Consider a beam of light passing through a slab of some refractive index.
We know that the speed and wavelength of the light changes, but its frequency remains the same.
Since the wavelength of the light changes, does its colour change, or does it remain the same as its frequency remains the same.
Consider this aerofoil. Let the leftmost point be S and rightmost point be E. Let the topmost point be T and a point on the bottom of the foil be B.
Let the wind blow as shown in the figure above.
Bernoulli's principle says that the air blowing along S-T-E must travel a path longer than than...