Describing Fields
Learning Objectives
- Gravitational fields
- Gravitational potential energy
- Gravitational potential
- Electrostatic fields
- Electric potential
- Field lines
- Equipotential surfaces
- Representing sources of mass and charge, lines of electric and gravitational force, and field patterns using an appropriate symbolism
- Mapping fields using potential
- Describing the connection between equipotential surfaces and field lines
- Describe field patterns where sources are masses or charges.
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Describe the connection between equipotential surfaces and field lines.
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Understand the concept of electric and gravitational potential
Field in General
Field is a region in which each point is affected by a force. In another world, field describes the impact produced by a massive body. For example, objects fall to the ground because they are affected by the force of earth's gravitational field, electron accelerates in a battery because they are affected by the force of electric field.
Gravitational Field
- The gravitational field is the gravitational force per unit mass that would be exerted on a small mass at that point
- It explains the influences that a massive body extends into the space around itself.
Gravitational Potential Energy
- The gravitational potential energy of two bodies is the work that was done in bringing the bodies to their present position from when they were infinitely far apart.
Gravitational Potential
- The gravitational potential at a point P in a gravitational field is the work done per unit mass in bringing a small point mass m from infinity to point P.
Electric Field
Electric Field Line
- "Like repel and opposite attract," meaning that opposite charges attractive each other while same charges repel each other.
- Opposite charge radiates outward and negative charge radiates inward.
- Charge density is represented the number of field lines.
Field line between two same charges
Field line between two oppositely charged particles
Electric Potential
Equipotential Surface
- An equipotential surface consists of those points that have the same potential.
- In a graph showing the variation with distance of the potential, the slope (gradient) of the graph is the magnitude of the field strength.This applies to both gravitational and electric fields.
