[2081 ‘B/C’] One end of a light spring having spring constant 18 N/m is attached to a rigid support. A mass of 0.15 kg is suspended from other end of the spring. A student pulls down it such that extension of spring increases by 4 cm. The student now releases it, as a result, the mass performs SHM. i. Define simple harmonic motion. ii. Calculate the maximum acceleration and time period of SHM.