Question

Q.8. A thin wire has a length of 21.7 cm and radius 0.46 mm. Calculate the volume of the wire to correct sig figs.

Answer 1

Given conditions ⇒

Length of the wire = 21.7 cm 
Radius of the Wire = 0.46 mm.
= 0.046 cm.

Area of the cross section = πr²
= 22/7 × (0.046)²
= 0.0066 cm². 

∴ Volume of the wire = 0.0066 × 21.7
   = 0.1443112 cm³
   =  0.14 cm³ [since, the least numbers of the significant figures is 2.]


Hence, the volume of the wire is 0.14 cm³.


Hope it helps.

Answer 2

Answer: The volume of the wire is $V = 144.2 mm^{3}$.

Explanation:

Given that,

Radius r = 0.46 mm

Length l = 21.7 cm = 217 mm

We know that,

The volume of the wire is

$V = A\times l$

$V = \pi r^{2}\times l$

$V = 3.14\times (0.46)^{2}\times 217$

$V = 144.2 mm^{3}$

Hence, the volume of the wire is $V = 144.2 mm^{3}$