Question

A person starts a 60 w table fan in an insulated room of volume 86.4 ????3. the person expects to cool the room from 320???? (pressure = 100 kpa) and allows the fan to rotate for 4 hrs. after 4 hours, the person will find that the room is (???????? = 0.718 ????????/???????? − ????, ???? = 0.287 ????????/???????? − ????)

Answer 1

First calculate work done by the motor=60×4×3600=864000J

Then get the mass from PV=mRT

The mCv∆T=864Kj put all the values you will get the answer ...approx 12°C increases....the reason is that the room is insulated