16. Which of these provides most of the oxygen in Earth's atmosphere?

coral reefs
rainforest plants
ocean phytoplankton
continental grasslands

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Eddy whose mass is 55kg climbs up the 1.50 meter high stairs in 2s.calculate eddy’s power rating

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.