AP Physics
Conservation of Thermal Energy
Substance Specific Heat
(J/kg  C) aluminum 900 copper glass gold iron
387
837
129
448
1)
2) lead silver
128
234
Note: For the following problems, neglect any heat transfer to or from the surroundings.
A 400.0 g iron horseshoe initially at 500.0
 C is dropped into a bucket containing 20.0 kg of water at 22  C. What is the equilibrium temperature?
A 400.0 g sample of an unknown liquid at 80.0
 C is poured into 400.0 g of water at
40.0
 C. The final equilibrium temperature of the mixture is 49.0
 C. What is the specific heat of the liquid?
3) What mass of water at 25  C must be allowed to reach thermal equilibrium with a 3.0 kg gold bar at 100  C in order to lower the temperature of the bar to 50  C?
4) A block of copper of mass 200.0 g at a temperature of 90.0
 C is dropped into 400.0 g of water at 27  C. The water is contained in a 300.0 g glass container that remains in thermal equilibrium with the water. What is the final temperature of the mixture?
5) An aluminum cup contains 225 g of water at 27  C. A 400.0 g sample of silver at an initial temperature of 87  C is placed into the water. A 40.0 g copper stirrer initially sitting in the water is used to stir the mixture until it reaches it final equilibrium temperature of 32  C. Calculate the mass of the aluminum cup.
6) In a foundry operation, molten lead of mass 90.0 g at 327.3
 C is poured into an iron casting block that has a mass of 300.0 g and initially at 20.0
 C. What is the equilibrium temperature of the system?
1) 23  C
4) 29.4
 C
2) 1215 J/kg  C
5) 80.3 g
3) 185 g
6) 44.2
 C