Does Moving in the Same Direction Affect Work Done by an Electric Field?

In summary, if the work done by an electric field is N, then the work done by the person will be negative N if they move the charge against the field lines. However, if they move the charge in the same direction as the electric field, the total work will not be zero and the kinetic energy will increase. This can either slow down or accelerate the particle, resulting in the work done being equal to the final kinetic energy minus what it would have been without interference.
  • #1
Calpalned
297
6
If the work done by an electric field is N, then the work done by me will be negative N? Perhaps this applies if I move a charge against the field lines, but what if I move in the same direction?
 
Physics news on Phys.org
  • #2
I presume the context here is that you are moving an object with negligible kinetic energy so that the net work done by the field plus your hand is zero. That is when the force bu you is opposite to the force by the electric field, and the work done by you will be the negative of the work done by the electric field. If you move the object in the same direction as the electric field is moving it, then certainly, the total work is not zero, the kinetic energy will keep increasing. Nothing prevents you from helping the electric field.
 
  • #3
If you move in the same direction then either:

1. You are pulling the particle against the field, hence slowing it down so that its final KE is less than it would have been if it had been freely moving under the force of the field alone.
2. You are pulling the particle with the field, hence accelerating it even more than the field is so that its final KE is more than it would have been if it had been freely moving under the force of the field alone.

In both cases, the work you have done is equal to the final KE of the particle minus what the final KE would have been if you had not interfered with the particle.
 

FAQ: Does Moving in the Same Direction Affect Work Done by an Electric Field?

What is the sign convention for work?

The sign convention for work is a set of rules used to determine the sign (positive or negative) of work done on an object by an external force. It is based on the direction of the force and the direction of the displacement of the object.

Why is the sign convention for work important?

The sign convention for work is important because it helps us determine whether work is being done on an object or by an object. It also helps us understand the direction of energy transfer in a system.

How is the sign convention for work determined?

The sign convention for work is determined by the direction of the force and the direction of the displacement. If the force and displacement are in the same direction, work is considered positive. If they are in opposite directions, work is considered negative.

What is the significance of a positive work value?

A positive work value indicates that work is being done on an object, meaning energy is being transferred to the object. This could result in an increase in the object's kinetic energy, potential energy, or both.

What is the significance of a negative work value?

A negative work value indicates that work is being done by an object, meaning energy is being transferred from the object. This could result in a decrease in the object's kinetic energy, potential energy, or both.

Back
Top