Question

Harold is a woodworker and is interested in finding the density of two different types of wood. He bought a pine log that has a 5-inch radius and is 30 inches long. The weight of the log is approximately 42.63 pounds. He also has an oak board that is 5.5 inches wide, 1.5 inches thick and 3 feet long. The board weighs approximately 8.05 pounds.

Answer 1

Equation for Density = Mass / Volume

Solving for density of log:
radius = 5 inches
Area of a circle = pi(radius)^2 = (3.1415)(25 inches squared) = 78.53 inches squared
volume = area * length = (78.53 inches sqrd)(30 inches) = 2,356.125 cubic inches
log density = 42.63 lbs / (2,356.125 inches sqrd) = 0.018 lbs/ cubic inch

Solving for density of Oak Board:
volume = (5.5 inch)(1.5 inch)(36 inch) = 297 cubic inches
board density = 8.05 lbs / 297 cubic inches = 0.027 lbs/cubic inch

Answer 2

Answer: log is cylinder and the board is rectangular prism