Question #e406e

3 Answers
Jul 25, 2015

I found: mass=1xx10^-3kgmass=1×103kg

Explanation:

Considering it as a cylindrical wire you can evaluate its volume VV as:
V=pir^2xxh=3.14(0.002/2)^2xx0.32=1xx10^-6m^3V=πr2×h=3.14(0.0022)2×0.32=1×106m3
From:
denisity=(mass)/(volume)denisity=massvolume
mass=densityxxvolume=1000xx1xx10^-6=1xx10^-3kgmass=density×volume=1000×1×106=1×103kg

Jul 25, 2015

Mass of the wire: 1 g

Explanation:

Density is defined as mass per unit of volume.

In your case, the density of the wire is known to be equal to "1000 kg/m"""^31000 kg/m3, which means that "1 m"""^31 m3 of volume will have a mass of "1000 kg"1000 kg.

So, in order to determine the mass of the wire, you need to know what volume it occupies. You can assume it to have the shape of a very long and thin cylinder, so that tis volume can be determine by using

V = pi * r^2 * hV=πr2h, where

rr - the radius of the wire;
hh - its length.

In your case, the wire hs a diameter of 0.002 m, which means that its radius will be

r = d/2 = "0.002 m"/2 = "0.001 m"r=d2=0.002 m2=0.001 m

The wire's volume will thus be

V = pi * ("0.001 m")^2 * "0.32 m" = 1.0 * 10^(-6)"m"^3V=π(0.001 m)20.32 m=1.0106m3

This means that the mass of the wire will be

1.0 * 10^(-6)cancel("m"^3) * "1000 kg"/(1cancel("m"^3)) = 1.0 * 10^(-3)"kg"

Expressed in grams and rounded to one sig fig, the number of sig figs you gave for the diameter of the wire, the answer will be

1.0 * 10^(-3)cancel("kg") * (10^3"g")/(1cancel("kg")) = color(green)("1 g")

Jul 25, 2015

1 gram (CGS) or 10^-3 Kg (SI)

Explanation:

assuming the wire is cylindrical:

Area of the cross section: pi*r^2= 3.14*(0.002/2 )^2=3.14*0.000001=3.14*10^(-6) m^2

Total volume=area x length: 3.14*10^-6*0.32=1*10^-6m^3

Total mass=volume x density: 1*10^-6m^3*1000 (Kg)/(m^3)=10^-3Kg=1g

The numbers were chosen to make the math very simple. The total mass is 1 gram.

Incidentally, this wire is made of a material with the same density as water (real metals are much denser).