文档介绍：Mechanical Energy
JOSEPH PRIEST
Miami University
Oxford, Ohio, United States
The physical concepts of work, ic energy as
1. Mechanical Energy energy due to motion, and potential energy as energy
2. Work due to some favorable position are discussed in this
3. ic Energy article. Added together, ic energy and potential
4. Work–Energy Principle energy are called mechanical energy. In the absence
5. Conservative and Nonconservative Forces of nonconservative forces (., friction), the mechan-
6. Potential Energy ical energy of an object does not change with time
7. Conservation of Mechanical Energy and is said to be conserved. The motion of a child on
a swing is discussed in light of the conservation of
8. Energy Conversion
energy. A wide variety of important types of ic
9. Applications of Mechanical Energy
energy are derived from the conversion of other
forms of energy. Such is the case in a hydroelectric
Glossary system that is discussed in some detail in the article.
conservative force When work done by a force is
zero for every path that ends up at the starting point.
energy The capacity or ability of an object to do work, 1. MECHANICAL ENERGY
with the joule (J) as the measuring unit.
Hooke’s Law When an elastic object exerts a force
proportional to the displacement of the object and in Energy has some meaning to everyone. A person
the opposite direction. often does not have energy following a bout with a
joule (J) The unit of work and energy; a force of 1 newton cold. Concerns about depletion of our energy
(N) acting over a distance of 1 m does 1 J of work. resources, solar energy, wind energy, and nuclear
ic energy The ability of an object to do work as a energy mon topics in newspapers and on
result of having mass and speed; in terms of mass (m) television. Although energy has several meanings, in a
1 2
and speed (v), ic energy is 2mv
physical sense it is considered ‘‘a capacity for doing
mechanical energy The sum o