First Principles - Sustainable Design: The Science of Sustainability and Green Engineering - page 54

and personal computers. Harmon argues that biomimicry is a “Gestalt shift of
humanity.”
Gestalt does not translate well from German, but reflects that there is a
dynamic beyond the sum of the parts. In fact, humanity itself is a community
beyond adding the individual contributions of each member. It seems that
early in the twentieth century, psychologists were suffering from many of the
same problems as those of designers. In particular, they understood that human
beings are more than the sum of their actions but the contemporary models did
not allow for such synergy. Behaviorists such as John Broadus Watson treated
human beings as a set of reactions to various stimuli in the environment,
whereas Gestalt psychologists saw people as much more than that. Humans
are integrated wholes, more than can be characterized by analyzing the parts.
Thus, Harmon argues that by looking “at what nature can do and reproducing
it faithfully, ... we can solve just about any problem on earth.”

Power and Efficiency

The amount of work done per unit time is power ( P ). Like energy, power is a
scalar quantity:

W

P = (2.6)

t

Power can also be expressed as a function of force and velocity:

P = F v (2.7)

Time for a few more problems:

Green Physics Example 3 Oxides of nitrogen (NO x ) are air pollutants. Some of
these compounds cause diseases, but they are also important because they are part
of the chemical reaction that leads to the formation of ozone, which causes lung
problems and is a key ingredient of summertime smog in the lower troposphere.

(a) The emission of NO x from an older car's exhaust is 100 mg per kilome-
ter traveled. If this increases by 10 mg km − 1 for each additional horsepower
expended, how much additional NO x would be released if the car traveling
100 km h − 1

supplies a constant horizontal force of 50 newtons (N) to carry a

trailer?