You accidentally leave the refrigerator door in your home open. After the refrigerator runs for an hour with the door open, is the average temperature in your home higher or lower than it was before?
- negligible thermal energy passes in or out of the outer boundary of your home (i.e. your home is perfectly insulated)
- the "average temperature in your home" is the average temperature of any and all matter within the outer boundary of your home
- the refrigerator uses electricity to lower the temperature of the air inside the refrigerator below that of the surrounding air by some unspecified means.
- the air in the refrigerator starts out at a lower temperature than the rest of your home