Question

A spring mass system is hanging from the ceiling of an elevator in equilibrium. The elevator suddenly starts accelerating upwards with acceleration a.

(a) the frequency and 

(b) the amplitude of the resulting SHM.

Answer 1

(a) Frequency = 2pi√(m/k) (Frequency is independent of g in spring)

(b) Extension in spring in equilibrium

Extension in spring in equilibrium in accelerating lift = m(g + a)/k