APFIVE Rate of Change of a Circle's Area
If the radius of a circle increases linearly with time as shown above, what is the rate of change of the circle’s area at $$t = 4\,s$$?
| t (s) | r (cm) |
|---|---|
| 0 | 3 |
| 2 | 4 |
| 4 | 5 |
A
$$2.5\pi \;cm^2/s$$
B
$$\pi \;cm^2/s$$
C
$$5\pi \;cm^2/s$$
D
$$10\pi \;cm^2/s$$
Question Leaderboard
Not enough data yet to show leaderboard.