Respuesta :

Answer:

The length after elongation is 0.1243 m

Solution:

As per the question;

Length of the iron vat, L = 14 m

Temperature, T  = [tex]20^{\circ}[/tex] = 293 K

Temperature at 1 atm, T' = [tex]100^{\circ}[/tex] = 373 K

Pressure, P = 1 atm

Thermal expansion coefficient, [tex]\alpha = 11.1\times 10^{- 6}/^{\circ}C[/tex]

Now,

Change in length is given by:

[tex]\Delta L = \alpha L\Delta T[/tex]

[tex]L' - L = \alpha L\Delta T[/tex]

[tex]L' = L(1 + \alpha L\Delta T)[/tex]

[tex]L' = 14(1 +  11.1\times 10^{- 6}(100 - 80)[/tex]

L' = 0.1243 m

Explanation:

It is given that,

Length of iron bar, l = 14 m

Room temperature, T = 20° C

Pressure, P = 1 atm

The change in length due to change in temperature is called linear expansion. It is given by :

[tex]\Delta l=l\alpha \Delta T[/tex]

[tex]\alpha[/tex] is the coefficient of linear expansion,[tex]\alpha =12\times 10^{-6}\ C^{-1}[/tex]

We know that the boiling temperature of water T' = 100° C

[tex]\Delta l=l\alpha (T'-T)[/tex]

[tex]\Delta l=14\times 12\times 10^{-6}\times (100-20)[/tex]

[tex]\Delta l=0.0134\ m[/tex]

So, the new length of the iron rod is, [tex]L=14\ m+0.0134\ m=14.013\ m[/tex]

Hence, this is the required solution.