A balloon is being filled with air at a rate of 3 cubic meters per minute. Find the rate at which the radius is changing when the volume is 113.0973355 cubic meters.

Answer 1

V = (4/3)πr^3
dV/dt = 4πr^2 dr/dt

we know dV/dt, but we have to find r

113.0973355 = (4/3)πr^3 , ( I am sure they gave you that number as 36π)
r^3 = 27
r = 3

subbing in
3 = 4π9) dr/dt
dr/dt = 1/(3π) m/min