SOLUTION: Please help me solve this problem: A pebble is dropped into a still pool, causing ripples in the form of concentric circles. The radius r of the outer circle is increasing at a

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Please help me solve this problem: A pebble is dropped into a still pool, causing ripples in the form of concentric circles. The radius r of the outer circle is increasing at a       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1006602: Please help me solve this problem:
A pebble is dropped into a still pool, causing ripples in the form of concentric circles. The radius r of the outer circle is increasing at a rate of 25cm/s. When the radius is 100cm, at what rate is the total area of the disturbed water increasing?

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
A=pi%2Ar%5E2
A for area is a function of time t, and so it r for radius.

dA%2Fdt=pi%2A2r%2A%28dr%2Fdt%29, and Chain Rule is used.

Description gives system%28dr%2Fdt=25%2Cr=100%2CdA%2Fdt=FindThisValue%29.

highlight%28dA%2Fdt=pi%2A2%2A100%2A25%29


500%2Api