Follow two steps below to derive Eq. (6): i. Insert the angular acceleration from Eq. (2) and the moment of inertia from Eq. (5) into RHS of Eq. (4) and find the friction in terms of these quantities. ii. Insert the friction obtained in i. into Eq. (3) and rearrange it to get Eq. (6)

Transfer of electrons. hope it !

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.

The sun's gravitational pull is weaker on the planets that are closer to it, i think.