Jackson: Viewed from a scientist’s standpoint, all
of the energy contained in fuel either now or in the future becomes heat. Some
of the heat is used directly or produces useful work. The rest is lost or
rejected. That is to say, it is radiated into the atmosphere from the engines,
motors, furnaces, power lines, television sets, boilers and all the other
energy-consuming machinery that makes our wheels go
around. Browning: It is necessary to improve the
efficiency with which we use energy in order to do more work. But improvement
cannot come overnight, and there are limits beyond which not even science can
help. According to the Center for Strategic and International studies, about
three quarters of the energy we use to move things, including ourselves,
accomplishes no useful work. Jeffry: In terms of
efficiency, buses, trains, and other forms of public transportation may be using
energy more efficiently than private automobiles. Unless private automobiles
call operate at near capacity, their overall efficiency is poor. For example, an
urban bus carrying 36 passengers may achieve an efficiency of around 120
passenger-miles per gallon of gasoline. But buses are not always fully loaded,
and sometimes they carry no passengers at all. Vandenberg:
It is true that buses can sometimes run without passengers. City trains
seem to be very efficient, but they suffer the same shortcomings as buses and
cost more. Except for rush hours, commuter trains seldom run at full capacity.
This wastes even more energy and is more than the management can afford. As a
result, commuter trains are truly practical only in places where there are a lot
of people. Nathan: For some people, mass
transportation may serve their needs. For others, a combination of mass
transportation and private transportation may be preferable. Better design and
wise use of both mass transportation systems and private vehicles will play an
important part in helping us make fuller use of energy for
transportation. Now match each of the people (61 to 65) to
the appropriate statement. Note: there are two extra
statements. Statements [A] Public transportation is usually
more energy-efficient. [B] The efficiency of the city train depends on the
size of population. [C] City trains and buses have different faults to
overcome. [D] Private cars usually run at full capacity. [E] No fuel
energy is fully used. [F] A combined means of transport can help increase
energy efficiency. [G] Problems of energy loss can never be completely
solved. Jackson