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

Answer:

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

Answer 2

First we will try to find the volume of the beam by using the formula we use in case of a cuboid.

So,the volume of the beam is= lbh

=900cm×50cm×20cm

=45000sq.cm×20cm

=900000cubic cm

=0.9cubic metres

Now,given that weight =30kg/cubic metre

Total weight of the beam=30×0.9kg

=27kg

Answer : 27kgs is the total weight of the beam.