Step-by-step explanation:
Given that,
Mass of the block, m = 300 g = 0.3 kg
Linear spring constant, k = 6.5 N/m
(a) Let T is the period of the block's motion. It is given by :

where
= angular frequency
Also,



T = 1.34 seconds
(b) The maximum acceleration of the block is,

The maximum acceleration is given by :

A is the amplitude of the motion,




A = 0.09 meters
Hence, this is the required solution.