If red oak lumber weighs 63 pounds per cubic foot, how much does one cord of red oak weigh? (A cord is a measurement for bulk wood-8 feet long, 4 feet wide, and 4 feet high.)

A. 8,192 pounds

B. 7,936 pounds

C. 8,064 pounds

D. 4,032 pounds

Answer: Option C. 8,064 pounds

Solution:

Unit weight: U=63 pounds/foot^3

Total Weight: W=?

W=U*V

Volume: V

Length: l=8 feet

Width: w=4 feet

Height: h=4 feet

V=l*w*h

Replacing the knwon values in the formula above:

V = (8 feet) * (4 feet) * (4 feet)

V=128 feet^3

Replacing in the formula of total Weight:

W=U*V

W = (63 pounds/foot^3) * (128 feet^3)

W=8,064 pounds