Hydraulic radius is caused by pressurized hydrogen air so that should mean the answer is hydraulic radius
Answer:
The circulation around the cylinder is 0.163 
Explanation:
Given :
Velocity of spinning cylinder

Sea level density

Sea level span

Lift per unit circulation is given by,

Where
circulation around cylinder



Therefore, the circulation around the cylinder is 0.163 
Answer:
"Biofuels"
Explanation:
I don't know if this counts but I guess it's not one of those.
B is the answer I believe so