Determing the kinetic energy of an electron

[Turion]

Homework Statement

Homework Equations

The Attempt at a Solution

KE_i + PE_i = KE_f
2.4 x 10^-19 + e(1) = KE_f
KE_f = 4.002 x 10^-19 J

So option c would be correct, right? Thank you in advance.

 

[Turion]

This one is a trick question, right? It would need 0 kinetic energy because the electric field itself would move the electron to the left until it reaches point C.

 

[Turion]

This one doesn't even make sense to me. How can the electron go back to plate D if plate D has the higher voltage?

 

[nasu]

Homework Statement

Homework Equations

The Attempt at a Solution

KE_i + PE_i = KE_f
2.4 x 10^-19 + e(1) = KE_f
KE_f = 4.002 x 10^-19 J

So option c would be correct, right? Thank you in advance.

No. The electron is repelled by the negative plate so its KE decreases when it moves from B to A.
And it's easier if you work in eV directly.
The potential difference between B and A is 1 V so the change in potential energy is 1eV.

And I think you are supposed to post one problem per topic.