File Name: potential energy and conservation of energy .zip
In physical sciences , mechanical energy is the sum of potential energy and kinetic energy. It is the macroscopic energy associated with a system.
Lesson 2 has thus far focused on how to analyze motion situations using the work and energy relationship. The relationship could be summarized by the following statements:. There is a relationship between work and mechanical energy change. Whenever work is done upon an object by an external or nonconservative force , there will be a change in the total mechanical energy of the object. If only internal forces are doing work no work done by external forces , there is no change in total mechanical energy; the total mechanical energy is said to be "conserved.
Application and Practice Questions
Potential Energy. Chapter 7. Young, Hugh D. Freedman, and A. Lewis Ford. ISBN: From Lecture 11 of 8.
When scientists use the term energy, there are a variety of definitions, but the commonly taught definition in school science is the capacity to do work. What does this definition mean, and how does it help us think about our human energy systems? This teacher guide is designed to familiarize teachers with both the technical terminology about energy, and the energy efficiency and conservation issues that have become so important in recent years. There are many ideas currently being discussed about sources of alternative energy and their relationship to energy efficiency as well as the environment. Being armed with a greater understanding of energy allows us to make wiser choices in our personal lives, as well as in our communities.
Can Law of Conservation of Energy Be Broken?
Work is done by a force, and some forces, such as weight, have special characteristics. A conservative force is one, like the gravitational force, for which work done by or against it depends only on the starting and ending points of a motion and not on the path taken. For example, when you wind up a toy, an egg timer, or an old-fashioned watch, you do work against its spring and store energy in the spring. We treat these springs as ideal, in that we assume there is no friction and no production of thermal energy. This stored energy is recoverable as work, and it is useful to think of it as potential energy contained in the spring. Indeed, the reason that the spring has this characteristic is that its force is conservative.
Work is done by a force, and some forces, such as weight, have special characteristics. A conservative force is one, like the gravitational force, for which work done by or against it depends only on the starting and ending points of a motion and not on the path taken. We can define a potential energy PE for any conservative force, just as we did for the gravitational force.
Samuel J. Conceptual Questions 8. Explain whether this is true for the potential energy of a system. The force exerted by a diving board is conservative, provided the internal friction is negligible.
The law of conservation of energy is an empirical law of physics. It states that the total amount of energy in an isolated system remains constant over time. And it is impossible to break. However, three of evidence presented in this paper cannot be explained by the Law of conservation of energy.