Rework Example 4.2, now assuming that the house has 14 windows, each measuring 45 inches high by 32 inches wide. When you buy the house, they’re single- pane windows, but when you upgrade the insulation, you also upgrade the windows to the best you can buy (see Table 4.2). Remember that the windows replace some of the wall area. Neglect any solar gain through the windows, which would increase your savings even more

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.