Practice Problem 1-2

Practice Problem 1-2

Given: A stack of 144 (a "gross" is 144) 8.0-foot long fir 4 x 4s is required for fenceposts.

Req'd: The total weight of the stack.
Hint: lumber is "dressed" or milled down generally a half-inch under its nominal dimensions. 4 x 4 lumber has net dimensions of 3.5 x 3.5 inches. The weight density of the wood is 32.5 lb/ft³.

Solution: The ends of the "4x4s" have lengths of 3.5" = 0.292 ft. The volume of a post is then:

V = (0.292 ft)²*8 ft = 0.681 ft³

The weight of a post is W = Volume x Density = 0.681 ft³ * 32.5 lb/ft³ = 22.1 lb

The weight of all 144 posts is then 144 * 22.1 lb = 3190 lb.

Updated: 07/31/2006