What is the velocity of an electron accelerated through 50V?

[Physics_Student]

Simple question;

For an electron, what is its velocity after it has been accelerated through 50V?

I thought about equating 50eV to KE, but I know that's the wrong way, any ideas?

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[vanesch]

For an electron, what is its velocity after it has been accelerated through 50V?
I thought about equating 50eV to KE, but I know that's the wrong way, any ideas?

Why is that wrong ??

cheers,
Patrick.

 

[Physics_Student]

dunno, it doesn't feel right? is that way the correct way?

 

[cepheid]

It's correct because an electron volt is defined as the energy gained by an electron (elementary charge) when accelerated through a potential difference of 1 V. So 50V imparts 50eV to the electron, which is equal to its final kinetic energy. From that you can easily calculate it's final velocity.

 

[Gonzolo]

Don't forget to consider initial energy, velocity, direction etc.

 

[Nenad]

abd don't forget to calculate that using relativistic Kinetic Energy.

 

[zefram_c]

dont forget to calculate that using relativistic Kinetic Energy

I don't think that's needed here; the electron's rest mass is about 0.5MeV and we're talking a KE of 50eV.