PASCO ET-8782 Energy Transfer– Thermoelectric - Manual (Page 15)

Model No. ET-8782 Energy Transfer –Thermoelectric
15 ®
Experiment 1:
Teachers’ Notes–Conservation of Energy
and the First Law of Thermodynamics
This sample data is in the file “Conservation of Energy Data”.
Heat Pump Mode
Q
hot
= 172.8 J
Q
cold
+ W = 233.1 J
1) Most of the heat pumped out of the cold reservoir went into the hot reservoir. The heat
pumped into the hot reservoir is greater than the heat pumped out of the cold reservoir
because Q
hot
also includes the work done by the peltier.
2) Q
hot
< Q
cold
+ W. Some energy was lost. Part of it flowed through the insulator to the
environment. Part of it was dissipated in other parts of the circuit.
3) Q
hot
= Q
cold
+ W – E
lost
Heat Engine Mode
W
observed
= 0.572 J
Q
hot
– Q
cold
= 3.3 J
4) W
observed
< Q
hot
– Q
cold