Given data
*The given mass of the child is m = 65 kg
*The given number of revolutions is 12.0
*The given time is t = 35.2 s
*The given radius of the barrel is r = 3.50 m
The frequency is calculated as
The formula for the linear velocity is given as
Substitute the known values in the above expression as
The formula for the centripetal force is given as
Substitute the known values in the above expression as
The formula for the centripetal acceleration is given as
Substitute the known values in the above expression as