Radius of a wire is 2.5mm and its lenfth is 50.0cm.If it's Mass is measured to be 25gm then find its densite up to correct significant figures?

Jun 18, 2018

$\text{Density} = 2.6 \cdot {10}^{3} \frac{k g}{m} ^ 2$

Explanation:

Density $= \text{mass"/"volume}$.

The volume of a solid cylinder is its length*the area of its cross-section. The cross-section of the wire is a circle, so the area of the cross-section $= \pi \cdot {r}^{2}$.

Therefore the volume of this wire is

$\text{volume} = L \cdot \pi \cdot {r}^{2} = 0.5 m \cdot \pi \cdot {\left(0.0025 m\right)}^{2} = 9.8 \cdot {10}^{-} 6 {m}^{2}$

And the density is

$\text{Density" = "mass"/"volume} = \frac{0.025 k g}{9.8 \cdot {10}^{-} 6 {m}^{2}} = 2.6 \cdot {10}^{3} \frac{k g}{m} ^ 2$

I hope this helps,
Steve