Marble in a bowl

Consider a bowl in the shape of a perfect hemisphere with radius $$R = 19 \text{ cm},$$ as shown in the diagram below. Now, place a spherical marble with radius $$r = 1 \text{ cm}$$ on the edge of the bowl $$($$point $$A)$$ and let it roll.

How long does the marble take to reach the bottom of the bowl $$($$point $$B)?$$

Assume a gravity acceleration of $$g = 10 \text{ m/s}^2.$$

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