Which of the following can be observed without changing the chemical makeup of a substance? a. rusting b. burning c. any chemical property d. any physical property

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.

In the first law of thermodynamics, triangle e=q-w, what does q stand for

What is a possible result of higher air temperature caused by global warming