A vertical helical spring having a stiffness of 1540 N/m is clamped at its upper end and carries a mass of 20 kg attached to the lower end. The mass

A vertical helical spring having a stiffness of 1540 N/m is clamped at its upper end and carries a mass of 20 kg attached to the lower end. The mass is displaced vertically through a distance of 120 mm and released. Find :
1. Frequency of oscillation ;
2. Maximum velocity reached ;
3. Maximum acceleration;and
4. Maximum value of the inertia force on the mass