Embedded Files
Outcomes
Outcomes
Use the term ‘field’ to describe forces acting at a distance.
Know that a field’s force reduces as you move away.
Identify ways objects acquire an electrostatic charge.
Describe the behaviour of charged objects when they are brought close to one another
Know dust storms and lightning strikes in severe weather are examples of electrostatic forces
Electric Fields
Electric Fields
Halt! This science fiction image shows a human hand surrounded by a green force field. It’s supposed to represent an electric field generated by a hand. What is an electric field? Read on to find out.
What Is an Electric Field?
What Is an Electric Field?
An electric field is a space around a charged particle where the particle exerts electric force on other charged particles. Because of their force fields, charged particles can exert force on each other without actually touching. Electric fields are generally represented by arrows, as you can see in the Figure below (Links to an external site.)Links to an external site.. The arrows show the direction of electric force around a positive particle and a negative particle. For an animated diagram, go to this URL: http://ocw.mit.edu/ans7870/8/8.02T/f04/visualizations/electrostatics/15-CreateField/CreateField_640.mpg (Links to an external site.)Links to an external site.
Interacting Electric Fields
Interacting Electric Fields
When charged particles are close enough to exert force on each other, their electric fields interact. This is illustrated in the Figure below (Links to an external site.)Links to an external site.. The lines of force bend together when particles with different charges attract each other. The lines bend apart when particles with like charges repel each other.
At the following URL, play “Electric Field of Dreams” to experience interacting fields of two or more charged particles. http://www.cabrillo.edu/~jmccullough/Physics/Electric_Forces_Fields.html (Links to an external site.)Links to an external site.
Note: +q = positive charge and –q = negative charge
Q: What would the lines of force look like around two negative particles?
A: They would look like the lines around two positive particles, except the arrows would point toward, rather than away from, the negative particles.
Summary
Summary
An electric field is a space surrounding a charged particle where the particle exerts electric force.
When charged particles are close enough to exert force on each other, their electric fields interact. Particles with opposite charges attract each other. Particles with like charges repel each other.
Vocabulary
Vocabulary
electric field: Space around a charged particle where the particle exerts electric force on other particles.
Activities:
Activities:
Practice
Practice
Play electric field hockey at the following URL until you score at least one goal. Then write a brief paragraph describing what you did to score a goal. https://phet.colorado.edu/en/simulation/electric-hockey
Review
Review
What is an electric field?
Create a sketch showing how the electric fields of two negatively charged particles interact.
Google Sites
Report abuse