Answer to Question 1
This probably occurred because of the cost of transportation, which was greater
for steel cans, and because steel cans changed the taste of beer (and presumably other
drinks, though it was less obvious). The beer bottlers adopted aluminum cans and because
of economies of scale, other bottlers did as well.
Answer to Question 2
The residue, if left in place, can contribute to soil fertility. Retention of organic
matter enhances subsequent productivity. Removal of all ground cover, characteristic of
clearcutting, can have adverse effects on the soil and hinder reestablishment of the local
ecosystem.
Basic overview of energy and human life.
Activation energy graph
Gibs free energy for hydrolysis of some phosphate compounds
Generating Energy from Glucose When your body needs to break down glucose
Physics: Power, Energy and Time
Energy in a Circular Orbit