HEAT
ENERGY AND SPECIFIC HEAT CAPACITY
Data:
Specific heat capacities:
Water
4200 J/kgoC Copper
400 J/kgoC Aluminium 900 J/kgoC Concrete
3300 J/kgoC Lead
126 J/kgoC
1. Should saucepans be made of material
with a high or low specific heat capacity? Explain your answer.
2. How much heat energy is needed to raise
the temperature of a 200 g piece of lead by 250 oC?
3. A 150 g potato cools from 100 oC
to 50 oC. If the specific heat capacity of potato is 2000 J/kgoC
how much heat does the potato loose?
4. A 300 g copper saucepan contains 1 kg
of water. If the water and the saucepan are heated from 20 oC to 100
oC calculate:
(a) how much heat energy the water gains
(b) how much heat energy the saucepan
gains
5. A small piece of aluminium of mass 50 g
is used on a circuit that has a normal temperature of 20 oC. If the
piece of aluminium must not get hotter than 150 oC how much heat
energy can it absorb?
6. Why does land heat up more quickly than
sea water and how does this help to explain land and sea breezes?
7. Why do you think that houses built of
stone take a long time to warm up but once they are warm they stay warm for a
long time?
8. Why is water such a good coolant?
9. Tea pots made of china should be heated
with hot water before making the tea. This is not necessary with steel ones.
Explain this.
10. A pie is cooked in an oven at 200 oC.
The aluminium film that covered the pie
can be touched soon after it is removed while the pie is still
dangerously hot. Explain this.
