Question

In a certain time interval, natural gas with energy content 15000 J was piped into a house during a winter day. In the same time interval sunshine coming through the windows delivered 2000 J of energy into the house. The temperature of the house didn’t change. What was ∆Ethermal of the house?

Answer 1

`\Delta E_(thermal) = 17000\,J`

Step-by-step explanation:

Since the temperature of the house does not change, the net heat transfer rate must be zero by the First Law of Thermodynamics. It means that heat input must be equal to the heat output from the house. Then:

`\Delta E_(thermal) = Q_(gas) + Q_(rad)`

`\Delta E_(thermal) = 15000\,J + 2000\,J`

`\Delta E_(thermal) = 17000\,J`