Fields in Physics
This page delves into the concept of fields in physics, focusing on scalar and vector fields. It provides clear definitions and explanations of these fundamental concepts, which are crucial for understanding many areas of physics.
A field is defined as a physical quantity scalarorvector determined at each point in a given space. The page distinguishes between scalar and vector fields:
Definition: A scalar field is defined by a value associated with a unit at each point in the considered space.
Definition: A vector field is defined by a vector direction,sense,magnitude,andunit at each point.
The concept of field lines is introduced for vector fields. Field lines are tangent to the field vector at each point and are oriented in the same direction as the vector.
The page then focuses on two specific types of fields: the electrostatic field and the gravitational field.
The electrostatic field, denoted as E, is created by an object with an electric charge. Its magnitude is given by the equation E = k × Q / d², where Q is the source charge and d is the distance from the charge.
Highlight: The electrostatic field depends only on the source charge and the distance from it, not on the test charge placed in the field.
Similarly, the gravitational field, denoted as g, is created by an object with mass. Its magnitude is given by the equation g = G × M / d², where M is the source mass and d is the distance from the mass.
Example: The Earth creates a gravitational field that affects objects near its surface, resulting in the familiar force of gravity.
