Question

1. A perpetual motion machine is a machine or device which performs work without an energy input. Is this possible? Explain why or why not using the principles of work, energy and power.

2. A machine is used to change energy in many of its forms into useful work. Draw a diagram of this process, like the one used in class. List the terms in this diagram, explaining how and why this process is not 100% efficient.

Answer 1

1)A perpetual motion machine is not possible. As the PPM 1 is type of machine which performs works with any input of energy.
From the First law of thermodynamics it is quite clear that energy can neither be created nor be destroyed, only it transfer
from one form to another. Hence a PPM violates the law of conservation of energy , therefore it is impossible to build.
It can't be explained with work , energy and power principle, as this principle doesn't state the the conservation of energy.

2)

Since there is always some of the input energy is used in order to heat up or change its initial state or lost due to friction the system. Ultimately the output that we get is always is lower than the input. Hence the efficiency is not 100%.