Question

A cylindrical road roller made of iron is $1m$ long. Its inner diameter is $54cm$ and thickness of the iron sheet rolled into the road roller is $9cm$. Find the weight of the roller if $1{cm}^3$ of iron weighs $8g.$

• A. $45g$
• B. $24g$
• C. $36g$
• D. None of the above

Answer 1

The correct option is D None of the above

Given, inner diameter of road roller $=54cm$ and its thickness is $9cm.$
So, internal radius $\left(r\right)=27cm$ and outer radius $\left(R\right)=27cm+9cm=36cm$
Length or height of the roller $=1m=100cm$
So, volume of the cylinder $=\pi (R^2-r^2)h=\frac{22}{7}\times ({36}^2-{27}^2)100=178200c{m}^3$
Now, it is given that $1c{m}^3$ of iron weighs $8g.$
Therefore, weight of the pipe $=178200\times 8g=1425600g=1425.6kg$