Question

3. A student living in a 4-m X 6-m X 6-m dormitory room turns on her 150-W fan before she leaves the room on a summer day, hoping that the room will be cooler when she comes back in the evening. Assuming all the doors and win- dows are tightly closed and disregarding any heat trans- fer through the walls and the windows, determine the tem- perature in the room when she comes back 10 h later. Use specific heat values at room temperature, and assume the room to be at 100 kPa and 15°C in the morning when she leaves. Answer 58.2 C il ROOM 4mx6m×6m Fan

Answer 1

Accerding to the Censerovetono Eresa e con uon e Cendemvab'on ay Can wrmbe Nouw Work done Elechic fan is nothung but enal to the Chngeinntesnal Enarsy rom Ideal Ge Gas Castant 3o p v → 15+273 2 100KPa (4x6x6)rn → 100KPa. K 0.2.97 K Pa m k3 m.2 174.216 Kg x 288 Elechic werk by fan is 5400 KJ

Now Tad 58.1602/ CAns) 58.2°C ,