Since the mass completes 20 cycles of oscillation in 80 s, the period of oscillation is
P = 80 s 20 = 4 s. (ii) the angular frequency of the oscillations is then 1 w 2p P 1.571 rad s . − = = (iii)
Denoting the mass by m, the spring constant is 2 1 k mw 1.234 N m . − = =
(b) For amplitude A = 2 mm = 0.002 m, the displacement, velocity and acceleration are