The Andean giant hummingbird (Patagona gigas) has mass 70 gg and flaps its wings 10 times per second while hovering. Estimate the amount of work done by such a hummingbird in each wingbeat. g

Work = force × a. work b. energy c. distance d. momentum

Which statement is best supported by the information in the chart? wave y is moving the fastest. wave x is moving the fastest. all of the waves are moving at the same speed. all of the waves have the same value of wavelengths per second.

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.