Q25. - Geometry

Question

A brick with dimensions 20 cm, 10 cm and 5 cm, weighs 1.2 kg. A second brick of the same material has dimensions 25 cm, 15 cm and 4 cm. What is its weight?

Step-by-Step Solution

Answer

The weight is$1.8\text{\hspace{0.17em}\hspace{0.17em}kg}$ .

Step 1. Given information.

Dimensions of brick are 20 cm, 10 cm and 5 am and weighs 1.2 kg.

Dimensions of second brick are 25 cm, 15 cm and 4 cm.

Step 2. Determine the weight.

Firstly, find the volume of the first brick,

$\begin{array}{c}{v}_1=20\times 10\times 5\\ =1000\end{array}$

For the $1{\text{\hspace{0.17em}\hspace{0.17em}cm}}^3$, weight of material

$\begin{array}{c}1000{\text{cm}}^3=1.2\text{kg}\\ 1{\text{cm}}^3=0.0012\text{kg [divide]}\end{array}$

 

Now, find the volume of another brick.

$\begin{array}{c}{v}_2=25\times 15\times 4\\ =1500\end{array}$

Then, the weight of the brick is

$1500\times 0.0012\text{\hspace{0.17em}\hspace{0.17em}kg}=1.8\text{\hspace{0.17em}\hspace{0.17em}kg}$