Question

A beam 9 metre long ,50 cm wide, and 20 cm deep is made of wood which weighs 30 kg per metre cube, find the weight of the beam.

Answer 1

Length of beam(l)=9 m
Breadth of beam(b)=50 cm
=0.5 m
Depth of beam(h)=20 cm
=0.2 m
Volume of beam=lbh
= 9×0.5×0.2 m³
=0.9 m³
Given,
weight per cubic metre=30 Kg
weight for 0.9 m³=0.9×30
=27 Kg