A boy with a mass of 41 kg rides a merry-go-round at 2.0 m/s, requiring a force of 79 N to stay on. The discussion focuses on determining the radius of the merry-go-round using the formula F=mv^2/r. Participants clarify that the type of acceleration involved is centripetal and confirm the correct application of the formula. The unknown quantity in the equation is the radius, with one participant suggesting a possible value of 0.481. The conversation also touches on centripetal acceleration calculations for an airplane flying in a circle.