A second's pendulum is placed in a space laboratory orbiting round the earth at a height of 3R, where R is the radius of earth. The time period of the pendulum is :

Options

A. zero
B. `(3)/(2)s`
C. 4 s
D. infinite.

Answer

D

Explanation

In space ship the whole of gravity is used in providing necessary centripetal force.
`:.` apparent acceleration due to gravity is zero.
Hence `T=2pi sqrt((l)/(g))` becomes infinite.
Thus correct choice is (d).