Answer:
a.0.120mm
b.1.58s
c.0.6329Hz
Step-by-step explanation:
a. Given that 0.120mm is displaced from equilibrium, 0.120mm after 0.790s on opposite side:
-The amplitude is the maximum displacement from equilibrium.
-The object goes from x=+A to x=-A and back during one cycle.
#Hence, the amplitude of the motion is 0.120mm
b.Motion from maximum positive displacement to maximum negative displacement takes places during half the period of Simple Harmonic Motion(SHM)

#Hence, the period of the motion is 1.58s
c. Frequency is calculated as one divided by the period of the motion.
From b above we know that the motions period is 1.58s
Therefore:
Frequency=1/period=1/1.58=0.6329Hz
#The frequency of the motion is 0.6329Hz