Material use rates rose substantially in the twentieth century. ...

[itsmyluck]

Material use rates rose substantially in the twentieth century.
 
  What will be an ideal response?

Question 2

Evaporation losses from impoundments could be countered by release of millions of white Ping Pong balls to float on the water's surface.
 
  The white surface of the balls would reflect most of the incident sunlight, and reduce evaporative losses substantially. Assess the feasibility of such a measure in the real world.

[tjayeee]

Answer to Question 1

This is quite true. The twentieth century was the century of materials. The twenty
first century may well be the century of the service and information sectors, at least in the
developed countries.

Answer to Question 2

The process is probably feasible. The student should try to justify statements as
to feasibility with realistic estimates where possible. Each ball is approximately 25 mm
across, so a reservoir with an area of 250 square kilometers could be covered with 10 billion
Ping-Pong balls. This would cost less than 100 million. However, the use of reservoirs as
vacation sites or as beautiful outdoor scenery would certainly suffer. The balls would float,
so that movements of water through the reservoir would not be affected. It would be
necessary to make sure that the balls do not run through the turbine

[itsmyluck]

Thanks

[tjayeee]

Welcome