A ball is released at a height of 16 inches to roll inside a half-cylinder. It rolls to a height of 8 inches on the other side of the cylinder on roll 1. Each time it
rolls up a side of the cylinder, the ball reaches a point that is as high as it
had reached on the other side.
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This explicit formula models the height of the ball, in inches, the nth time it
rolls up a side of the cylinder.

How high does the ball roll on its 5th time up the cylinder's side?