A circular ripple in a pond is produced when a rock is dropped into the water. If the outer radius of the ripple is expanding at a rate of 24 cm/sec, at what rate is the area of the circular ripple changing when the radius is 80 cm. ?

7 years agodo we know of a relation that relates these?

7 years agoradius to area

7 years agoyou said you needed help right?

7 years agono i dnt kno the relation

7 years agoHmm, would you agree that the area of a circle is determined by the equation: pi r^2 ?

7 years agoyes and the derivative of that is pi*2r

7 years agocorrect, except for we need to include an r' for the rate of the change of the radius

7 years ago\[A = pi\ r^2\] \[A' = 2pi\ r\ r'\]

7 years agor' is told to us to be 24, and the radius = 80

7 years agoA' = 2pi * 2 * 80 then

7 years agothat 2 meant 24

7 years agomy keyboard hates me

7 years agolol i understood what you mean ... but when i did all that i qot 12063.71579

7 years agoright, cm per sec

7 years agoi had that answer but it was telling me i was wrong but i had a 5 instead of 6 thnk yu sooooo much yu r qreatly appreciated

7 years agoyoure welcome, good luck with all of it :)

7 years agothnx

7 years agoA 14 foot ladder is leaning on a wall, slowly sliding down. If the base of the ladder is sliding away from the wall at 1.3 ft/second, how fast is the top sliding vertically along the wall when the bottom of the ladder is 9 feet from the wall? do i approach it the same way ?

7 years ago