I drew a square with each side being 8 inches long. I then divided the square into 8 sections. Each section was 1 inch wide and 8 inches long. Then I shaded in one section of the square.
The fourth option is correct.
See the attached image. The red cylinder represents a washer formed by the described revolution. Its volume is
so when we integrate, we take
Yes the square root of 1/4 is a rational number
60 minutes. Take how far it is above ground (20 m) and add it to the absolute value of how far it is below ground (340 m) to get 360 meters, which you divide by the rate of descent (6 m/min) to get 60 minutes.
