#### Answer

15.7 ft/sec

#### Work Step by Step

Given The diameter of a carousel (merry-go-round) is 30 ft. At
full speed, it makes a complete revolution in 6 s.
We need to find out At what rate, in feet per second, is a horse on the outer edge moving
Rate = $\frac{total distance traveled in one revolution}{time taken for one revolution}$
= $\frac{Perimeter o the circular path}{time taken to cover one revolution}$
= $\frac{2\pi r}{6}$
= $\frac{\pi d}{6}$
= $\frac{\pi * 30}{6}$
= 5$\pi$ = 15.7 ft/sec