on the map) or the power to overcome the force of the 30 mph wind? If its 0w Im sure you could get a high paying job in an off shore operation :-)
2/ 3/ I believe you are conflating map speed with relative wind speed.
No, you are confusing the power of the head wind with the power of the cyclist. The cyclist only sees the force component of the head wind power. The power the cyclist requires to move forward against that headwind increases with the headwind force, but is still Force x Velocity of the cyclist. It's just that the Force increases with headwind.
So a stationary cyclist has to resist the headwind force to prevent being blown backward, but he doesn't produce any power at the cranks until he starts pedalling forward. He is just like a fence post. There is certainly power in the airflow, but the fence post only experiences a force derived from that power. It doesn't produce any power of its own.