# Electric Potential question

• jcpwn2004
In summary, an electron is released from rest 4m from an infinite plane of positive charge and collides with the plane. The electric field produced by the plane has a constant magnitude of 100 V/m. To find the speed of the electron at the point of collision, the force on the electron can be calculated using the equation electric field * charge = force on charge. This force can then be used in the kinematics equation V_f^2 = V_i^2 + 2ad to solve for the final velocity of the electron.
jcpwn2004

## Homework Statement

An electron is released from rest 4m from an infinite plane of positive charge. The plane produces an electric field with a constant magnitude of 100 V/m. How fast is the electron moving when it collides with the plane? Mass of E = 9.11x10^-31kg.

## Homework Equations

Not sure... Ui + Ki = Uf + Kf?

## The Attempt at a Solution

You are given the electric field, not the voltage at the point so you can't use conservation of energy. Remember, electric field * charge = force on charge. You can use this to find the force on the electron, and then use one of the kinematics equations so solve for the speed.

kkrizka said:
You are given the electric field, not the voltage at the point so you can't use conservation of energy. Remember, electric field * charge = force on charge. You can use this to find the force on the electron, and then use one of the kinematics equations so solve for the speed.

Ok so I did F=EfxQ...(100 v/m)(1.6x10-19) = 1.6x10^-13 J. And then F=ma so A = (1.6x10^-17)/(9.11x10-31) = 1.756x10^13 m/s...

I'm lost what to do after that...what kinematic equation should i use?

The one that involves initial, final velocities, acceleration and displacement. I believe it is
$$V_f^2 = V_i^2 + 2ad$$

## 1. What is electric potential?

Electric potential is the amount of electrical potential energy per unit charge at a certain point in an electric field.

## 2. How is electric potential different from electric potential energy?

Electric potential is a property of a point in an electric field, while electric potential energy is a measure of the potential energy that a particle with a certain charge would have at that point.

## 3. What is the unit of electric potential?

The unit of electric potential is volts (V).

## 4. How is electric potential calculated?

Electric potential can be calculated by dividing the electric potential energy by the charge at a certain point in an electric field. It can also be calculated by multiplying the electric field strength by the distance between two points.

## 5. What is the relationship between electric potential and electric potential energy?

Electric potential and electric potential energy have a direct relationship. As the electric potential increases, the electric potential energy also increases. This means that a particle with a higher charge will have a greater electric potential energy at a certain point in an electric field compared to a particle with a lower charge.

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