* You want to determine the radial acceleration of a friend who is standing on the rotating platform of a merry-go-round. You have a stopwatch and a measuring tape. Which of the following procedures would best serve your task?
a. Measure the distance d between the point where the person is standing and the axis of rotation, count the number of rotations N of the platform in 20 seconds, and calculate
b. Measure the distance d between the point where the person is standing and the edge of the platform, count the number of rotations N of the platform in 20 seconds, and calculate
c. Measure the distance d between the point where the person is standing and the axis of rotation, measure the time t for 20 revolutions of the platform, and calculate
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