Thermal Behavior of Matter and Heat Engines - Department of ...

Substance
Specific heat, c, [J/(kg⋅K)]
Water 4186
Ice 2090
Steam 2010
Aluminum 900
Glass 703
Iron (steel) 448
Copper 387
Silver 234
Gold 129
Lead 128
Table: Specific heats at atmospheric temperature and pressure
Example
550 g of water at 32 o C is poured into a 210-g aluminum can with an initial
temperature of 15 o C. Find the final temperature of the system, assuming no heat is
exchanged with the surroundings.
Answer:
Method 1:
The heat flow out of water: Q = m c ( T − T ) .
The heat flow into the aluminum: Q = m c T − T ) .
W
W
a
W
W
a a
(
a
Conservation of energy implies
Q = Q , which gives T = 31 o C.
W
a
Method 2:
The heat flow out of water: Q = m c T − T ) .
W
W
W
(
W
The heat flow into the aluminum: Q = m c T − T ) .
a
a a
(
a
Conservation of energy implies Q Q = 0 , which gives T = 31 o C.
W
+ a
8