Me : )

a cup of was left in the sun for 4 hours. it started with 230j of internal energy and ended with 580j of internal energy.
a) how much heat was transferred?
b) was the heat transferred in or out of the cup?

A) 350 J

- The initial internal energy of the cup is

- The final internal energy of the cup is

According to the first law of thermodynamics:

where

Q is the heat absorbed by the system

W is the work done on the system

The work done on the system in this case is 0, so we can rewrite the equation as

And so we find the heat transferred

B) IN the cup

Explanation:

in this situation, we see that the internal energy of the cup increases. The internal energy of an object/substance is proportional to its temperature, so it is a measure of the average kinetic energy of the molecules of the object/substance. Therefore, in this case, the temperature (and the energy of the molecules of the substance) has increased: this means that heat has been transferred INTO the system from the environment (the heat came from the sun).

sleep paralysis is a parasomnia, events associated with sleep.

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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.

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