The rate of change of the volume of a snowball that is melting is proportional to the surface area of the snowball. Suppose the snowball is perfectly spherical. Then the volume (in centimeters cubed) of a ball of radius r centimeters is \(\displaystyle\frac{{4}}{{3}}\pi{r}^{{3}}\). The surface area is \(\displaystyle{4}\pi{r}^{{2}}\).Set up the differential equation for how r is changing. Then, suppose that at time \(t = 0\) minutes, the radius is 10 centimeters. After 5 minutes, the radius is 8 centimeters. At what time t will the snowball be completely melted.