SOLUTION: a pebble is dropped into a calm pond causing ripples in the form of concentric circles. the radius of the outermost circle (in feet) is given by r(t)=0.6t where t is the time in se

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Question 713033: a pebble is dropped into a calm pond causing ripples in the form of concentric circles. the radius of the outermost circle (in feet) is given by r(t)=0.6t where t is the time in seconds after the pebble hits the water. the area of the circle (in square feet) is A(r)=(pi)r^2. What is the area of the circle after 5 seconds. What equations did you use to get your answer?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+t+=+5+ sec
+r%28t%29+=+.6t+
+r%285%29+=+.6%2A5+
+r%285%29+=+3+ ft
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+A%28r%29+=+pi%2Ar%5E2+
+A%283%29+=+pi%2A3%5E2+
+A%283%29+=+pi%2A9+
+A%283%29+=+28.274+ ft2