A. power plants burn coal. A fossil-fuel power plant is one that burns fossil fuels such as coal, natural gas or petroleum (oil) to produce electricity.
b. Fossil fuels are called so because they have been derived from fossils, which were formed millions of years ago during the time of the dinosaurs. They are fossilized organic remains that over millions of years have been converted to oil, gas, and coal.
C. they are generally classified as non-renewable resources because they take millions of years to form and known viable reserves are being depleted much faster than new ones are generated.
5.
a. Gravitational potential energy and work done
If an object is lifted, work is done against the force of gravity.
When work is done energy is transferred to the object and it gains gravitational potential energy.
If the object falls from that height, the same amount of work would have to be done by the force of gravity to bring it back to the Earth’s surface.
If an object at a certain height has 2000 J of gravitational potential energy, we can say that:
2000 J of work has been done in getting the object to that height from the ground
and
2000 J of work would have to be done to bring it back to the ground.
Answer:
Explanation:
a. Internal energy and the relative specific volume at 
are determined from A-17:
.
The relative specific volume at 
is calculated from the compression ratio:
#from this, the temperature and enthalpy at state 2, can be determined using interpolations 
and 
. The specific volume at can then be determined as:
Specific volume,:
The pressures at 
is:
.The thermal efficiency=> maximum temperature at 
can be obtained from the expansion work at constant pressure during 
b.Relative SV and enthalpy at are obtained for the given temperature with interpolation with data from A-17 :
Relative SV at 
is
=
Thermal efficiency occurs when the heat loss is equal to the internal energy decrease and heat gain equal to enthalpy increase;
Hence, the thermal efficiency is 0.563
c. The mean relative pressure is calculated from its standard definition:
Hence, the mean effective relative pressure is 674.95kPa
You must observe the object twice.
-- Look at it the first time, and make a mark where it is.
-- After some time has passed, look at the object again, and
make another mark at the place where it is.
-- At your convenience, take out your ruler, and measure the
distance between the two marks.
What you'll have is the object's "displacement" during that period
of time ... the distance between the start-point and end-point.
Technically, you won't know the actual distance it has traveled
during that time, because you don't know the route it took.
