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Conservation of Energy (12.4) Notes
Energy
Potential energy can become ____________ energy, and kinetic energy can _____________ potential
Trans-
energy. Label the rollercoaster to show where the car has the greatest and least amount of potential and
formations
kinetic energy.
Give two other examples in which potential energy is being transformed into kinetic energy and/or viseversa.
1. ____________________________________________________________________
2. ____________________________________________________________________
The Law of
State the law in its simplest form: _______________________________________________
Conservation
of Energy
The law of conservation of energy requires that at any given time, the __________ energy
should be the ____________. Whenever the total energy in a system increases, it must be due to
energy that enters the system from an _______________ source. None of the energy disappears;
it just changes __________.
To make studying a situation easier, scientists often limit their view to a small area or a small
number of objects. These boundaries define a ____________. When the flow of energy into and
out of a system is small enough that it can be ignored, the system is called a _____________
system. Most system are __________ systems, which exchange energy with the space that
surrounds them.
Efficiency
of Machines
Not all of the work done by a machine is _____________ work. Efficiency is the __________ of
useful work out to work in, and is usually expressed as a percentage.
Efficiency Equation:
Perpetual motion machines (machines designed to go on forever without any input of energy)
are _____________________ due to friction and air resistance.