Question

A thin wire has a length of $21.7cm$ and radius $0.46mm.$ Calculate the volume of the wire correct to two decimal places.

Answer 1

Step 1: Given data

Length,$\left(l\right)=21.7cm,$

Radius, $\left(r\right)=0.46mm$

Step 2: Formula used

$Volumeofcylinder=\pi r^{2}l$
Where, $\pi =\frac{22}{7}$, $r$is radius, and $l$ is length.
Step 3: Finding the volume of wire

We know that,$1cm=10mm$

So, $1mm=\frac{1}{10}cm$

Now, radius,$\left(r\right)=0.46mm=0.46\times \frac{1}{10}cm=0.046cm$

The volume of wire,$V=\pi r^{2}l$ [ Wire is in the shape of a cylinder ]
$=\frac{22}{7}\times {(0.046)}^2\times 21.7$​

$=\frac{22}{7}\times 0.002\times 21.7$

$=\frac{0.9548}{7}$

$=0.136c{m}^3$

$=0.14c{m}^3$

Hence, the volume of the wire correct to decimal places is$0.14c{m}^3$.