A 25 ft ladder is leaning against a wall when its base starts to slide away from the wall. By the time its base is 7 ft from the wall, the base is moving at the rate of 2 ft/sec. How fast is the top of the ladder sliding down the wall then?

Which type of bond is found between the atoms of a molecule? a. metallic b. delocalized electron c. covalent d. ionic

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.

How does an observation about an object differ from an inference about that object