[填空题]
A fisherman’s scale stretches 3.+cx(o 1fn5 2k s0czh+tjkym;h 6 cm when a 2.7-kyh( u6qqwb6 +dg fish hangs from it. (a) What is the spring stiffness conswu+(q66qydb htant $\approx$ N/m
(b) what will be the amplitude and frequency of vibration if the fish is pulled down 2.5 cm more and released so that it vibrates up and down? $\approx$ Hz (round to one decimal place)