A drop of oil of volume 10^-10 spreads out on water to make a circular film of radius 10-¹m.What is the thickness of the film?
since v = πr^2 h, we have
π(1/10)^2 h = 10^-10
h = 10^-10/(π/100) = 10^-8/π
π(1/10)^2 h = 10^-10
h = 10^-10/(π/100) = 10^-8/π