A pendulum clock is taken `1km` inside the earth from mean sea level. Then the pendulum clock

Options

A. loses 13.5 s per day
B. gains 13.5 s per day
C. loses 7 s per day
D. gains 7 s per day

Answer

C

Explanation

`(Delta T)/(T) =-(1)/(2) (Delta g)/(g)=(-(1)/(2))(-(d)/(R))=(d)/(2R)`
`Delta T = (1 km)/(2(6400 km)) (86400s) = 6.75` s per day loses