A steel reinforcing rod is 12 ft. long and 1" thick in diameter. If a cubic foot of steel weighs 490 lb., how much does the rod weigh (to the nearest pound)?
In cubic feet, the volume of the rod is given by the formula for the volume of a cylinder. .. V = (π/4)*d^2*h .. = (π/4)*(1/12 ft)^2*(12 ft) .. = π/48 ft^3
Then the weight is .. (490 lb/ft^3)*(π/48 ft^3) ≈ 32 lb
