The periodic time of a particle performing a linear S.H.M. is 12 sec. It starts from the mean position. After 2 seconds, its velocity is found to be `pi cm//sec`. What is the amplitude of S.H.M. ?

Options

A. 4cm
B. 8cm
C. 12 cm
D. 16cm

Answer

C

Explanation

`v =A omega "cos" omega t`
`therefore pi =A . (2pi)/(12)xx "cos" (2pi)/(12)xx2`
`therefore pi=A(pi)/(6)xx "cos" (pi)/(3)=(piA)/(6)xx(1)/(2)`
`therefore 1=(A)/(12) therefore A=12 cm`