Question

Una barra de hierro cuya longitud inicial es de 2m se le incrementa su temperatura de 20 °C a 120 °C ¿Cuál es la longitud final de la barra? (considera que el coeficiente de dilatación del hierro) es 1,2 x 10-5 1/°C ( 3 puntos)

Answer 1

Answer:

1.9976 m

Explanation:

An iron bar whose initial length is 2m has its temperature increased from 20 ° C to 120 ° C. What is the final length of the bar? (consider that the coefficient of expansion of iron) is 1.2 x 10-5 1 / ° C (3 points)

Given that,

Initial length of an iron bar, $L_0=2\ m$

The temperature increased from 20°C to 120°C

The coefficient of expansion of iron is $1.2\times 10^{-5}\ /^{\circ} C$

We need to find the final length of the bar.

The linear expansion equation is given by :

$\Delta L=\alpha L\Delta T$

Where $\Delta L$ is the change in length

$\Delta L=1.2\times 10^{-5}\times 2\times (120-20)\\\\=0.0024\ m$

Also, $\Delta L = L_o-L$

L is final length

$0.0024= 2-L\\\\L=2-0.0024\\\\=1.9976\ m$

So, the final length of the bar is 1.9976 m