Toby has two vertical hanging springs, one on his left "L" and the other on his right "R". He hangs his left shoe on spring L and gets it oscillating. He hangs his right shoe on spring R and gets it oscillating also. The two shoes have equal mass, and during the oscillations, the two shoes have equal maximum speed. However, the left shoe oscillating on spring L has twice the amplitude as the right shoe does on spring R. If spring L has constant k = 174 N/m, how much is the spring constant for spring R?