I can think of two arguments that explain why work should be positive or negative. I could see work as positive because the system does positive work on the environment. An analogy could be that it applies a fo
Gas by doing negative work(losing heat), say accelerating a piston violates 2nd law of thermo, because kinetic energy of piston can be used to make other gas hotter, thus in summary one gas gets colder, other one gets hotter and this by simple piston!!! Reply Science news on Phys.org...
The latter calculation can be for two surfaces in an inert medium such as dry air, or in water or saturated vapour. All this assumes that the mechanism of adhesion is physical adsorption. If the work of adhesion is positive, then the bond is stable. Conversely, a negative work of ...
We analyze a discharging battery with a two-phase LiFePO4/FePO4 positive electrode (cathode) from a thermodynamic perspective and show that, compared to loosely-bound lithium in the negative electrode (anode), lithium in the ionic positive electrode is more strongly bonded, moves there in an ...
Describe the conditions when the work done by a force is (a) positive or (b) negative. Explain with help of examples. Explain, using work and energy ideas, how a child pumps a swing up to large amplitudes from a rest position.
Summary6.Work,Energy&Power摘要6.功,能和功率-ckw ShortVersion:6.Work,Energy&Power 短版:6.功，能和功率 UsefulnessforStudyingEnergy 研究能量的好處 •Alternativewaystodescribemotion提供另一種方法來描述哂:–Conservationofenergy能量守恆.–Hamiltonianformulism漢美頓的做法.•Extensiontonon-mechanicalstudies...
(1997)proposed, in the same sense that the fourth principle of thermodynamics does not point to negative entropy in which everything tends toward destruction as time flows. The passing of time is seen as a positive and creative enabler. In other words, time is intensive, not linear, and ...
It is evident that cannot be both strictly positive in general. For example, in the case of the same instantaneous pseudo-temperatures, as when and Tχ(τ) ≠ 0, from we obtain for . In general, it is not true that the finite variation becomes nonnegative in the absence of ...
Generally, operational window of turbomachines locates at high rotational speeds, which are far above the operation speeds of positive displacement machines. Large flow rates, low pressure ratios, and large machine sizes characterise turbomachines’ performance and geometries. Because of the difficulty to...
or force component is opposite to that of the displacement; then work is said to be doneonthe agent andbythe moving body. From the point of view of energy, an agent doing positive work is losing energy to the body on which the work is done, and one doing negative work is gaining ...