Question

The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (gmoon =gearth/6) is

(a) ωn

(b) 0.408ωn

(c) 0.204ωn

(d) 0.167ωn

I have been asked this question at a job interview.

My doubt is from Bifilar and Trifilar Suspension topic in section Simple Harmonic Motion of Machine Kinematics

Answer 1

The correct choice is (a) ωn

The explanation: We know natural frequency of a spring mass system is,

ωn = √k/m ………………….(i)

This equation (i) does not depend on the g and weight (W = mg)

So, the natural frequency of a spring mass system is unchanged on the moon.

Hence, it will remain ωn , i.e. ωmoon =ωn.