SOLUTION: A stone is thrown into a lake and a circular ripple moves out at a constant speed of 1m/s. Find the rate of change of the circle’s area at the moment when t= 4s.

Algebra.Com
Question 1106185: A stone is thrown into a lake and a circular ripple moves out at a constant speed of 1m/s. Find the rate of change of the circle’s area at the moment when t= 4s.
Answer by ikleyn(52855)   (Show Source): You can put this solution on YOUR website!
.
You are given for the radius R(t) = t, where "t" is time in seconds.


The area of the circle is A(t) =  = .


The rate of change of the circle’s area is   = .


At t = 4 seconds,   =  =  = 25.12 m^2/s.

Solved.


RELATED QUESTIONS

A stone dropped into a still pond sends out a circular ripple whose radius increases at a (answered by rothauserc)
A stone is tossed into a pond creating a circular ripple. The radius of the ripple... (answered by greenestamps)
A stone is thrown into a pond. A circular ripple is spreading over the pond in such a way (answered by ankor@dixie-net.com)
A ball is thrown into a lake, creating a circular ripple whose radius travels outward at... (answered by ikleyn)
A circular ripple spreads across a lake. If the area of the ripple increases at a rate... (answered by Edwin McCravy,ikleyn)
A raindrop falls into a puddle and causes a circular ripple to (answered by terbear1963,stanbon)
. Tobey sits by the lake and throws a stone into it. The path of the stone is described... (answered by ikleyn)
Ushna sits by the lake and throws a stone by it. The path of the stone is described by... (answered by ewatrrr)
A toy train measures 1/4 m long. How long will it take for the train to pass a 1m long... (answered by ikleyn)