A 160.0 km long electric power line made out of copper is installed during the Spring months at an average temperature of 10.2 °C.

1) What is the change in the length of the power line on a hot summer day, when the temperature is 32.1 °C? The coefficient of linear expansion for copper is 1.62*10^ (-5) 1/C°. Use a positive sign for an increase in length and negative for a decrease.

2) What is the change in the length of the cable on a - 28.7 °C cold Winter day?

Question

Physics

Eric Glenn

21 July, 14:13

A 160.0 km long electric power line made out of copper is installed during the Spring months at an average temperature of 10.2 °C.

1) What is the change in the length of the power line on a hot summer day, when the temperature is 32.1 °C? The coefficient of linear expansion for copper is 1.62*10^ (-5) 1/C°. Use a positive sign for an increase in length and negative for a decrease.

2) What is the change in the length of the cable on a - 28.7 °C cold Winter day?

+1

Answers (1)

Know the Answer?

Ruffles · Answer 1

1.+160.0567km

2.-0.102km

Explanation:

Given initial length L1=160Km

L2=?

Initial temperature=10.2°C

Final temperature=32.1°c

Coefficient of linear expansivity a = 1.62*10^-5per Celsius

1: a=L2-L1/L1*∆T

(L2-160/160*21.9) = 1.62*10^-5

L2-160=0.0567

L2 = 0.0567+160

L2=160.0567Km

2.∆L=? at - 28.7°C

Also a=∆L/L1∆T

We're ∆L = aL1∆T

1.65*10^-5*160 * (-28.7-10.2)

=-0.102km