As a star forms, the proto-stellar cloud contracts gradually over a period of millions to many tens of millions of years, depending upon the mass of the cloud. During this period, the cloud radiates away energy as thermal emission. However, the cloud becomes hotter as it contracts, so its thermal energy (the kinetic energy of particles due to thermal motions) goes up. An additional source of energy must be present in order for energy to be conserved. What is this source of energy during the contraction process?
The additional source of energy in the process of star formation is the gravitational potential energy which makes the cloud to contract as opposed to the expanding kinetic energy, hence conserving the energy according to the virial theorem.
As a star forms, the proto-stellar cloud contracts gradually over a period of millions to many...
10. Write a one-page summary of the attached paper? INTRODUCTION Many problems can develop in activated sludge operation that adversely affect effluent quality with origins in the engineering, hydraulic and microbiological components of the process. The real "heart" of the activated sludge system is the development and maintenance of a mixed microbial culture (activated sludge) that treats wastewater and which can be managed. One definition of a wastewater treatment plant operator is a "bug farmer", one who controls the aeration...