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?

1 Answer
Jun 18, 2018

#"Density" = 2.6*10^3 (kg)/m^2#


Density #= "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*r^2#.

Therefore the volume of this wire is

#"volume" = L*pi*r^2 = 0.5 m*pi*(0.0025 m)^2 = 9.8*10^-6 m^2#

And the density is

#"Density" = "mass"/"volume" = (0.025 kg)/(9.8*10^-6 m^2) = 2.6*10^3 (kg)/m^2#

I hope this helps,