(a) How rapidly is the area enclosed by the ripple increasing when the radius is 5 feet?

(b) How rapidly is the area enclosed by the ripple increasing at the end of 9.6 seconds?

(a) How rapidly is the area enclosed by the ripple increasing when the radius is 5 feet?

(b) How rapidly is the area enclosed by the ripple increasing at the end of 9.6 seconds?