Heat energy how much heat is dissipated out of the

heat energy, how much heat is dissipated out of the system, and how much energy is
needed to increase the internal energy of the system we use the equation: Internal
energy equals heat minus work (∆U = Q –
1. First law of thermodynamics stated that energy is not created nor destroyed
into something else. This is based on the process that the change or to increase
the internal energy is equal to the amount of heat flowing the system minus the
net work done by the system.
2. Internal energy is the sum of the mechanical potential and kinetic energies of
the particles in the system.
3.
Adiabatic process - when the heat transfer of the system is equal to zero or no
heat transfer at all since energy is used exclusively for work
.
What’s More
Normally, heat transfer takes place from high temperature to low temperature or
from hot to cold, which does not require mechanical energy to occur. How about the
transfer of heat from low to high temperature? Would this be possible? Yes, it is through
the use of a heat pump, an instrument used to reverse the natural flow of heat or
spontaneous process of heat transfer into a non-spontaneous process by
absorbing heat from a cold space and releasing it to a warmer one. This process requires
mechanical energy input to take place. This supports the Second Law of
Thermodynamics which states that heat will never flow from a cold temperature to a hot
temperature object.
W).
Given:
Q = unknown; ∆U = 80 J; W = -120J
Solution: Q = ∆U + W
Q = 80 J + (-120 J)
Q = - 40 J
Objective:

5
• Explain how heat pumps work as exemplified by an air-condition unit and a
refrigerator.
Materials:
Diagrams of refrigerator and air condition cycle
A. Refrigeration cooling cycle process
Figure 3. Refrigeration cooling cycle process
Procedure:
Study the diagram above and its part. Answer the following questions (you may
use any search engine).
Guide Questions:
Q 5. Explain how a refrigerator work.
Q 6. How does an evaporator work?
Q 7. What happen to the vapor in the compressor?
Q 8. What is the function of the condenser?
Q 9. What happens to the pressure and heat in the evaporator?
Guide questions:
Q 10. How does an air conditioning unit function?
Q 11 . Why does an air conditioning unit need mechanical input of energy to function?
Q 12. How will you increase the efficiency rate of an air conditioning unit?
Q 13. Why is it necessary for a heat pump like refrigerator and air condition unit to
have an inverter?
Heat transfer in a refrigerator and air condition unit shows a spontaneous
process that required a mechanical external energy. Since heat flows from lower
temperature to higher temperature. This conforms to the second law of thermodynamics
which states that heat will never flow from cold temperature to a hot temperature object.
That is why a heat pump is needed. A heat pump is an instrument that reverse the
direction of the heat flow. Just like a refrigerator and air condition unit.