Answer:
0.19 m (19 cm)
Step-by-step explanation:
The maximum speed in a simple harmonic motion is given by
(1)
where
A is the amplitude
is the angular frequency, which is given by
(2)
where T is the period.
By combining (1) and (2), we find

Here we know that
v = 60.0 cm/s = 0.6 m/s is the maximum speed
T = 2.00 s is the period
Substituting into the formula, we find the amplitude:
