A beam 9 m long, 40 cm wide and 20 cm high is made up of iron which weighs 50 kg per cubic metre. The weight of the beam is

Given: Length = 9 cm


Breadth = 40 cm


Height = 20 cm


Volume of a cuboid = Length × Breadth × Height


1 m =100 cm


40 cm= 0.4 m and 20 cm =0.2 m


Volume = 9 m × 0.4m × 0.2m = 0.72 m3


Given that 1 cm3 weighs 50 kg


0.72 m3 weighs 50 × 0.72 kg = 36 kg

4