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If R is the radius of the earth and the acceleration due to gravity on the surface of earth is g = π 2 m/s 2 , then the length of the second’s pendulum at a height h = 2R from the surface of earth will be :

1. 4 m 9
2. 8 m 9
3. 1 m 9
4. 2 m 9

Correct answer: 1 m 9

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