Consider three layers of a wall. The first layer is plaster 1.0 cm thick ( R = 0
ID: 1333094 • Letter: C
Question
Consider three layers of a wall. The first layer is plaster 1.0 cm thick (R = 0.033 SI units), the second layer is fiberglass insulation 8.9 cm thick (R = 2.97), and the outside layer is wood 3.0 cm thick (R = 0.33). What is the heat loss through one square meter of wall if the inside temperature is 20 °C and the outside is 10°C?
A) 9.0 watts
B) 90watts
C)5.2watts
D)23 watts
If we boil away 0.25 kg of water, how much entropy do we add to the universe in the boiling process? The latent heat of vaporization for water is 2260 kJ/kg.
a) 1.5J/K
B)2.8J/K
C) 5650 J/K
D) 1500 J/K
Breaking an egg is an example of increasing
A)thermodynamic entophy
B)potential entrophy
C) momentum entrophy
D)configuration entrophy
Explanation / Answer
1)
2) D)1500 J/K
Increase in entropy, dS = Q/T
= m*Lv/T
= 0.25*2260*10^3/(273+100)
= 1514 J/K
3) D)configuration entrophy