Answer:
Option c)
10π ft^2/ft
Explanation:
Area of the circular puddle = A
=[tex]\pi r^2[/tex]
Where r is the radius of the circular puddle
Since the area of the circular puddle is constantly changing with respect to radius
Therefore, the differential equation hence formed will be
= [tex]\frac{d(A)}{dr}[/tex]
On putting the value of A
= [tex]\frac{d(\pi r2)}{dr}[/tex]
On differentiating
= 2πr
Hence , Area= A= 2πr
Putting the value of r = 5ft
Area = [tex]2\times 5\pi ft[/tex]
= [tex]10\pi ft^2/ft[/tex]
