TABLE OF CONTENTS Force is a basic concept in physics. An unbalanced sum of forces, a net force, will cause a body to accelerate. That is, the object s velocity will change magnitude or size, in this case how fast it is moving, and/or the direction it is traveling. Forces are required for objects to change from a state of rest to a state of motion and back to rest, or to change their state of motion.
About 150 years ago Michael Faraday proposed that, in addition to the forces that exist because objects come into contact with each other (contact forces for short), there are also forces caused by fields. The reasoning goes like this: an object creates a field, another object interacts with this field, and this interaction leads to a force. While this seems a bit contrived, it has turned out to be a very fruitful concept. This chapter will briefly review forces in general and then focus on electrostatic forces since they are of primary importance in later chapters. The following questions will be addressed:
What is a force and how is it related to acceleration?
How are entities such as forces that have both magnitude and direction represented?
What is the nature of the electric force between two objects and what is the electric field?
What is the electric field in some technologically important geometries?
What happens when material objects are placed in an electric field?
We experience forces every day. Examples include:
Gravity as seen...
