An electron is fired at a nonconducting infinite sheet

[Mauve]

Homework Statement

An electron initially 3.00 m from a nonconducting infinite sheet of uniformly distributed charge is fired toward the sheet. The electron has an initial speed of 420 m/s and travels along a line perpendicular to the sheet. When the electron has traveled 2.00 m, its velocity is instantaneously zero, and it then reverses its direction. What is the surface charge density on the sheet?

Relevant Equations

E = σ/(ε_0)

I've been thinking about this problem for some time now and think that I need to find E to solve for σ, but I have no idea how to go about that. How do I approach this problem?

 

[PeroK]

I've been thinking about this problem for some time now and think that I need to find E to solve for σ, but I have no idea how to go about that. How do I approach this problem?

Hint: motion represents kinetic energy.

That said, the field and potential for a uniformly charged sheet is a standard result. Are you sure you don't have it in your notes?

If not, you'll have to derive it through an integration process.

 

[Mauve]

Hint: motion represents kinetic energy.

That said, the field and potential for a uniformly charged sheet is a standard result. Are you sure you don't have it in your notes?

If not, you'll have to derive it through an integration process.

I'm sorry. I'm just unbelievably lost and don't know what you're talking about.

 

[PeroK]

I'm sorry. I'm just unbelievably lost and don't know what you're talking about.

Okay, but we can only help you on here. We can't teach you electromagnetism from the beginning.

Where are you learning this? At university or on your own?