Apentix/AP Calculus AB/Unit 4: Contextual Applications of Differentiation/Question
AP Calculus ABhardmcq1 pt

A pebble is dropped into a still pond, creating a circular ripple. The radius of the ripple is increasing at a constant rate of $2$ feet per second. Which of the following correctly relates the rate of change of the area $A$ enclosed by the ripple to its radius $r$?

Explanation

Core Concept

Correct. The area of a circle is $A = \pi r^2$. Differentiating both sides with respect to time $t$ yields $\frac{dA}{dt} = 2\pi r \frac{dr}{dt}$.

Correct Answer

q5_a

Practice more AP Calculus AB questions with AI-powered explanations

Start Practicing on Apentix →
    A pebble is dropped into a still pond, creating a circular r... | AP Calculus AB | Apentix