Electric Field Problem: Motion of Charges Near Two Fixed Points

In summary, the initial motion of a third charge released from rest in the vicinity of two fixed point charges, equal in magnitude, will depend on the charge's position in relation to the two charges. A negative charge at point a will accelerate toward the lower-right, a positive charge at point b will accelerate up, a negative charge at point e will accelerate up, a positive charge at point c will accelerate toward the lower-left, and a positive charge at point d will accelerate up. However, the first statement regarding a negative charge at point a is not entirely correct as the electric field line would point straight up at that point.
  • #1
jason.rivera1
1
0
Consider the arrangement of two fixed point charges, equal in magnitude, shown in the figure. Which of the following statements are correct for the initial motion of a third charge if it is released from rest in the vicinity of the two charges shown?

True or False:

A negative charge at point a will accelerate toward the lower-right.
A positive charge at point b will accelerate up.
A negative charge at point e will accelerate up.
A positive charge at point c will accelerate toward the lower-left.
A positive charge at point d will accelerate up.
 

Attachments

  • ef.jpg
    ef.jpg
    2.8 KB · Views: 502
Physics news on Phys.org
  • #2
it might help if you draw electric field lines running from the positive to negative charge to help yourself visualize what is going on.
if you don't know what electric field lines are there is a perfect example of how to draw electric field lines between a positive and negative charge

http://en.wikipedia.org/wiki/File:VFPt_charges_plus_minus_thumb.svg

a positive charge will move in the direction of the arrows, and a negative in the opposite direction.
 
  • #3
A negative charge at point a will accelerate toward the lower-right.
A positive charge at point b will accelerate up.
A negative charge at point e will accelerate up.....these are correct
 
  • #4
brucemaster said:
A negative charge at point a will accelerate toward the lower-right.
A positive charge at point b will accelerate up.
A negative charge at point e will accelerate up.....these are correct

Not sure about the first one. The electric field line would point straight up at that point. A negative charge would be accelerated straight down. Then it would of course move to the right as well, but the problem asked for the initial motion.
 
  • #5


True or False:

A negative charge at point a will accelerate toward the lower-right. True
A positive charge at point b will accelerate up. False
A negative charge at point e will accelerate up. True
A positive charge at point c will accelerate toward the lower-left. False
A positive charge at point d will accelerate up. False

Explanation:

This arrangement of two fixed point charges creates an electric field, which is a region in space where a charged object experiences a force. The direction of the electric field is determined by the direction in which a positive test charge would accelerate. Based on this, we can determine the correct statements as follows:

- A negative charge at point a will accelerate toward the lower-right: True. This is because a negative charge will experience a force in the opposite direction of the electric field, and since the electric field points toward the lower-right, the charge will accelerate in the opposite direction.
- A positive charge at point b will accelerate up: False. This is because a positive charge will experience a force in the same direction as the electric field, and since the electric field points downward, the charge will accelerate downward, not upward.
- A negative charge at point e will accelerate up: True. Similar to point a, a negative charge at point e will experience a force in the opposite direction of the electric field, and since the electric field points downward, the charge will accelerate upward.
- A positive charge at point c will accelerate toward the lower-left: False. This is because a positive charge will experience a force in the same direction as the electric field, and since the electric field points toward the lower-right, the charge will accelerate toward the lower-right, not the lower-left.
- A positive charge at point d will accelerate up: False. This is because a positive charge will experience a force in the same direction as the electric field, and since the electric field points downward, the charge will accelerate downward, not upward.
 

1. What is an electric field?

An electric field is a physical phenomenon that surrounds a charged object and exerts a force on other charged objects within its vicinity.

2. How is an electric field calculated?

The electric field is calculated by dividing the force exerted on a test charge by the magnitude of the test charge. Mathematically, it is represented as E = F/Q, where E is the electric field, F is the force, and Q is the test charge.

3. What is the direction of an electric field?

The direction of an electric field is the direction in which a positive test charge would move if placed in the field. It is always directed away from a positive charge and towards a negative charge.

4. How is an electric field represented?

An electric field is represented by electric field lines, which are imaginary lines that show the direction and strength of the field. The closer the lines are together, the stronger the electric field.

5. How does distance affect the strength of an electric field?

The strength of an electric field decreases as distance from the source increases. This is because the field lines spread out and become less concentrated, resulting in a weaker force on other charged objects.

Similar threads

Replies
3
Views
344
Replies
14
Views
1K
Replies
73
Views
3K
  • Electromagnetism
2
Replies
36
Views
2K
Replies
17
Views
967
Replies
2
Views
831
Replies
2
Views
959
Replies
2
Views
706
Replies
12
Views
971
Replies
2
Views
2K
Back
Top