The correct answer is
C. reduce the friction between its moving parts
In fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.
Potential energy<span> is the </span>energy<span> that is stored in an object due to its position relative to some zero position. It is calculated by the expression PE = mgh where mg is the weight of the book and h is the height. It is calculated as follows:
PE = 50(1) = 50 J
</span>PE = 50(1.5) = 75 J
PE = 50(2) = 100 J
History is open to ongoing and changing interpretations because changing <span>values limit interpretation.
So your answer is A.</span>
