A) 1.0
B) 0.1
C) 1.1
D) 2.0
Correct Answer: B
Solution :
Let\[A=\pi {{r}^{2}}.\] \[\frac{dA}{dt}=2\pi r.\frac{dr}{dt}\] \[6\pi =2\pi (30).\frac{dr}{dt}\] \[\Rightarrow \]\[\frac{3}{30}=\frac{dr}{dt}\Rightarrow \frac{dr}{dt}=\frac{1}{10}=0.1\] Thus, the rate at which the radius of the circular sheet increases is 0.1You need to login to perform this action.
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