Suppose oil spills from a ruptured tanker and spreads in a circular pattern. If the radius of the oil spill increases at a constant rate of 1 m/s, how fast is the area of the spill increasing when the radius is

Question

23 m?

Answer 1

so you have
A = πr^2
dA/dt = 2πr dr/dt
Plugging in your numbers,
dA/dt = 2π(23m)(1m/s) = 46π m^2/s