Each year of its life, a tree grows a new ring just under the outside bark. The new ring consists of two parts, light-colored springwood, when the tree grows the fastest, and a darker-colored summerwood, when growth slows. When conditions are good and there is lots of sun and rain, the new ring is thicker than the rings formed when there is drought or excessive cold. At the center of the tree is a dark circle called pith that is not connected to the age of the tree. Describe the history of the tree in the diagram.

The redwood trees of coastal California are the tallest living things on earth. One redwood is 350 feet tall, 20 feet in diameter at its base, and around 2000 years old. Assume that the lower 50 feet of the tree form a cylinder 20 feet in diameter and that all of the rings grew at the same rate.
What is the total volume of wood in the 50-foot section? Use 3.14 for π.
How wide is each annual ring (springwood and summerwood combined)? Disregard the bark and pith in your calculations. Show your work. Write your answer in inches.