Btu and Calorie
Calorie
50ºF
10ºC
11ºC
+
1 gram
of water
at 10ºC
+
Btu
+
51ºF
=
=
1 calorie
of heat
=
1 gram
of water
at 11ºC
1 pound
of water
at 50ºF
+
1 Btu
of heat
=
1 pound
of water
at 51ºC
Solving Problems:
Heat Equation
HEAT EQUATION
Heat energy
(joules)
joule
Specific heat ( kgºC )
E = mCp (T2 - T1 )
Mass (kg)
Change in temperature (ºC)
Specific Heat of Silver and Aluminum
Silver
1 kilogram
Specific heat: 235 J/kgºC
Heavier atoms mean fewer
atoms per kilogram
Aluminum
1 kilogram
Specific heat: 900 J/kgºC
Lighter atoms mean more
atoms per kilogram
• Energy is spread
over fewer atoms
• Energy is spread
over more atoms
• More energy per atom
• Less energy per atom
• Higher temperature
gain per joule
(lower specific heat)
• Lower temperature
gain per joule
(higher specific heat)
Thermal Conductors and Insulators