HELP Earth’s mantle is

a.

a layer of molten metal.

b.

a layer of hot rock.

c.

a dense ball of solid metal.

d.

a layer of rock that forms Earth’s outer skin.

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

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.

Which composition of water moves to begin a deepwater current?