Speed of an Electron in an Electric Field

[vachan]

Two stationary positive point charges, charge 1 of magnitude 3.75 and charge 2 of magnitude 1.95 , are separated by a distance of 30.0 . An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two charges.

What is the speed of the electron when it is 10.0 from charge 1?
Express your answer in meters per second.




so i have KE = - U
which is

1/2mv^2 = - k Q_1q_2 / r


but then i am confused where should i calculate from?

 

[vachan]

i got it... thanks everyone

 

[Moetasim]

I would approach this problem by first setting up the relevant equations and understanding the physical principles involved. From the given information, we can use Coulomb's law to calculate the electric force between the two charges, which will be acting on the electron. We can also use the equation for the electric field created by a point charge to calculate the strength of the electric field at the midpoint between the two charges.

Next, we can use the equation for the force on a charged particle in an electric field to determine the acceleration of the electron. This will allow us to use the kinematic equations to solve for the speed of the electron at a specific distance from charge 1.

To calculate the speed of the electron when it is 10.0 cm from charge 1, we can use the equation for the electric force between two point charges to determine the force acting on the electron at that distance. From there, we can use Newton's second law to calculate the acceleration of the electron. Finally, using the kinematic equations, we can solve for the speed of the electron at that specific distance.

It is important to note that the speed of the electron will depend on its initial position, as well as the magnitude and separation of the two charges. It will also be constantly changing as it moves along the line connecting the two charges. Therefore, we can only determine the speed of the electron at a specific distance from charge 1, and we cannot determine its overall speed.

In summary, to calculate the speed of the electron at 10.0 cm from charge 1, we will need to use Coulomb's law, the equation for the electric field, the equation for the force on a charged particle in an electric field, and the kinematic equations. The final answer should be expressed in meters per second.