Dr. Goddyx is blowing a spherical soap bubble. He is blowing at a rate of 8 cm3/s. Notation and formulas: Let r = r(t), S = S(t), and V = V (t) be the radius, surface area and volume of the bubble at time t. You may use the following formulas for S and V . S = 4r2 , V = 4 3 r 3

1. At the instant that bubble has a radius of 10cm, how fast is the radius of the bubble increasing (in cm/sec)?

2. At the instant that bubble has a radius of 10cm, how fast is the surface area of the bubble increasing (in cm2 /sec)?