As soldiers get bigger and packs get heavier, a parachutist and load can weigh as much as 400 lbf. The standard 28-ft parachute may descend too fast for safety. For heavier loads, the U.S. Army Natick Center has developed a 28-ft, higher drag, less porous XT-11 parachute (see the URL www.natick.army.mil). This parachute has a sea-level descent speed of 16 ft/s with a 400-lbf load.
(a) What is the drag coefficient of the XT-11?
(b) How fast would the standard chute descend at sea-level with such a load?