[填空题]
In Problem 59, the length o/ d:.)u1srye/w qcw wb4 l.icff the string may be a gz2r765dvs rkdjusted by moving the pulley. If the hanging mass m is fixed at 0.080 kgs vz6rg5k7d2r , how many different standing wave patterns may be achieved by varying L between 10 cm and 1.5 m?