SOLUTION: The surface area of a sphere, initially zero increase uniformly at the rate of 26 sq. cm per second. Find the rate at which the radius is increasing at then end of 2 seconds?

Algebra ->  Surface-area -> SOLUTION: The surface area of a sphere, initially zero increase uniformly at the rate of 26 sq. cm per second. Find the rate at which the radius is increasing at then end of 2 seconds?       Log On


   

Question 1082939: The surface area of a sphere, initially zero increase uniformly at the rate of 26 sq. cm per second. Find the rate at which the radius is increasing at then end of 2 seconds?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The surface area of a sphere, initially zero increase uniformly at the rate of 26 sq. cm per second. Find the rate at which the radius is increasing at then end of 2 seconds?
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"initially zero" is not relevant.
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SA = 4pi*r^2
Differentiate wrt t.
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dSA/dt = 8pi*r((dr/dt)
8pi*dr/dt = 26
dr/dt = 13/(4pi) cm/sec at 2 seconds.
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Not clear what "the end of 2 seconds" means.