Answer:0.0704 kg
Explanation:
Given
initial Absolute pressure
=210+101.325=311.325



as the volume remains constant therefore



therefore Gauge pressure is 337.44-101.325=236.117 KPa
Initial mass 

Final mass 

Therefore
=0.91-0.839=0.0704 kg of air needs to be removed to get initial pressure back

<u>Given :</u>








<u>Let's Slove :</u><u> </u>



<span>65W * 8h * 3600s/h = 1.9e6 J = 447 Cal </span>