The park is 2640 feet wide. It is (43560)(840)=36,590,400 square feet.

That means the length is 13,860 feet.

The perimeter is 2(13860)+2(2640)=33,000 feet or 6.25 miles.

Sinc eht ewalkers are heading toward one another around the park, their cumulative speed is 11 mph.

Since d=rt,

Multiply by 60 and we find it takes a little over 34 minutes.