Step-by-step explanation:
Volume of a sphere is:
V = 4/3 π r³
where r is the radius (half the diameter).
The volume of each sphere is:
V = 4/3 π (4 ft / 2)³ = 32/3 π ft³ ≈ 33.510 ft³
V = 4/3 π (2 ft / 2)³ = 4/3 π ft³ ≈ 4.189 ft³
V = 4/3 π (1 ft / 2)³ = 1/6 π ft³ ≈ 0.524 ft³
V = 4/3 π (1/2 ft / 2)³ = 1/48 π ft³ ≈ 0.065 ft³
The weight of each sphere is:
W = 33.510 ft³ × (62.4 lb/ft³) = 2091.044 lb
W = 4.189 ft³ × (62.4 lb/ft³) = 261.381 lb
W = 0.524 ft³ × (62.4 lb/ft³) = 32.673 lb
W = 0.065 ft³ × (62.4 lb/ft³) = 4.084 lb
The total weight is 2389.181 lb.