Suppose a rock dropped into a pond creating a circular ripple travelling at a speed of 80 cm/s In an outward direction. ()a) Let r be the radius of...

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Suppose a rock dropped into a pond creating a circular ripple travelling at a speed of80 cm/s In an outward direction.()a) Let r be the radius of the circle. Express r as a function of time, t, in seconds.bj If A is the area of this circle as a function of the radius, find Mer and interpret it.