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