A woman rides on a Ferris wheel of radius 16 \rm m that maintains the same speed throughout its motion. To better understand physics, she takes along a digital bathroom scale (with memory) and sits on it. When she gets off the ride, she uploads the scale readings to a computer and creates a graph of scale reading versus time. Note that the graph has a minimum value of 510 \rm N and a maximum value of 666 \rm N . What is her mass in kilograms?