1. 
The energy lost by the water is given by:

where
m = 3.0 kg = 3000 g is the mass of water
Cs = 4.179 J/g•°C is the specific heat
is the change in temperature
Substituting,

2. 
The energy added to the aluminium is given by:

where
m = 0.30 kg = 300 g is the mass of aluminium
Cs = 0.900 J/g•°C is the specific heat
is the change in temperature
Substituting,

3a. 
The temperature change of the water is given by

where
is the heat lost by the water
is the mass of water
Cs = 4.179 J/g•°C is the specific heat
Substituting,

3b. 
The temperature change of the copper is given by

where
is the heat added to the copper
is the mass of copper
Cs = 0.385 J/g•°C is the specific heat
Substituting,

4. 42.9 g
The mass of the water sample is given by

where
is the heat added
is the temperature change
Cs = 4.179 J/g•°C is the specific heat
Substituting,

5. 115.5 J
The heat used to heat the copper is given by:

where
m = 5.0 g is the mass of copper
Cs = 0.385 J/g•°C is the specific heat
is the change in temperature
Substituting,

6. 0.185 J/g•°C
The specific heat of iron is given by:

where
Q = -47 J is the heat released by the iron
m = 10.0 g is the mass of iron
is the change in temperature
Substituting,
