Chapter 6
Work and Energy
By Boundless
The work done by a constant force is proportional to the force applied times the displacement of the object.
![Thumbnail](../../../../../figures.boundless-cdn.com/16565/square/sp2.gif)
A force does not have to, and rarely does, act on an object parallel to the direction of motion.
![Thumbnail](../../../../../figures.boundless-cdn.com/17118/square/cf4.gif)
Conservative force—a force with the property that the work done in moving a particle between two points is independent of the path it takes.
![Thumbnail](../../../../../figures.boundless-cdn.com/17119/square/iaeval-archery-reenactment.jpeg)
Potential energy is the energy difference between the energy of an object in a given position and its energy at a reference position.
![Thumbnail](../../../../../figures.boundless-cdn.com/17121/square/er-dam-nevada-luftaufnahme.jpeg)
Gravitational energy is the potential energy associated with gravitational force, as work is required to move objects against gravity.
![Thumbnail](../../../../../figures.boundless-cdn.com/21968/square/hookeslawforspring-english.jpg)
When a spring is stretched/compressed from its equilibrium position by x, its potential energy is give as
![Thumbnail](../../../../../figures.boundless-cdn.com/17120/square/orbital-motion.gif)
Conservation of mechanical energy states that the mechanical energy of an isolated system remains constant without friction.
![Thumbnail](../../../../../figures.boundless-cdn.com/17439/square/wooden-roller-coaster-txgi.jpeg)
To solve a conservation of energy problem determine the system of interest, apply law of conservation of energy, and solve for the unknown.
![Thumbnail](../../../../../figures.boundless-cdn.com/17124/square/figure-08-05-04a.jpeg)
In the presence of dissipative forces, total mechanical energy changes by exactly the amount of work done by nonconservative forces (Wc).
![Thumbnail](../../../../../figures.boundless-cdn.com/12251/square/nagasakibomb.jpeg)
Thermal, chemical, electric, radiant, nuclear, magnetic, elastic, sound, mechanical, luminous, and mass are forms that energy can exist in.
![Thumbnail](../../../../../figures.boundless-cdn.com/17227/square/oscillating-pendulum.gif)
Energy transformation occurs when energy is changed from one form to another, and is a consequence of the first law of thermodynamics.
![Thumbnail](../../../../../figures.boundless-cdn.com/17232/square/pecurvewithbars.jpg)
A potential energy curve plots potential energy as a function of position; equipotential lines trace lines of equal potential energy.