What Is the Velocity of an Electron Between Capacitor Plates?

[missyc8]

Homework Statement

An electron is released from rest at the negative plate of a parallel plate capacitor. The charge per unit area on each plate is σ = 1.70E-7 C/m2, and the plates are separated by a distance of 1.59E-2 m. How fast is the electron moving just before it reaches the positive plate?

Homework Equations

E = σ/2εo
F=q X E
v2 - u2 = 2 a s = 2 (F/m) s

The Attempt at a Solution

E= 1.70E-7/2(8.85E-12)= 9604.52 N/m

F= 1.6E-19 * 9604.52= 1.537E-15 N

v^2= 2(1.537E-15/9.1E-31)*1.59E-2
= 5.370E13...this is wrong...what am i doing wrong??

 

[Delphi51]

Did you remember to take the square root to get v instead of v²?

 

[missyc8]

yes, when i take the sq root, i get 7.328 E6 m/s...still not the answer!

 

[Redbelly98]

Homework Equations

E = σ/2εo

That formula is for a single plate. However, there are two plates here.