A human-powered aircraft has a gross weight of 240 lbf including the pilot. Its wing has a lift coefficient of 1.5 and a lift- to-drag ratio of 70. Estimate the wing area needed and the pilot power that must be provided for this craft to cruise at 15 mph. Assume that the wing profile drag is about 40 percent of the total drag and the propeller efficiency is 80 percent.

Which of the following is an easy way to remember the modified “x” tire rotation? a. nondrive wheels straight, cross the drive wheels b. drive wheels straight, cross the nondrive wheels c. drive wheels crossed, nondrive wheels straight d. drive wheels crossed, nondrive wheels crossed

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented