Considering a linear function for the radius, we have that:
A linear function is modeled by:
[tex]y = mx + b[/tex]
In which:
The volume of a sphere of radius r is given by:
[tex]V = \frac{4\pi r^3}{3}[/tex]
In this problem, radius r increases at the rate of 0.03 inches per second and that r=48, hence it is represented by the following linear function:
[tex]r(t) = 0.03t + 48[/tex]
Thus, the volume of the sphere is given by:
[tex]V = \frac{4\pi r(t)^3}{3}[/tex]
[tex]V(t) = \frac{4\pi(0.03t + 48)^3}{3}[/tex]
After 300 seconds, the volume in cubic inches is given by:
[tex]V(300) = \frac{4\pi(0.03(300) + 48)^3}{3} = 775735[/tex]
More can be learned about linear functions at https://brainly.com/question/24808124