# The Time-keeper

A man sits on the inner side of a hollow sphere and measures the seconds as they pass. Find the time (in $$\si{\second}$$) he measures during one oscillation of the pendulum.

Details and Assumptions

• Length of string is $$l=1 \text{ m}$$
• Radius of sphere is $$R=1 \text{ m}$$
• String is attached at point $$P$$ and man sits diametrically opposite to this point.
• Masses of both man and sphere are same.
• The man doesn't slip on the sphere ie., he sits at the same point on the sphere.

• Assume the figure at the bottom of the sphere to be the man.

• The oscillations take place in uniform gravitational field where $$g = 9.81$$ SI units.

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