Parallel Plates - Electron Liberation

[physicsfun_12]

Homework Statement

Hello, I wonder if anyone could check my answer to this problem.

Thanks in advance

An electron is liberated from the lower of two parallel plates separated by a distance of 5mm. The upper plate has a p.d. of 1000v relative to the lower plate. How long does it it take for the electron to reach to upper plate.

Homework Equations

f=ma, f=qe, e=v/d

The Attempt at a Solution

I said F=ma=QE therefore QE=ma and since E=V/d=1000/0.005=2x10⁵

a=3.513x10¹⁶m/s²!

Then using s=ut+1/2at², t=5.335x10^-10s.

Thanks again for any help

Mike

 

[payumooli]

i would take

ma = relativistic mass * dv/dt = qE

solve for v and find time taken

 

[physicsfun_12]

Hello, thanks for your response.

Is that differentiation? Not too sure about how to do that.

Any chance you could get an answer from your method and compare it to mine.

Thanks again,

Mike

 

[payumooli]

4.5*10^-11 s

try it, its really simple