Two spring of force constants `K` and `2K` are connected a mass `m` below The frequency of oscillation the mass is

Options

A. `(1//2pi)sqrt((K//m))`
B. `(1//2pi)sqrt((2K//m))`
C. `(1//2pi)sqrt((3K//m))`
D. `(1//2pi)sqrt((m//K))`

Answer

C

Explanation

`T=2pisqrt((m)/(K+2K))`, as `K_(eq)=K+2K`
`therefore f=(1)/(2pi)sqrt((3K)/(m))`.