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.+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

sleep paralysis is a parasomnia, events associated with sleep.

sleep paralysis happens when you are in the middle of waking up or falling asleep. it is the feeling of being conscious but unable to move. it definitely involves hallucinations.

i had a friend that had sleep paralysis and he told me a story one time where he was laying in bed and he couldn't move his body no matter how hard he tried and there was someone standing in the corner of his room coming towards him. he couldn't move and you can't "wake up" because you are already conscious. sometimes sleep paralysis can be triggered by frequent waking up during the night based off of multiple trips to the bathroom, or if you had ever been abused, sleep paralysis can start happening from things like that.