Author Question: Some properties of glass are listed here. Density: 2300 kg/m3 Specific heat: 840 J/kg C ... (Read 152 times)

silviawilliams41 · **on:** Jul 29, 2018

Some properties of glass are listed here.

Density: 2300 kg/m3
Specific heat: 840 J/kg C
Coefficient of linear thermal expansion: 8.5 10-6 (C)-1
Thermal conductivity: 0.80 W/(m C)

A glass window pane is 2.7 m high, 2.4 m wide, and 2.0 mm thick. The temperature at the inner surface of the glass is and at the outer surface 4.0C. How much heat is lost each hour through the window under steady state conditions?
A) 1.7 108 J
B) 1.7 105 J
C) 4.7 104 J
D) 4.7 101 J
E) 1.7 106 J

Question 2

The walls of an ice chest are made of 2.00-mm-thick insulation having a thermal conductivity 0.00300 W/m K.

The total surface area of the ice chest is 1.20 m2. If 4.00 kg of ice at 0.00C are placed in the chest and the temperature of the outside surface of the chest is 20.0C, how long does it take the ice to melt under steady state conditions? The latent heat of fusion of water is 79.6 cal/g = 334 kJ/kg.
A) 4.22 h
B) 22.1 h
C) 17.6 h
D) 1.33 d
E) 10.3 h