A rotating merry-go-round makes one complete revolution in 4.0 s (Fig. 8–41).

VIDEO TRANSCRIPT

This is Giancoli Answers with Mr. Dychko. To answer parts (a) and (b), you'll need to know what the angular velocity is so let's figure out that first. The merry-go-round does one complete circle of 2π radians in every 4 seconds so divide 2π by 4 and you get 1.5708 radians per second is the angular velocity. So the linear velocity of a point 1.2 meters away from the center of the merry-go-round is gonna be r times angular velocity. That's 1.2 meters times 1.5708 radians per second that gives 1.9 meters per second is the linear velocity of a point at 1.2 meters from the center. And then the acceleration, well, the tangental acceleration is zero because there's no angular acceleration, the angular velocity is constant so that means angular acceleration is zero so this tangental component to the acceleration is zero. The radial component of the acceleration is angular velocity squared times r and that's gonna be 1.5708 radians per second squared times 1.2 meters that gives 3.0 meters per second squared of radial acceleration towards the center of the merry-go-round.