Waterslides are nearly frictionless, hence can provide bored students with high-speed thrills (see the figure). One such slide, Der Stuka, named for the terrifying German dive bombers of World War II, is 72.0 feet high (21.9 m), found at Six Flags in Dallas, Texas, and at Wet'n Wild in Orlando, Florida.
(a) Determine the speed of a 52.0-kg woman at the bottom of such a slide, assuming no friction is present.
(b) If the woman is clocked at 16.1 m/s at the bottom of the slide, find the work done on the woman by friction.