A cement truck pours cement into a container in the shape of a cylinder with a radius of 4 feet. The height, h, of the cement in the container increases at a rate of approximately 10 inches per minute. Write an equation that models the volume, V, of the cement in the container in terms of h, then use the equation to determine the time at which the volume is 80π cubic feet. Note that the volume of a cylinder is V=πr2h, where r and h are the radius and height of the cylinder.