Chapter 5, Problem 15P

* 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

$d\text{. }{\left(\frac{2\pi N}{20s}\right)}^2$

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

$d\text{. }{\left(\frac{2\pi N}{20s}\right)}^2$

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 $d\text{. }{\left(\frac{20}{2\pi t}\right)}^2$.