Sally enjoyed the chance to gather data from standing waves in a spring. She and her partner held the ends of the spring 4.0 meters to one side. There were 5 nodes in the standing wave generated. Sally moved her hand from the rest position back and forth all along the floor 20 times in 4 seconds. Determine the frequency of the wave Sally created?
i) 10/second
ii) 5 hz
iii) 10 hz
iv) 1 hz