Saturday, May 5, 2012 6:05:44 PM
"How can he be going that fast on a bike? Somebody please explain this."
For objects travelling in a fluid at low velocities characterised by a low Reynolds number (Re<1), drag force is roughly proportional to velocity. As velocity increases, so does drag force (Fd), until further acceleration due to propulsion force (Fp) is no longer possible as Fd approaches Fp. Drafting in the burble behind a large moving truck reduces the effective Fd so that the equilibrium point Fd=Fp occurrs at a higher velocity.