A seconds pendulum gives correct reading on the earth's surface, but when it is taken inside a mine, it goes slow by 10 s in a day. What is the depth of the mine? (Radius of the earth = 6400 km)

A seconds pendulum gives correct reading on the earth's surface, but w

1.	A seconds pendulum gives correct reading on the earth's surface, but when it is taken inside a mine, it goes slow by 10 s in a day. What is the depth of the mine? (Radius of the earth = 6400 km)
Answer» ANSWER :1481 m (APPROX.)