Answer:
Child A.
Step-by-step explanation:
- For all points on the merry-go-round, the angular speed ω is the same, as it's the rate of change of the angle rotated regarding time, and all points along the same radius rotate at the same time.
- Based on the definition of angular velocity, and the definition of angle, we find that there exists a fixed relationship between the angular speed and the tangential speed, as follows:

- So, since ω remains constant, the tangential speed is directly proportional to the distance from the axis of rotation r.
- This means that it will be larger for the child A, who is at a greater distance from the axis of rotation than child B.