Fiveable
Fiveable

or

Log in

Find what you need to study


Light

Find what you need to study

8.2 Electric Charge

2 min readjune 7, 2020

Peter Apps

Peter Apps

Peter Apps

Peter Apps

Enduring Understanding 5.A

Certain quantities are conserved, in the sense that the changes of those quantities in a given system are always equal to the transfer of that quantity to or from the system by all possible interactions with other systems.

Enduring Understanding 1.B

is a property of an object or a system that affects its interactions with other objects or systems containing charge.

Essential Knowledge 1.B.2

There are only two kinds of . Neutral objects or systems contain equal quantities of positive and , with the exception of some fundamental particles that have no .

Interactions with Other Objects

Charged objects will attract or repel other objects. These interactions follow a simple rule: Likes Repel, Opposites Attract. If two objects have similar charges (both negative or both positive) they will repel each other. If the objects have opposite charges (one positive and one negative) they will attract each other. A neutral object will always be attracted to a charged object. To explore why this is, check out this PhET simulation.

Electric Fields

Note: AP Physics 1 doesn’t cover the idea of electric fields. This is included as a basis for discussing electric force in the next key idea. AP Physics 2 goes into much greater depth with electric and magnetic fields.

The region around a charged object can be described by an electric field. Electric field lines show the direction a will travel when placed near the charged object. If placed near a positive object it will be repelled, therefore the electric field lines point away from a positive object.

Likewise, the test charge will be attracted to a negative object and the field lines will point in. This is useful in visualizing the direction the will be acting in. The images below show some common arrangements, or check out this PhET simulation and create your own.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2FScreen%20Shot%202020-04-15%20at%209.28.38%20PM.png?alt=media&token=b9a864f3-5300-4dfc-9c0e-b09b52e584dd

🎥Watch: AP Physics 1 - Unit 8 Streams

Key Terms to Review (5)

Conserved Quantities

: Conserved quantities are physical properties that remain constant over time in a closed system, meaning they cannot be created or destroyed. They can only change form or be transferred between different objects within the system.

Electric charge

: Electric charge is a fundamental property of matter that determines how it interacts with electric fields. It can be positive or negative.

Electrostatic Force

: Electrostatic force refers to the attraction or repulsion between electrically charged objects due to their electric charges.

Negative Charge

: A negative charge refers to an excess of electrons on an object, resulting in an overall negative electrical charge.

Positive Charge

: Positive charge refers to an excess of protons or a deficiency of electrons in an object, resulting in a net positive electric charge. Objects with positive charge repel other positively charged objects and attract negatively charged objects.

8.2 Electric Charge

2 min readjune 7, 2020

Peter Apps

Peter Apps

Peter Apps

Peter Apps

Enduring Understanding 5.A

Certain quantities are conserved, in the sense that the changes of those quantities in a given system are always equal to the transfer of that quantity to or from the system by all possible interactions with other systems.

Enduring Understanding 1.B

is a property of an object or a system that affects its interactions with other objects or systems containing charge.

Essential Knowledge 1.B.2

There are only two kinds of . Neutral objects or systems contain equal quantities of positive and , with the exception of some fundamental particles that have no .

Interactions with Other Objects

Charged objects will attract or repel other objects. These interactions follow a simple rule: Likes Repel, Opposites Attract. If two objects have similar charges (both negative or both positive) they will repel each other. If the objects have opposite charges (one positive and one negative) they will attract each other. A neutral object will always be attracted to a charged object. To explore why this is, check out this PhET simulation.

Electric Fields

Note: AP Physics 1 doesn’t cover the idea of electric fields. This is included as a basis for discussing electric force in the next key idea. AP Physics 2 goes into much greater depth with electric and magnetic fields.

The region around a charged object can be described by an electric field. Electric field lines show the direction a will travel when placed near the charged object. If placed near a positive object it will be repelled, therefore the electric field lines point away from a positive object.

Likewise, the test charge will be attracted to a negative object and the field lines will point in. This is useful in visualizing the direction the will be acting in. The images below show some common arrangements, or check out this PhET simulation and create your own.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2FScreen%20Shot%202020-04-15%20at%209.28.38%20PM.png?alt=media&token=b9a864f3-5300-4dfc-9c0e-b09b52e584dd

🎥Watch: AP Physics 1 - Unit 8 Streams

Key Terms to Review (5)

Conserved Quantities

: Conserved quantities are physical properties that remain constant over time in a closed system, meaning they cannot be created or destroyed. They can only change form or be transferred between different objects within the system.

Electric charge

: Electric charge is a fundamental property of matter that determines how it interacts with electric fields. It can be positive or negative.

Electrostatic Force

: Electrostatic force refers to the attraction or repulsion between electrically charged objects due to their electric charges.

Negative Charge

: A negative charge refers to an excess of electrons on an object, resulting in an overall negative electrical charge.

Positive Charge

: Positive charge refers to an excess of protons or a deficiency of electrons in an object, resulting in a net positive electric charge. Objects with positive charge repel other positively charged objects and attract negatively charged objects.


© 2024 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.


© 2024 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.