Describe how conservation of energy relates to the first law of thermodynamics.
Identify instances of the first law of thermodynamics working in everyday situations, including biological metabolism.
Calculate changes in the internal energy of a system, after accounting for heat transfer and work done.
The information presented in this section supports the following AP® learning objectives and science practices:
4.C.3.1 The student is able to make predictions about the direction of energy transfer due to temperature differences based on interactions at the microscopic level.
(S.P. 6.1)
5.B.4.1 The student is able to describe and make predictions about the internal energy of systems.
(S.P. 6.4, 7.2)
5.B.7.1 The student is able to predict qualitative changes in the internal energy of a thermodynamic system involving transfer of energy due to heat or work done and justify those predictions in terms of conservation of energy principles.
(S.P. 6.4, 7.2)
If we are interested in how heat transfer is converted into doing work, then the conservation of energy principle is important. The first law of thermodynamics applies the conservation of energy principle to systems where heat transfer and doing work are the methods of transferring energy into and out of the system. The
first law of thermodynamics states that the change in internal energy of a system equals the net heat transfer
into the system minus the net work done
by the system. In equation form, the first law of thermodynamics is
Here
is the
change in internal energy
of the system.
is the
net heat transferred into the system —that is,
is the sum of all heat transfer into and out of the system.
is the
net work done by the system —that is,
is the sum of all work done on or by the system. We use the following sign conventions: if
is positive, then there is a net heat transfer into the system; if
is positive, then there is net work done by the system. So positive
adds energy to the system and positive
takes energy from the system. Thus
. Note also that if more heat transfer into the system occurs than work done, the difference is stored as internal energy. Heat engines are a good example of this—heat transfer into them takes place so that they can do work. (See
[link] .) We will now examine
,
, and
further.
is it possible to leave every good at the same level
Joseph
I don't think so. because check it, if the demand for chicken increases, people will no longer consume fish like they used to causing a fall in the demand for fish
Anuolu
is not really possible to let the value of a goods to be same at the same time.....
Salome
Suppose the inflation rate is 6%, does it mean that all the goods you purchase will cost
6% more than previous year? Provide with reasoning.
Not necessarily. To measure the inflation rate economists normally use an averaged price index of a basket of certain goods. So if you purchase goods included in the basket, you will notice that you pay 6% more, otherwise not necessarily.
Good day
How do I calculate this question: C= 100+5yd G= 2000 T= 2000 I(planned)=200.
Suppose the actual output is 3000. What is the level of planned expenditures at this level of output?
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Sekou
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Amisha
ahile becheclor ho
Amisha
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ani k kaam grnu hunxa tw
Amisha
belatari
Amisha
1st year ho
Amisha
nd u
Amisha
ahh
Amisha
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Amisha
ys
Amisha
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Amisha
money as unit of account means what?
Kalombe
A unit of account is something that can be used to value goods and services and make calculations
Jim
all of you please speak in English I can't understand you're language
Muhammad
I want to know how can we define macroeconomics in one line
Muhammad
it must be .9 or 0.9
no Mpc is greater than 1
Y=100+.9Y+50
Y-.9Y=150
0.1Y/0.1=150/0.1
Y=1500
Kalombe
Mercy is it clear?😋
Kalombe
hi can someone help me on this question
If a negative shocks shifts the IS curve to the left, what type of policy do you suggest so as to stabilize the level of output?
discuss your answer using appropriate graph.