Motion of Charges in E and B Fields

[PatrickGeddes]

Homework Statement

Consider and electron being ejected from the surface of a heated filament at nearly zero speed. Through what potential difference must it be accelerated to achieve a speed of 8.4x10^6 m/s?

Homework Equations

I have found that the equation I should be using is 1/2mv^2=eΔV (where I believe ΔV is m/e?)

The Attempt at a Solution

No attempt finding the equation is the work I have done.

 

[tiny-tim]

Hi Patrick!

(try using the X² button just above the Reply box )

I have found that the equation I should be using is 1/2mv^2=eΔV

yes

(but do you mean that you've worked out that this is the correct equation, or that you found it somewhere and it looks right? )

(where I believe ΔV is m/e?)

no, ∆V is the voltage difference (electric potential difference)

(V means voltage, ∆ means difference in)

 

[tracyellen]

I have a question on this one...what would the mass be? You have the V and e correct but you don't have m??

 

[tracyellen]

OR would the mass be just the standard electron mass at 9.11×10^-31 kg?

 

[tiny-tim]

yup!