A horizontal platform executes up and down S.H.M. about a mean position. Its period is `2pi` s. A mass m is resting on the platform, what is the greatest value of amplitude so that the mass 'm' may not leave the platform ?

Options

A. 4.9 m
B. 9.8 m
C. 2.25 m
D. 19.6 m

Answer

B

Explanation

For mass not to leave the platform, the maximum acceleration `a_("max")=g`.
`:." "omega^(2)r=g`
`(4pi^(2))/(T^(2)).r=g`
`r=g xx(T^(2))/(4pi^(2))`
Since `T=2pi s`.
`:." "r=gxx(4pi^(2))/(4pi^(2))=9.8" m"`
Hence correct choice is (b).