Specific Latent heat 1. (a) The melting point and boiling point of lead are 327 and 1774 degrees Celsius
and -219 and -183 for Oxygen.
(i) At - 200 °C will the oxygen be a solid, liquid, or gas?
(ii) At 450 °C will the lead be a solid, liquid, or gas?
(b) The graph shown alongside shows how the temperature of a pure substance
changes as it is heated.

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.