The area of a glass window is 1.2 m^(2). The thickness of the glass is 2.2 mm. If the temperature outside is 36°C and the temperature inside is 26°, calculate the heat flowing into the room every hour. Thermal conductivity of glass is 0.8 Wm^(-1) K^(-1).

The area of a glass window is 1.2 m^(2). The thickness of the glass is

1.	The area of a glass window is 1.2 m^(2). The thickness of the glass is 2.2 mm. If the temperature outside is 36°C and the temperature inside is 26°, calculate the heat flowing into the room every hour. Thermal conductivity of glass is 0.8 Wm^(-1) K^(-1).
Answer» Solution :Area `= A= 1.2 m^(2)` Thickness of GLASS `= x = 2.2 " mm" = 2.2 xx 10^(-3) "m"` Temperature difference `= theta_1 - theta_2 = 36 - 26 = 10^(@) C` `= 10K` THERMAL conductivity of glass = K `=0.8 Wm^(-1) K^(-1)` Time `= t =1` hour `= 3600 s` Quantity of HEAT flowing in one hour `= ( KA ( theta_1 - theta_2 ) t)/( x ) = (0.8 xx 1.2 xx 10 xx3600)/( 2.2 xx 10^(-3) )` `= 1.57 xx 10^(7)` J per hour