# Electric Field (velocity of a particle)

• suspenc3
In summary, the conversation discusses the velocity components of an electron moving between two charged parallel plates, the acceleration of the electron, and the velocity of the electron after its x coordinate has changed. The electric field between the plates is given by \vec{E}=(120N/C)j and the equations F=ma and \frac{F}{m}=a_y are used to find the acceleration of the electron. For part b, kinematic equations are used to find the change in velocity and the final velocity of the electron.

## Homework Statement

At some instant in the velocity components of an electron moving between two charged parallel plates are $$v_x=1.5x10^5m/s$$ and $$v_y=3.0x10^3m/s$$. Suppose that the electric field between the plates is given by $$\vec{E}=(120N/C)j$$.

a)what is the acceleration of the electron?

b)what will be the velocity of the electron after its x coordinate has changed by 2.0cm?

## Homework Equations

$$F=ma$$
$$\frac{F}{m}=a_y$$
$$a_y= \frac{q\vec{E}}{m}$$?

## The Attempt at a Solution

Do I just have to sub in the values for part a?

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Yes. I think you have everything you need. Now get started!

so $$a_y = \frac{(1.6x10^{-19}C)((120N/C)j)}{9.1x10^{-31}Kg}$$
$$a_y=(2.108x10^13m/s^2)j$$?

Careful. What sign is the charge on an electron?

righht, negative, so does that mean that it is accelerating downwards?

suspenc3 said:
righht, negative, so does that mean that it is accelerating downwards?

I suppose...is there a horizontal component of the acceleration?

suspenc3 said:
I suppose...is there a horizontal component of the acceleration?

Is there a horizontal component of the field?

thats what I figured, just making sure.

and for part b, would I use :$$\vec{E} = k Q / r2$$?

suspenc3 said:
and for part b, would I use :$$\vec{E} = k Q / r2$$?

No, now that you have the accelerations just use kinematics. How long does it take the electron to go 2cm horizontally? Change in velocity=acceleration*time, etc, etc.

pardon my stupidness, but I've always been bad at this kinematic stuff.
Once I find the change in velocity what do I do?

This is going to make you really feel dumb, but you asked for it. Add the change in the velocity to the initial velocity to get the final velocity?

hahaha, its just one of those days...

## 1. What is an electric field?

An electric field is a physical field that surrounds a charged particle or group of particles. It is a region in which an electric charge experiences a force, either attracting or repelling it. The strength of an electric field is determined by the magnitude and direction of the charges creating it.

## 2. How is the electric field calculated?

The electric field at a point in space is calculated by dividing the force experienced by a test charge at that point by the magnitude of the test charge. This equation is written as E = F/q, where E represents the electric field, F is the force exerted on the charge, and q is the magnitude of the test charge.

## 3. What is the relationship between electric field and velocity of a particle?

The velocity of a particle in an electric field depends on the strength and direction of the electric field, as well as the charge and mass of the particle. As the electric field exerts a force on the charged particle, it will accelerate or decelerate depending on the direction of the force. The greater the electric field, the greater the change in velocity of the particle.

## 4. How does an electric field affect the motion of a charged particle?

An electric field can either accelerate or decelerate a charged particle depending on the direction of the force exerted on the particle. If the electric field and the direction of the particle's motion are parallel, the particle will accelerate. If they are antiparallel, the particle will decelerate. If the electric field and the particle's motion are perpendicular, the particle will experience a force that changes its direction without changing its speed.

## 5. How is the electric field related to the potential energy of a charged particle?

The electric field is directly related to the potential energy of a charged particle. The potential energy of a charged particle in an electric field is equal to the product of the particle's charge and the electric potential at that point in the field. As the electric field does work on the charged particle, it changes its potential energy, either increasing or decreasing it depending on the direction of the force.