air is being pumped into spherical balloon at 5 ft.³ per minute. what Is the rate of change of the radius when the radius is 2 feet

Answer 1

Use the equation V=4πr³/3 then take the derivative to get dV/dt =4πr²dr/dt and solve for dr/dt which gives dr/dt= dV/dt(1/4πr²) and using the values given dr/dt= 5/16π ft/sec