Question

An iron beam is 9 m long. 40 cm wide and 20 cm high. If 1 cubic metre of iron weighs 50 kg. what is the weight of the beam?

(a) 56 kg

(b) 48 kg

(c) 36 kg

(d) 27 kg

Answer 1

Length of beam (l)=9 m

Breadth (b)=40 cm $=\frac{40}{100}m=\frac{2}{5}m$

and height (h)=20 cm $=\frac{20}{100}=\frac{1}{5}m$

$\therefore$ Volume $=lbh=9\times \frac{2}{5}\times \frac{1}{5}=\frac{18}{25}{m}^3$

Weight of 1 cubic m =50 kg

Total weight of beam $=\frac{18}{25}\times 50$

=36 kg