It is widely agreed that such an object -- 10 kilometers across ... greater than average in the Cretaceous/Tertiary (KT) boundary, the layer of sedimentary rock laid down at the time of the ...

boundary. This geological signature consists of a thin layer of sediment found across the planet in both marine and terrestrial rocks; it is often identified by the sharp, almost dramatic ...

This friction is associated with the development of boundary layers, and it scales with Reynolds number as we have seen above. Pressure drag comes from the eddying motions that are set up in the fluid ...